Cancer types and symptoms

Signs and Symptoms of Cancer

What are signs and symptoms?

Signs and symptoms are both signals of injury, illness, disease – signals that something is not right in the body.

A sign is a signal that can be seen by someone else – maybe a loved one, or a doctor, nurse, or other health care professional. For example, fever, fast breathing, and abnormal lung sounds heard through a stethoscope may be signs of pneumonia.

A symptom is a signal that’s felt or noticed by the person who has it, but may not be easily seen by anyone else. For example, weakness, aching, and feeling short of breath may be symptoms of pneumonia.

Having one sign or symptom may not be enough to figure out what’s causing it. For example, a rash in a child could be a sign of a number of things, such as poison ivy, measles, a skin infection, or a food allergy. But if the child has the rash along with other signs and symptoms like a high fever, chills, achiness, and a sore throat, then a doctor can get a better picture of the illness. Sometimes, a patient’s signs and symptoms still don’t give the doctor enough clues to be sure what’s causing the illness. Then medical tests, such as x-rays, blood tests, or a biopsy may be needed.

How does cancer cause signs and symptoms?

Cancer is a group of diseases that can cause almost any sign or symptom. The signs and symptoms will depend on where the cancer is, how big it is, and how much it affects the organs or tissues. If a cancer has spread (metastasized), signs or symptoms may appear in different parts of the body.

As a cancer grows, it can begin to push on nearby organs, blood vessels, and nerves. This pressure causes some of the signs and symptoms of cancer. If the cancer is in a critical area, such as certain parts of the brain, even the smallest tumor can cause symptoms.

But sometimes cancer starts in places where it won’t cause any signs or symptoms until it has grown quite large. Cancers of the pancreas, for example, usually don’t cause symptoms until they grow large enough to press on nearby nerves or organs (this causes back or belly pain). Others may grow around the bile duct and block the flow of bile. This causes the eyes and skin to look yellow (jaundice). By the time a pancreatic cancer causes signs or symptoms like these, it’s usually in an advanced stage. This means it has grown and spread beyond the place it started – the pancreas.

A cancer may also cause symptoms like fever, extreme tiredness (fatigue), or weight loss. This may be because cancer cells use up much of the body’s energy supply, or they may release substances that change the way the body makes energy from food. Cancer can also cause the immune system to react in ways that produce these signs and symptoms.

Sometimes, cancer cells release substances into the bloodstream that cause symptoms that are not usually linked to cancer. For example, some cancers of the pancreas can release substances that cause blood clots in veins of the legs. Some lung cancers make hormone-like substances that raise blood calcium levels. This affects nerves and muscles, making the person feel weak and dizzy.

How are signs and symptoms helpful?

Treatment works best when cancer is found early – while it’s still small and is less likely to have spread to other parts of the body. This often means a better chance for a cure, especially if the cancer can be removed with surgery.

A good example of the importance of finding cancer early is melanoma skin cancer. It can be easy to remove if it has not grown deep into the skin. The 5-year survival rate (percentage of people who live at least 5 years after diagnosis) at this early stage is around 98%. Once melanoma has spread to other parts of the body, the 5-year survival rate drops to about 16%.

Sometimes people ignore symptoms. Maybe they don’t know that the symptoms could mean something is wrong. Or they might be frightened by what the symptoms could mean and don’t want to get medical help. Maybe they just can’t afford to get medical care.

Some symptoms, such as tiredness or coughing, are more likely caused by something other than cancer. Symptoms can seem unimportant, especially if there’s a clear cause or the problem only lasts a short time. In the same way, a person may reason that a symptom like a breast lump is probably a cyst that will go away by itself. But no symptom should be ignored or overlooked, especially if it has lasted a long time or is getting worse.

Most likely, symptoms are not caused by cancer, but it’s important to have them checked out, just in case. If cancer is not the cause, a doctor can help figure out what the cause is and treat it, if needed.

Sometimes, it’s possible to find cancer before having symptoms. The American Cancer Society and other health groups recommend cancer-related check-ups and certain tests for people even though they have no symptoms. This helps find certain cancers early, before symptoms start. For more information on early detection tests, see our document called American Cancer Society Guidelines for the Early Detection of Cancer. But keep in mind, even if you have these recommended tests, it’s still important to see a doctor if you have any symptoms.

What are some general signs and symptoms of cancer?

You should know some of the general signs and symptoms of cancer. But remember, having any of these does not mean that you have cancer – many other things cause these signs and symptoms, too. If you have any of these symptoms and they last for a long time or get worse, please see a doctor to find out what’s going on.

Unexplained weight loss

Most people with cancer will lose weight at some point. When you lose weight for no known reason, it’s called an unexplained weight loss. An unexplained weight loss of 10 pounds or more may be the first sign of cancer. This happens most often with cancers of the pancreas, stomach, esophagus (swallowing tube), or lung.


Fever is very common with cancer, but it more often happens after cancer has spread from where it started. Almost all people with cancer will have fever at some time, especially if the cancer or its treatment affects the immune system. (This can make it harder for the body to fight infection.) Less often, fever may be an early sign of cancer, such as blood cancers like leukemia or lymphoma.


