Most common lung cancer

What are the types of lung cancer?

Lung cancers are broadly classified into two types: small cell lung cancers (SCLC) and non-small cell lung cancers (NSCLC). This classification is based upon the microscopic appearance of the tumor cells. These two types of cancers grow, spread, and are treated in different ways, so making a distinction between these two types is important.

SCLC comprises about 10%-15% of lung cancers. This type of lung cancer is the most aggressive and rapidly growing of all the types. SCLC is strongly related to cigarette smoking. SCLCs metastasize rapidly to many sites within the body and are most often discovered after they have spread extensively.

NSCLC is the most common lung cancer, accounting for about 85% of all cases. NSCLC has three main types designated by the type of cells found in the tumor. They are:

  • Adenocarcinomas are the most common type of NSCLC in the U.S. and comprise up to 40% of lung cancer cases. While adenocarcinomas are associated with smoking like other lung cancers, this type is also seen in non-smokers — especially women — who develop lung cancer. Most adenocarcinomas arise in the outer, or peripheral, areas of the lungs. They also have a tendency to spread to the lymph nodes and beyond. Adenocarcinoma in situ (previously called bronchioloalveolar carcinoma) is a subtype of adenocarcinoma that frequently develops at multiple sites in the lungs and spreads along the preexisting alveolar walls. It may also look like pneumonia on a chest X-ray. It is increasing in frequency and is more common in women. People with this type of lung cancer tend to have a better prognosis than those with other types of lung cancer.
  • Squamous cell carcinomas were formerly more common than adenocarcinomas; today, they account for about 25% to 30% of all lung cancer cases. Also known as epidermoid carcinomas, squamous cell cancers arise most frequently in the central chest area in the bronchi. This type of lung cancer most often stays within the lung, spreads to lymph nodes, and grows quite large, forming a cavity.
  • Large cell carcinomas, sometimes referred to as undifferentiated carcinomas, are the least common type of NSCLC, accounting for 10%-15% of all lung cancers. This type of cancer has a high tendency to spread to the lymph nodes and distant sites.

Lung Cancer: Types of Lung Cancer

Different kinds of lung cancer may require distinct treatments.

There are two main types of lung cancer: non-small-cell lung cancer (NSCLC) and small cell lung cancer (SCLC). But several subtypes exist within and outside of these categories.

Additionally, some forms of lung cancer are referred to by different names.

Knowing the type of lung cancer you have can help you and your doctor develop effective treatment strategies.

Non-Small-Cell Lung Cancer (NSCLC) Types

NSCLC is the most common type of lung cancer, accounting for 80 to 85 percent of all cases.

There are three main subtypes of NSCLC, including adenocarcinomas, squamous cell carcinomas, and large cell carcinomas.


Adenocarcinomas represent about 40 percent of lung cancers.

This type of tumor starts in the cells that form the lining of the lungs.

Adenocarcinomas occur mostly in smokers, but they’re also the most common lung cancers to affect nonsmokers. This type of lung cancer is more prevalent in women and is most common in older individuals. Still, if you’re young and diagnosed with lung cancer, it’s most likely to be adenocarcinoma.

People with adenocarcinomas tend to have tumors that are caught earlier and grow more slowly, although this isn’t always the case.

There’s a rare subset of adenocarcinoma that begins in the alveoli and usually has a better prognosis. This type is called adenocarcinoma in situ (AIS) and was referred to as bronchioloalveolar carcinoma (BAS) in the past. These tumors are usually small — less than 2 inches — and account for about 3 percent of lung cancer diagnoses.

Similar to AIS is a classification of adenocarcinoma called minimally invasive adenocarcinoma (MIA), which are also small tumors, though they harbor a small amount of tissue that appears to be invading the normal surrounding lung. Both of these cancers are considered cured in nearly all cases by surgical resection alone.

Squamous Cell Carcinoma

Between 25 and 30 percent of lung cancers are squamous cell carcinomas.

This type of lung cancer, which is sometimes also called epidermoid carcinoma, starts in the flat cells that line the inside of the airways.

Squamous cell carcinomas are linked to smoking and can be found in the center part of the lungs.

Large cell carcinomas

Large cell carcinomas make up about 10 to 15 percent of lung cancers.