Fatigue is extreme tiredness that doesn’t get better with rest. It may be an important symptom as cancer grows. But it may happen early in some cancers, like leukemia. Some colon or stomach cancers can cause blood loss that’s not obvious. This is another way cancer can cause fatigue.


Pain may be an early symptom with some cancers like bone cancers or testicular cancer. A headache that does not go away or get better with treatment may be a symptom of a brain tumor. Back pain can be a symptom of cancer of the colon, rectum, or ovary. Most often, pain due to cancer means it has already spread (metastasized) from where it started.

Skin changes

Along with skin cancers, some other cancers can cause skin changes that can be seen. These signs and symptoms include:

  • Darker looking skin (hyperpigmentation)
  • Yellowish skin and eyes (jaundice)
  • Reddened skin (erythema)
  • Itching (pruritis)
  • Excessive hair growth

Signs and symptoms of certain cancers

Along with the general symptoms, you should watch for certain other common signs and symptoms that could suggest cancer. Again, there may be other causes for each of these, but it’s important to see a doctor about them as soon as possible – especially if there’s no other cause you can identify, the problem lasts a long time, or it gets worse over time.

Change in bowel habits or bladder function

Long-term constipation, diarrhea, or a change in the size of the stool may be a sign of colon cancer. Pain when passing urine, blood in the urine, or a change in bladder function (such as needing to pass urine more or less often than usual) could be related to bladder or prostate cancer. Report any changes in bladder or bowel function to a doctor.

Sores that do not heal

Skin cancers may bleed and look like sores that don’t heal. A long-lasting sore in the mouth could be an oral cancer. This should be dealt with right away, especially in people who smoke, chew tobacco, or often drink alcohol. Sores on the penis or vagina may either be signs of infection or an early cancer, and should be seen by a health professional.

White patches inside the mouth or white spots on the tongue

White patches inside the mouth and white spots on the tongue may be leukoplakia. Leukoplakia is a pre-cancerous area that’s caused by frequent irritation. It’s often caused by smoking or other tobacco use. People who smoke pipes or use oral or spit tobacco are at high risk for leukoplakia. If it’s not treated, leukoplakia can become mouth cancer. Any long-lasting mouth changes should be checked by a doctor or dentist right away.

Unusual bleeding or discharge

Unusual bleeding can happen in early or advanced cancer. Coughing up blood may be a sign of lung cancer. Blood in the stool (which can look like very dark or black stool) could be a sign of colon or rectal cancer. Cancer of the cervix or the endometrium (lining of the uterus) can cause abnormal vaginal bleeding. Blood in the urine may be a sign of bladder or kidney cancer. A bloody discharge from the nipple may be a sign of breast cancer.

Thickening or lump in the breast or other parts of the body

Many cancers can be felt through the skin. These cancers occur mostly in the breast, testicle, lymph nodes (glands), and the soft tissues of the body. A lump or thickening may be an early or late sign of cancer and should be reported to a doctor, especially if you’ve just found it or notice it has grown in size. Keep in mind that some breast cancers show up as red or thickened skin rather than a lump.

Indigestion or trouble swallowing

Indigestion or swallowing problems that don’t go away may be signs of cancer of the esophagus (the swallowing tube that goes to the stomach), stomach, or pharynx (throat). But like most symptoms on this list, they are most often caused by something other than cancer.

Recent change in a wart or mole or any new skin change

Any wart, mole, or freckle that changes color, size, or shape, or that loses its sharp border should be seen by a doctor right away. Any other skin changes should be reported, too. A skin change may be a melanoma which, if found early, can be treated successfully. See pictures of skin cancers and other skin conditions in our Skin Cancer Image Gallery.

Nagging cough or hoarseness

A cough that does not go away may be a sign of lung cancer. Hoarseness can be a sign of cancer of the larynx ( voice box) or thyroid gland.

Other symptoms

The signs and symptoms listed above are the more common ones seen with cancer, but there are many others that are not listed here. If you notice any major changes in the way your body works or the way you feel – especially if it lasts for a long time or gets worse – let a doctor know. If it has nothing to do with cancer, the doctor can find out more about what’s going on and, if needed, treat it. If it is cancer, you’ll give yourself the chance to have it treated early, when treatment works best.


Jump to: Causes | Symptoms | Types of cancer | Stages | Treatment | Can cancer be cured? | Chances of getting cancer | Occurence

What is cancer?

Cancer is a disease that occurs when malignant (or dangerous) cells grow in the body. These cells can form almost anywhere, including the brain, lungs, pancreas, and more. Cancerous cells cluster together to form a mass called a tumor and can spread throughout the body to other, more distant areas. Although some cancers can be fatal, others can be successfully treated with procedures like surgery and chemotherapy.

What causes cancer?

It’s not always possible to identify the exact reason why someone developed cancer. However, there are certain risk factors that can increase a person’s chance of developing the disease. Generally speaking, these can either be hereditary or environmental—i.e., cancer may either “run in the family” or can be caused by exposure to sunlight, radiation, or tobacco smoke. There are some cancer risk factors that people have some control over (avoiding cigarette smoke, for example) and others that they don’t (like age). Here are some of the factors thought to cause cancer.


Cancer is caused by changes that occur in a person’s genes. First, some background: Humans have an estimated 20,000 to 25,000 genes, all of which are made up of DNA. Think of DNA as a kind of blueprint. It’s the code that tells your genes how to make proteins, the molecules that maintain and support the organs and tissue in the body.

If a person’s DNA “mutates” or changes—a result of, say, the harmful chemicals in tobacco smoke or UV rays from the sun—the information in the gene becomes rearranged or deleted. Called DNA mutations, these errors can then cause the growth of cancerous cells, which multiply throughout the body.

But a person can also be born with genetic mutations. The National Cancer Institute (NCI) estimates that about 5% to 10% of all cancers are caused by gene mutations that were inherited from the person’s mother or father. People who have inherited mutations in the BRCA1 and BRCA2 genes, for example, are more likely to develop breast and ovarian cancer than those whose DNA does not contain these mutations. That’s why some people may want to be tested for these inherited gene mutations, particularly if a certain type of cancer runs in the family.


Although people can develop cancer at any age, 87% of all cancers in the United States are diagnosed in people who are at least 50 years old, according to the American Cancer Society (ACS). The median age at which breast cancer is diagnosed is age 61; for prostate cancer, it’s age 66; for colorectal cancer, it’s age 68; and for lung cancer, it’s age 70, according to the NCI.


The energy from the sun is called ultraviolet or UV radiation, and it reaches Earth in two forms: in UVA and UVB rays. Both can damage the DNA in a person’s skin cells and is a major risk factor for skin cancer. Sunlamps and tanning beds are other sources of UV rays.


X-rays and gamma rays are two other types of radiation–both of which are found naturally and in man-made devices like imaging tests, scanners, and certain power plants–that can cause DNA mutations, which may lead to cancer in the future.


Tobacco smoke contains at least 69 cancer-causing chemicals, including arsenic and formaldehyde. Not only is smoking the leading cause of lung cancer—about 80% to 90% of deaths from this disease are linked to smoking, according to the American Lung Association—but it’s also linked to cancers of the lung, esophagus, larynx, mouth, throat, kidney, liver, pancreas, stomach, and more.

RELATED: 7 Causes of Lung Cancer in Non-Smokers

Other carcinogens

Like tobacco smoke, radiation, and UV rays, other chemicals, like asbestos and soot, can cause mutations in a person’s DNA. Those DNA mutations can eventually trigger the growth of cancerous cells. Where you live and what you do for work may contribute to your exposure to certain carcinogens.

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General signs and symptoms of cancer

Cancer can cause almost any type of symptom—everything from fatigue to pain to shortness of breath and more. In some cases, a person with cancer will notice symptoms during the early stages of the disease, but in other instances, the cancer can go unnoticed until the tumor has either grown in size (putting pressure on an organ, for example) or spread to other areas in the body. Doctors, too, can spot some of the warning signs of cancer: They may notice a lump or lesion on a patient’s body or uncover an abnormal mass of cells on a routine imaging test. Signs and symptoms of cancer include:

A lump

Some cancers can be felt underneath the skin, especially tumors that start in the breast. If you’re wondering what a cancer lump feels like, know that most of the time lumps are not cancer—in fact, normal breast tissue can feel lumpy too.

Breast cancer lumps can feel as if the tissue in or near your breast (or under your arm) is thick or firm. The NCI says that if a person notices these signs, they should check the other breast to see whether it yields a similar feel. If both breasts feel the same, the lumps may be normal. However, if you notice a change in your breast, talk to your doctor.

Bleeding or discharge

Bleeding can occur in both the early stages of cancer or the later stages. Depending on the type of cancer, people can notice blood in their stool (a possible sign of colorectal cancer), their urine (a symptom of bladder or kidney cancer) or in the mucus that accompanies a cough (a sign of lung cancer). Abnormal discharge from the nipple may signal breast cancer.

RELATED: 25 Breast Cancer Myths Busted

Unusual bowel or bladder habits

Colon cancer can trigger symptoms like rectal bleeding, blood in the stool, cramping in the lower abdomen, or pain when passing urine. Painful urination or other changes in bladder function may also be signs of bladder or prostate cancer.

A lingering cough or hoarseness

One common sign of lung cancer is a cough that won’t go away or continues to get worse. Lung, larynx (voice box), and thyroid cancer can also cause changes to a person’s voice, making it seem raspy.

Skin changes

A mole or skin lesion that has changed size, shape, or color could be a sign of skin cancer. Basal cell carcinoma may appear as a red or pink growth, while squamous cell carcinoma can have a rough surface. The warning signs of melanoma—a particularly dangerous form of skin cancer—include a sore that doesn’t heal, is painful, oozes, or bleeds.