This type of cancer can show up in any part of the lung. It usually grows and spreads rapidly, which makes treatment a challenge.

A subtype of large cell carcinoma, known as large cell neuroendocrine carcinoma, is a fast-growing, aggressive type of cancer.

Other subtypes of NSCLC

Other subtypes of NSCLC include adenosquamous carcinoma and sarcomatoid carcinoma. These are much less common forms of lung cancer.

Small Cell Lung Cancer (SCLC)

SCLC, which is sometimes also called “oat cell carcinoma,” accounts for about 15 to 20 percent of lung cancer cases.

This form of lung cancer is a type of neuroendocrine tumor that contains cells that are smaller in size.

It’s typically aggressive and fast growing.

Other Types of Lung Cancer

Other types of tumors can occur in the lungs, including:

Lung Carcinoid Tumors These tumors typically grow slowly. They account for fewer than 5 percent of lung tumors.

Mesothelioma This type of cancer can start in the lungs, abdomen, heart, or chest. It is most commonly found in the lining of the lung, and this is linked to exposure to the chemical asbestos.

Rare Tumors Other tumors, like adenoid cystic carcinomas, sarcomas, lymphomas, and hamartomas (benign lung tumors), are rare but can occur in the lungs.

Cancers That Spread to the Lungs Cancer that starts in another organ can metastasize to the lungs, although this isn’t considered lung cancer. For instance, a tumor that starts in the liver but spreads to the lungs is still considered a liver tumor and is treated as one would treat a liver tumor.

Bronchogenic Carcinoma

In the past, the term “bronchogenic carcinoma” was used to describe lung cancers that started in the bronchi, or the large airways of the lungs.

Today, the name is generally used to refer to all types of lung cancers. In other words, bronchogenic carcinoma is just another way of saying “lung cancer.”

Lung Cancer Types

Chest Wall Tumors

Chest wall tumors are rare. Like other cancers, tumors found in the chest wall may be malignant or benign. Malignant tumors must be treated. Benign tumors will be treated depending on where they are located and the symptoms they cause. If a tumor presses against a lung so that a patient can’t breathe, for example, then it must be treated.

Types of Chest Wall Tumors

Tumors found in the chest wall are also categorized by whether they are primary tumors (starting in the chest wall) or metastatic tumors (spread to the chest wall from cancer that started elsewhere, such as in the breast). All metastatic tumors are malignant. In children, most chest wall tumors are primary, while they are more often metastatic in adults. Primary tumors start in the bones or muscles located in the chest wall.

Sarcomas — tumors that start in bone or muscle tissue, or more rarely in other types of tissue — are the most common type of primary tumor found in the chest wall.

Metastasized Cancer

Some cancers in the lung are the result of pulmonary metastasis — cancer that began in another part of the body and spread to the lung through the lymphatic system or bloodstream. Almost any cancer can metastasize to the lung. Some cancers that often spread to the lung are:

  • Bladder cancer

  • Breast cancer

  • Colon cancer

  • Kidney cancer

  • Neuroblastoma

  • Prostate cancer

  • Sarcoma

  • Wilms’ tumor

Rare Cancer Types

Carcinoid Tumors

Carcinoid tumors are rare cancers that most often appear in the stomach or intestines. However, they sometimes start in the lung. Carcinoid tumors can be classified as either typical or atypical.

  • Typical carcinoids grow slowly and don’t often spread beyond the lungs. Nine out of 10 lung carcinoids are typical carcinoids.

  • Atypical carcinoids grow faster and are slightly more likely to spread outside the lungs.

Carcinoid tumors are also sometimes categorized by where they start in the lung:

  • Central carcinoids form in the bronchi, which are the large airways located near the center of the lungs. Most lung carcinoid tumors start there. These carcinoids are almost always typical carcinoids.

  • Peripheral carcinoids develop in the smaller airways on the edges of the lungs and they too are almost always typical carcinoids.

Lung carcinoid tumors are most often treated by surgery. Chemotherapy and radiation therapy may be used as adjunct therapies or if surgery is not possible.

Mediastinal Tumors

Mediastinal tumors are rare tumors that develop in the mediastinum, the area of the chest that separates the lungs. It is surrounded by the breastbone in front and spine in the back.