Other cancers can also cause changes to the skin. Jaundice, or the yellowing of the eyes and skin, can be a sign of pancreatic cancer, and excessive hair growth can be a sign of adrenal cancer.

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Cancer can develop in almost any area of the body. In most cases, the cancer is named after the organs or tissues in which it first develops—for example, breast cancer refers to the growth of cancerous cells in the breast tissue, whereas prostate cancer refers to the growth of cancerous cells in the prostate gland.

More than 852,000 women are estimated to develop cancer each year, according to the ACS, and about half of them will be diagnosed with either breast, colorectal, or lung and bronchus cancer. Although fewer men will develop cancer—more than 836,000 are diagnosed yearly, most with either prostate or lung and bronchus cancer—their diseases tend to be more fatal. An estimated 318,420 men will die of cancer yearly compared to 282,500 women. In both males and females, the deadliest form of cancer is lung cancer.

There are more than 100 types of cancers, some of which—like lip, tongue, and gallbladder cancer—are rare. The most commonly diagnosed types of cancer include:

  • Bladder cancer
  • Breast cancer
  • Colon and rectal cancer
  • Endometrial cancer
  • Kidney cancer
  • Leukemia
  • Liver cancer
  • Lung cancer
  • Melanoma
  • Non-Hodgkin lymphoma
  • Nonmelanoma skin cancer
  • Pancreatic cancer
  • Prostate cancer
  • Thyroid cancer

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Stages of cancer

After a person is diagnosed with cancer, doctors will assign the disease a “stage.” This process (called “staging”) helps doctors quantify how much cancer is in the body and determine which type of treatment a person should receive.

There are five stages of cancer: stage 0 (or, carcinoma in situ), stage 1, stage 2, stage 3, and stage 4. Lower stages indicate that the disease is more localized, or contained, whereas higher stages refer to cancers that have spread into other areas of the body. As a general rule, early-stage cancers are more likely to be successfully treated than later-stage cancers.

The most common method of staging cancers is the TNM system, developed by the American Joint Committee on Cancer. The T denotes information about the tumor itself, including the size or whether it has invaded any nearby tissue. The N specifies whether the cancer has spread into the lymph nodes (structures in the body that contain immune cells) and how many lymph nodes are affected. Lastly, the M refers to how far the cancer has metastasized (or spread) to distant areas of the body. Each letter is followed by a number, which further describes how far the cancer has spread or grown. For example, a person with stage 1 colorectal cancer may be assigned a grade of T1, N0, M0, meaning that the tumor may have grown into one of the muscle layers in the gastrointestinal tract but hasn’t spread to nearby lymph nodes or other, more distant areas of the body. Doctors will take all of this information into account and classify the cancer as stage 1, 2, 3, or 4.

RELATED: Cervical Cancer: 9 Symptoms Every Woman Needs to Know

One important note: The stage of a person’s cancer does not change, even if the tumor shrinks or the disease has metastasized. Doctors will always refer to the cancer as the stage in which it was first diagnosed and will describe any further changes to the disease by changing the numbers in the TNM system.

Stage 4 cancer

Also known as metastatic cancer, this type of cancer has spread to distant organs and lymph nodes in the body. One example: In stage 4 breast cancer, the tumor may have spread from the breast to the bones, brain, liver, or lungs. Common treatments for stage 4 cancers include chemotherapy, radiation therapy, and surgery. While different types of cancers have different survival rates, in general, it can be challenging to treat the disease if it was detected at this late stage.

Stage 3 cancer

At stage 3, cancer may have spread to the lymph nodes, but it hasn’t metastasized to more distant areas of the body. In women with stage 3 breast cancer, for example, the cancer might have invaded the chest wall and reached the nearby lymph nodes, but it hasn’t spread to other areas of the body, like the brain or bones.

Stage 2 cancer

Broadly speaking, stage 2 cancers may have penetrated the walls of the surrounding muscle tissue and infiltrated a small number of very nearby lymph nodes, but they haven’t reached more distant lymph nodes or other areas of the body. Doctors may refer to some stage 2 cancers as “localized” cancer, in which the cancerous cells are only found in the tissue or organ where the disease began. In women with stage 2 breast cancer, for example, the tumor may be less than five centimeters in length but it hasn’t reached any lymph nodes or other parts of the body.

Stage 1 cancer

Often referred to as early-stage cancer, stage 1 cancers haven’t spread beyond the area of the body in which they were first detected. For women with stage 1 breast cancer, the tumor hasn’t spread out of the breast, although it might have spread to the close-by lymph nodes near the armpit. In general, it’s easier to treat earlier-stage cancers than the tumors that are more advanced; options can include surgery and chemotherapy, among others.

Stage 0 cancer

Also known as carcinoma in situ, stage 0 cancer is defined as a group of abnormal cells that hasn’t spread to other surrounding areas of the body. Stage 0 cells are sometimes called pre-cancerous cells. These cells may or may not become cancerous in the future; they can be removed early with treatments like surgery or radiation therapy.

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For example, women with stage 0 breast cancer may have ductal carcinoma in situ or DCIS, in which abnormal cells have developed in the lining of a breast duct. In this case, the cells have not spread to the surrounding breast tissue but may do so at a later time.

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Cancer treatment

Doctors will determine which treatment a person should receive based on the type and stage of the cancer. Some people may only need one treatment, whereas others may need multiple forms of therapy.

Surgery is one of the most common types of cancer treatments and is often performed on localized tumors that haven’t spread to other areas of the body. The surgery can be “open”—meaning, the doctor will make a large cut to remove the tumor, surrounding healthy tissue, and nearby lymph nodes all at once—or “minimally invasive,” in which a surgeon can use special tools to remove the growths by making a few smaller cuts.

Radiation therapy is another type of cancer treatment that’s used to kill or shrink cancer cells. Radiation may be used by itself or in combination with surgery or chemotherapy. Because radiation therapy can also damage nearby healthy cells, many people experience side effects like fatigue, hair loss, nausea, and more.

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Doctors can also kill cancerous cells with drugs. Known as chemotherapy (or, colloquially, chemo), this treatment can be given in a number of ways, including intravenously, topically, or orally, in the form of pills or liquids. Like radiation therapy, this treatment can also cause side effects like nausea and hair loss.

Other cancer treatment options include hormone therapy (used to treat some prostate and breast cancers) and immunotherapy (which helps bolster a person’s immune system so they can better fight the disease). Lastly, some people may be eligible to join clinical trials, or studies in which experts are conducting cancer research and testing new treatments.

Although there is currently no cure for cancer, per se, these treatments can help put some cancers into remission and possibly eradicate them for good.

Is cancer ever really “cured”?

In general, doctors can’t say for sure that a person’s cancer is cured. That’s because there’s no guarantee that the disease will never return.

However, most cancers that do return will come back within five years. Therefore, if a person’s cancer has remained in complete remission—meaning, there have been no signs and symptoms of cancer—for longer than that time period, the cancer may never return.

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Chances of getting cancer

It’s not always clear why some people develop cancer and others do not. Although the odds of getting certain cancers can be higher in certain populations—for example, those who smoke are approximately 20 times more likely to develop lung cancer as those who don’t smoke—the ACS estimates that the average woman has a one in three chance of developing cancer and a one in five chance of dying from cancer.

About one out of every eight women will develop breast cancer, and one in 37 may die from it. Likewise, one in every 17 women will develop lung (or bronchus) cancer, and one in 20 may die of the disease. The odds of a woman getting colorectal cancer are one in 23, whereas the odds of dying from it are one in 55.

RELATED: The 12 Best Ways to Prevent Colorectal Cancer

Roughly one in two men will develop cancer, and one in four will die from the disease. About one in seven men will develop prostate cancer, which may be fatal in about one out of every 39 men. Lung cancer will develop in about one in 14 men, claiming the lives of one in 16. Lastly, about one in 21 men will be diagnosed with colorectal cancer, and one in 50 are estimated to die of it.

How many people die from cancer each year?

Cancer is the second leading cause of death in the United States, claiming the lives of nearly one in four Americans. (Heart disease is currently the most fatal condition.) The ACS estimates that about 600,920 Americans die from cancer every year. That’s almost 1,650 per day.

Throughout most of the 20th century, the rate of cancer deaths continued to climb, largely due to the popularity of smoking. The good news: Thanks to new treatments, advancements in early detection and screening, and the flurry of anti-smoking campaigns, the number of deaths due to cancer have been declining since they peaked in 1991. Then, the disease claimed the lives of about one in 465 people; by 2014, that number had fallen to one out of every 621 people.