They can be benign or cancerous, forming from any tissue that exists or passes through the chest cavity. Most mediastinal tumors in children are benign while many mediastinal tumors in adults are cancerous. Because they are located in the chest cavity where the heart and major arteries are or near the spinal cord in back, both benign and malignant tumors must be treated.

There are several types of mediastinal tumors:

Germ cell tumors: These cancers are very treatable and often curable. They develop from reproductive cells and are more often found in the reproductive systems of both men and women. When found outside the reproductive system, they may also be called extragonadal germ cell tumors. How these cells move from the reproductive system to the mediastinum is not currently known.

Lymphomas: These malignant tumors start in the lymphatic system and include Hodgkin’s lymphoma and non-Hodgkin’s lymphoma. The lymphatic system is a complex network of capillaries, thin vessels, valves, ducts, nodes and organs that helps to protect and maintain the fluid environment of the body by filtering and draining lymph. In rare case, lymphoma can originate in the lungs.

Teratomas: These malignant tumors are made of cysts that contain one or more layers of embryonic cells. The layers are called ectoderms, mesoderms and endoderms. A rare cancer, teratomas occur most often in young men in their twenties and thirties. The tumors are most often located in the chest area. By the time the cancer is diagnosed, they have often spread. A number of other cancers are often associated with these tumors, including:

  • Acute myelogenous leukemia (AML)

  • Embryonal rhabdomyosarcoma (ERMS)

  • Malignant histiocytosis

  • Myelodysplasia (MDS)

  • Small cell undifferentiated carcinoma

Thymomas: Thymomas and thymic carcinoma are rare cancers in which cancerous cells form on the outside of the thymus, a small organ in the upper chest that makes white blood cells. Thymomas are rarely malignant, grow slowly and don’t often spread beyond the thymus. Thymoma is linked with myasthenia gravis and other autoimmune diseases (diseases that cause the immune system to attack healthy cells and tissue).

Thymic carcinomas grow more quickly and have usually spread by the time the cancer is diagnosed. People with thymoma often have autoimmune diseases as well.

  • Medications can be used to stop a cough, open closed airways, or reduce bronchial secretions.

  • Prednisone or methylprednisolone (A-Methapred, Depo-Medrol, Medrol, Solu-Medrol) can reduce inflammation caused by lung cancer or radiation therapy and improve breathing.

  • Extra oxygen from small, portable tanks can help make up for the lung’s reduced ability to extract oxygen from the air.

  • Medications are available to strengthen bones, lessen bone pain, and help prevent future bone metastases.

  • Appetite stimulants and nutritional supplements can improve appetite and reduce weight loss.

  • Before treatment begins, talk with your doctor about the goals of each treatment in the treatment plan. You should also talk about the possible side effects of the specific treatment plan and palliative care options.

    During treatment, your health care team may ask you to answer questions about your symptoms and side effects and to describe each problem. Be sure to tell the health care team if you are experiencing a problem. This helps the health care team treat any symptoms and side effects as quickly as possible. It can also help prevent more serious problems in the future.

    Learn more about the importance of tracking side effects in another part of this guide. Learn more about palliative care in a separate section of this website.

    Treatment of NSCLC by stage

    Stage I and II NSCLC

    In general, stage I and stage II NSCLC are treated with surgery. Surgeons cure many people with an operation.
    Before or after surgery, a patient may also meet with a medical oncologist. Some patients with large tumors or signs that the tumor has spread to the lymph nodes may benefit from chemotherapy. Chemotherapy may be given before the surgery, called neoadjuvant chemotherapy or induction chemotherapy. Chemotherapy may also be given after surgery, called adjuvant chemotherapy, to reduce the chance that the cancer will return.

    Adjuvant chemotherapy with cisplatin is not recommended for patients with stage IA NSCLC that was completely removed with surgery. Patients with stage IB lung cancers should talk with their doctors about whether chemotherapy is right for them after surgery. Adjuvant cisplatin-based chemotherapy is recommended for patients with stage II NSCLC that has been completely removed with surgery. Patients with stage II NSCLC should talk with their doctor about whether this treatment is right for them.