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18 Cancer Symptoms

More Cancer Signs and Symptoms

  • Blood in the urine
    • Hematuria or blood in the urine can be caused by urinary infection, kidney stones, or other causes.
    • The blood could be visible by the naked eye or might be found on a urine examination (microscopic hematuria).
    • For some people, it is a symptom of cancer of the bladder or kidney.
    • Any episode of blood in the urine should be investigated.
  • Hoarseness
    • Hoarseness not caused by a respiratory infection or that lasts longer than three to four weeks should be evaluated.
    • Hoarseness can be caused by simple allergy or by vocal cord polyps, but it could also be the first sign of cancer of the throat.
  • Persistent lumps or swollen glands
    • Lumps most frequently represent harmless conditions such as a benign cyst. A doctor should examine any new lump or a lump that won’t go away.
    • Lumps may represent cancer or a swollen lymph gland related to cancer.
    • Lymph nodes swell from infection and other causes and may take weeks to shrink again.
    • A lump or gland that remains swollen for three to four weeks should be evaluated.
  • Obvious change in a wart or a mole
    • Multicolored moles that have irregular edges or bleed may be cancerous.
    • Larger moles are more worrisome and need to be evaluated, especially if they seem to be enlarging.
    • Removing a mole is usually simple. You should have your doctor evaluate any suspicious mole for removal. The doctor will send it for examination under a microscope for skin cancer.
  • Indigestion or difficulty swallowing
    • Most people with chronic heartburn usually do not have serious problems.
    • People who suffer from chronic or lasting symptoms despite using over-the-counter antacids may need to have an upper GI endoscopy.
    • A condition called Barrett esophagus, which can lead to cancer of the esophagus, can be treated with medication and then monitored by a doctor.
    • Difficulty swallowing is a common problem, especially in elderly people, and has many causes.
      • Swallowing problems need to be investigated, because nutrition is always important.
      • Difficulty swallowing solids can be seen with cancer of the esophagus.
  • Unusual vaginal bleeding or discharge
    • Unusual vaginal bleeding or bloody discharge may be an early sign of cancer of the uterus. Women should be evaluated when they have bleeding after intercourse or bleeding between periods.
    • Bleeding that comes back, that lasts two or more days longer than expected, or that is heavier than usual also merits medical examination.
    • Postmenopausal bleeding, unless expected on hormone therapy, is also worrisome and should be evaluated.
    • Usually, the evaluation will include an endometrial biopsy, in which a doctor takes a small tissue sample from inside the uterus for testing.
    • A Pap smear should be part of every woman’s routine medical care.
  • Unexpected weight loss, night sweats, or fever
    • These nonspecific symptoms might be present with several different types of cancer. Pancreatic cancer can appear with weight loss and no specific pain.
    • Various infections can lead to similar symptoms (for example, tuberculosis).
  • Continued itching in the anal or genital area
    • Precancerous or cancerous conditions of the skin of the genital or anal areas can cause persistent itching.
    • Some cancers cause skin color changes.
    • Several infections or skin conditions (for example, fungal infections or psoriasis) also can cause these symptoms. If itching does not stop with over-the-counter topical medications, your doctor should inspect the area.
  • Nonhealing sores
    • Sores generally heal quickly. If an area fails to heal, you may have cancer and should see a doctor.
    • Nonhealing sores in your mouth or persistent white or red patches on your gums, tongue, or tonsils are also should raise concerns.
    • Some nonhealing sores may be due to poor circulation (for example, diabetic foot ulcers).
  • Headaches
    • Headaches have many causes (for example, migraines, aneurysms) but cancer is not a common one.
    • A severe unrelenting headache that feels different from usual can be a sign of cancer, but aneurysms may present in the same way.
    • If your headache fails to improve with over-the-counter medications, see a doctor promptly.
  • Back pain, pelvic pain, bloating, or indigestion
    • These are common symptoms of daily life, often related to food intake, muscle spasms or strains, but they also can be seen in ovarian cancer.
    • Ovarian cancer is particularly difficult to treat, because it is frequently diagnosed late in the course of the disease.
    • The American Cancer Society and other organizations have been trying to make both patients and physicians more aware and consider this diagnosis if the classic symptoms are present.


Properties of Cancer Cells

The uncontrolled growth of cancer cells results from accumulated abnormalities affecting many of the cell regulatory mechanisms that have been discussed in preceding chapters. This relationship is reflected in several aspects of cell behavior that distinguish cancer cells from their normal counterparts. Cancer cells typically display abnormalities in the mechanisms that regulate normal cell proliferation, differentiation, and survival. Taken together, these characteristic properties of cancer cells provide a description of malignancy at the cellular level.

The uncontrolled proliferation of cancer cells in vivo is mimicked by their behavior in cell culture. A primary distinction between cancer cells and normal cells in culture is that normal cells display density-dependent inhibition of cell proliferation (Figure 15.8). Normal cells proliferate until they reach a finite cell density, which is determined in part by the availability of growth factors added to the culture medium (usually in the form of serum). They then cease proliferating and become quiescent, arrested in the G0 stage of the cell cycle (see Figure 14.6). The proliferation of most cancer cells, however, is not sensitive to density-dependent inhibition. Rather than responding to the signals that cause normal cells to cease proliferation and enter G0, tumor cells generally continue growing to high cell densities in culture, mimicking their uncontrolled proliferation in vivo.

Figure 15.8

Density-dependent inhibition. Normal cells proliferate in culture until they reach a finite cell density, at which point they become quiescent. Tumor cells, however, continue to proliferate independent of cell density.

A related difference between normal cells and cancer cells is that many cancer cells have reduced requirements for extracellular growth factors. As discussed in Chapter 13, the proliferation of most cells is controlled, at least in part, by polypeptide growth factors. For some cell types, particularly fibroblasts, the availability of serum growth factors is the principal determinant of their proliferative capacity in culture. The growth factor requirements of these cells are closely related to the phenomenon of density-dependent inhibition, since the density at which normal fibroblasts become quiescent is proportional to the concentration of serum growth factors in the culture medium.

The growth factor requirements of many tumor cells are reduced compared to their normal counterparts, contributing to the unregulated proliferation of tumor cells both in vitro and in vivo. In some cases, cancer cells produce growth factors that stimulate their own proliferation (Figure 15.9). Such abnormal production of a growth factor by a responsive cell leads to continuous autostimulation of cell division (autocrine growth stimulation), and the cancer cells are therefore less dependent on growth factors from other, physiologically normal sources. In other cases, the reduced growth factor dependence of cancer cells results from abnormalities in intracellular signaling systems, such as unregulated activity of growth factor receptors or other proteins (e.g., Ras proteins or protein kinases) that were discussed in Chapter 13 as elements of signal transduction pathways leading to cell proliferation.

Figure 15.9

Autocrine growth stimulation. A cell produces a growth factor to which it also responds, resulting in continuous stimulation of cell proliferation.

Cancer cells are also less stringently regulated than normal cells by cell-cell and cell-matrix interactions. Most cancer cells are less adhesive than normal cells, often as a result of reduced expression of cell surface adhesion molecules. For example, loss of E-cadherin, the principal adhesion molecule of epithelial cells, is important in the development of carcinomas (epithelial cancers). As a result of reduced expression of cell adhesion molecules, cancer cells are comparatively unrestrained by interactions with other cells and tissue components, contributing to the ability of malignant cells to invade and metastasize. The reduced adhesiveness of cancer cells also results in morphological and cytoskeletal alterations: Many tumor cells are rounder than normal, in part because they are less firmly attached to either the extracellular matrix or neighboring cells.

A striking difference in the cell-cell interactions displayed by normal cells and those of cancer cells is illustrated by the phenomenon of contact inhibition (Figure 15.10). Normal fibroblasts migrate across the surface of a culture dish until they make contact with a neighboring cell. Further cell migration is then inhibited, and normal cells adhere to each other, forming an orderly array of cells on the culture dish surface. Tumor cells, in contrast, continue moving after contact with their neighbors, migrating over adjacent cells, and growing in disordered, multilayered patterns. Not only the movement but also the proliferation of many normal cells is inhibited by cell-cell contact, and cancer cells are characteristically insensitive to such contact inhibition of growth.

Figure 15.10

Contact inhibition. Light micrographs (left) and scanning electron micrographs (right) of normal fibroblasts and tumor cells. The migration of normal fibroblasts is inhibited by cell contact, so they form an orderly side-by-side array on the surface of (more…)

Two additional properties of cancer cells affect their interactions with other tissue components, thereby playing important roles in invasion and metastasis. First, malignant cells generally secrete proteases that digest extracellular matrix components, allowing the cancer cells to invade adjacent normal tissues. Secretion of collagenase, for example, appears to be an important determinant of the ability of carcinomas to digest and penetrate through basal laminae to invade underlying connective tissue (see Figure 15.5). Second, cancer cells secrete growth factors that promote the formation of new blood vessels (angiogenesis). Angiogenesis is needed to support the growth of a tumor beyond the size of about a million cells, at which point new blood vessels are required to supply oxygen and nutrients to the proliferating tumor cells. Such blood vessels are formed in response to growth factors, secreted by the tumor cells, that stimulate proliferation of endothelial cells in the walls of capillaries in surrounding tissue, resulting in the outgrowth of new capillaries into the tumor. The formation of such new blood vessels is important not only in supporting tumor growth, but also in metastasis. The actively growing new capillaries formed in response to angiogenic stimulation are easily penetrated by the tumor cells, providing a ready opportunity for cancer cells to enter the circulatory system and begin the metastatic process.

Another general characteristic of most cancer cells is that they fail to differentiate normally. Such defective differentiation is closely coupled to abnormal proliferation, since, as discussed in Chapter 14, most fully differentiated cells either cease cell division or divide only rarely. Rather than carrying out their normal differentiation program, cancer cells are usually blocked at an early stage of differentiation, consistent with their continued active proliferation.

The leukemias provide a particularly good example of the relationship between defective differentiation and malignancy. All of the different types of blood cells are derived from a common stem cell in the bone marrow (see Figure 14.44). Descendants of these cells then become committed to specific differentiation pathways. Some cells, for example, differentiate to form erythrocytes whereas others differentiate to form lymphocytes, granulocytes, or macrophages. Cells of each of these types undergo several rounds of division as they differentiate, but once they become fully differentiated, cell division ceases. Leukemic cells, in contrast, fail to undergo terminal differentiation (Figure 15.11). Instead, they become arrested at early stages of maturation at which they retain their capacity for proliferation and continue to reproduce.

Figure 15.11

Defective differentiation and leukemia. Different types of blood cells develop from a multipotential (pluripotent) stem cell in the bone marrow. The precursors of differentiated cells undergo several rounds of cell division as they mature, but cell division (more…)

As discussed in Chapter 13, programmed cell death, or apoptosis, is an integral part of the differentiation program of many cell types, including blood cells. Many cancer cells fail to undergo apoptosis, and therefore exhibit increased life spans compared to their normal counterparts. This failure of cancer cells to undergo programmed cell death contributes substantially to tumor development. For example, the survival of many normal cells is dependent on signals from growth factors or from the extracellular matrix that prevent apoptosis. In contrast, tumor cells are often able to survive in the absence of growth factors required by their normal counterparts. Such a failure of tumor cells to undergo apoptosis when deprived of normal environmental signals may be important not only in primary tumor development but also in the survival and growth of metastatic cells in abnormal tissue sites. Normal cells also undergo apoptosis following DNA damage, while many cancer cells fail to do so. In this case, the failure to undergo apoptosis contributes to the resistance of cancer cells to irradiation and many chemotherapeutic drugs, which act by damaging DNA. Abnormal cell survival, as well as cell proliferation, thus plays a major role in the unrelenting growth of cancer cells in an animal.

What are the main types of cancer?

Dr Sarah Jarvis MBE

What are the different types of cancer?

There are more than 100 different types of cancer. Each type is classified by the type of cell the cancer originates from. For example, a breast cell, a lung cell, etc. Each type of cancer generally falls into one of three categories:

  • Carcinomas are cancers that arise from cells which line a body surface, or the lining of a gland – for example, the skin, or the lining of the gut, mouth, neck of the womb (cervix), airways, etc.
  • Sarcomas are cancers that arise from cells which make up the connective tissues such as bones or muscles. For example, an osteosarcoma is a cancer of bone tissue.
  • Leukaemias and lymphomas are cancers of cells in bone marrow and lymph glands. For example, leukaemia is a cancer of cells that make white blood cells.
List of Cancers

The five most common cancers in the UK are Breast Cancer, Lung Cancer, Prostate Cancer, Bowel Cancer and Skin Cancer – but there are many more types. Links to detailed leaflets on each are provided below:

  • Bladder Cancer
  • Brain Cancer and Brain Tumours
  • Breast Cancer
  • Cancer of the Uterus (Endometrial Cancer)
  • Cervical Cancer
  • Childhood Leukaemia
  • Colon, Rectal and Bowel Cancer (Colorectal Cancer)
  • Gynaecological Cancer
  • Hodgkin’s Lymphoma
  • Kidney Cancer
  • Leukaemia
  • Lung Cancer
  • Mouth Cancer (Oral Cancer)
  • Neck Lumps and Bumps
  • Neuroblastoma
  • Non-Hodgkin’s Lymphoma
  • Oesophageal Cancer
  • Ovarian Cancer
  • Pancreatic Cancer
  • Penile Cancer
  • Primary Bone Cancer
  • Primary Liver Cancer
  • Prostate Cancer
  • Retinoblastoma
  • Rhabdomyosarcoma
  • Scrotal Lumps, Pain and Swelling
  • Skin Cancer (Melanoma)
  • Skin Cancer (Non-Melanoma)
  • Stomach Cancer (Gastric Cancer)
  • Testicular Cancer
  • Throat Cancer (Laryngeal Cancer)
  • Thyroid Cancer
  • Vulval Cancer
  • Wilms’ Tumour

What are tumours?

A tumour is a lump or growth of tissue made up from abnormal cells. Tumours are divided into two types: benign and malignant.

Non-cancerous (benign) tumours

These may form in various parts of the body. Benign tumours grow slowly and do not spread or invade other tissues. They are not cancerous and are not usually life-threatening. They often do no harm if they are left alone. However, some benign tumours can cause problems. For example, some grow quite large and may cause local pressure symptoms, or look unsightly. Also, some benign tumours that arise from cells in hormone glands can make too much hormone, which can cause unwanted effects.

Cancerous (malignant) tumours

Malignant tumours tend to grow quite quickly, and invade into nearby tissues and organs, which can cause damage. Tumours normally develop in one original site – the primary tumour. Malignant tumours may also spread to other parts of the body to form secondary tumours (metastases). This happens if some cells break off from the primary tumour and are carried in the bloodstream or lymph channels to other parts of the body. These secondary tumours may then grow, invade and damage nearby tissues, and spread again.

Note: not all cancers form solid tumours. For example, in cancer of the blood cells (leukaemia) many abnormal blood cells are made in the bone marrow and circulate in the bloodstream.

What is carcinoma in situ?

A carcinoma in situ is the very early stage of a cancer when the abnormal cancer cells are confined to their original site. At this stage no tumour has grown and no cancer cells have spread. It may be that many cancers remain at this dormant stage for months, or even years, before they start to grow and spread into a proper cancer. This may be because the cells of the carcinoma in situ do not have the ability to stimulate new blood vessels. If they cannot stimulate new blood vessels to grow then the cancer itself cannot grow or spread.

It is thought that one or more of the cells in a carcinoma in situ may then mutate after some time (some genes may be altered). This then gives them the ability to make chemicals to stimulate new blood vessels. The cancer then grows and spreads as described above.

A carcinoma in situ contains only a small number of cells and is usually too small to be detected by scans or X-rays. However, some screening tests may detect a carcinoma in situ. For example, some cells from an abnormal cervical screening test, looked at under the microscope, may show carcinoma in situ. These cells can then be destroyed by treatment which prevents cancer from developing. Sometimes a small sample (a biopsy) taken from a part of the body may show a carcinoma in situ.

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