    Stage III NSCLC

    More than 30,000 people are diagnosed with stage III NSCLC every year, and there is no single best treatment for all of these patients. Treatment options depend on the size and location of the tumor and the lymph nodes that are involved. The options generally include:

    • Radiation therapy

    • Chemotherapy

    • Immunotherapy

    • Surgery

    In general, people with stage III NSCLC receive 3 different types of treatment. A combination of chemotherapy and radiation therapy followed by immunotherapy is usually recommended for NSCLC that cannot be removed with surgery. Chemotherapy and radiation therapy may be given together, which is called concurrent chemoradiotherapy. Or, they may be given one after the other, called sequential chemoradiotherapy.

    Adjuvant cisplatin-based chemotherapy is recommended for people with stage IIIA lung cancers that have been completely removed with surgery. Patients should talk with their doctor about the best treatment options for them.

    Surgery may be an option after initial chemotherapy or chemotherapy with radiation therapy. Sometimes, surgery may be the first treatment, particularly when cancer is found in the lymph nodes unexpectedly after a person has originally been diagnosed with stage I or stage II cancer. If this occurs, surgery is generally followed by chemotherapy and often radiation therapy.

    Metastatic or stage IV NSCLC

    If cancer spreads to another part in the body from where it started, doctors call it metastatic cancer. If this happens, it is a good idea to talk with doctors who have experience in treating it. Doctors can have different opinions about the best standard treatment plan. Clinical trials might also be an option. Learn more about getting a second opinion before starting treatment, so you are comfortable with your chosen treatment plan.

    Patients with stage IV NSCLC typically do not receive surgery or radiation therapy as the main treatment. Occasionally, doctors may recommend surgery for a metastasis in the brain or adrenal gland if that is the only place the cancer has spread. People with stage IV disease have a very high risk of the cancer spreading or growing in another location. Most patients with this stage of NSCLC receive systemic therapies, such as chemotherapy, targeted therapy, or immunotherapy. Palliative care will also be important to help relieve symptoms and side effects.

    Systemic therapy for metastatic or stage IV NSCLC (updated 01/2020)

    The goals of systemic therapies are to shrink the cancer, relieve discomfort caused by the cancer, prevent the cancer from spreading further, and lengthen a patient’s life. These treatments can occasionally make metastatic lung cancer disappear. However, doctors know from experience that the cancer will usually return. Therefore, patients with stage IV disease are never considered “cured” of their cancer no matter how well treatment works. Treatment often continues as long as it is controlling the cancer’s growth. Systemic therapy and palliative care have been proven to improve both length and quality of life for patients with stage IV NSCLC. If the cancer worsens or causes too many severe side effects, the treatment may be stopped. Patients would continue to receive palliative care and may be offered treatment in a clinical trial.

    The first drug or combination of drugs a patient takes is called “first-line” treatment, which may be followed by “second-line” and “third-line” treatment. No specific treatment or combination of treatments works for every patient. If the first-line treatment causes too many or dangerous side effects, does not appear to be working, or stops working, the doctor may recommend a change in treatment. ASCO’s recommendations for systemic therapies for NSCLC are included below. All patients should also receive palliative care.

    • First-line treatment. First-line systemic therapy for NSCLC often depends on the genetic changes found in the tumor.

      • For patients with tumors that do not have changes in the EGFR or ALK genes, the options include:

        • For people with non-squamous cell carcinoma with high PD-L1 expression: Pembrolizumab alone; a combination of pembrolizumab, carboplatin, and pemetrexed; a combination of atezolizumab, carboplatin, paclitaxel, and bevacizumab; or a combination of atezolizumab, carboplatin, and nab-paclitaxel.

        • For people with non-squamous cell carcinoma and low PD-L1 expression: Pembrolizumab combined with carboplatin and pemetrexed; a combination of atezolizumab, carboplatin, paclitaxel, and bevacizumab; or a combination of atezolizumab, carboplatin, and nab-paclitaxel. In those who cannot receive immunotherapy, a combination of 2 chemotherapy drugs is recommended. Pembrolizumab alone may be recommended for people who cannot receive a combination of pembrolizumab with a platinum chemotherapy.

        • For people with non-squamous cell carcinoma and no PD-L1 expression: Pembrolizumab combined with carboplatin and pemetrexed; a combination of atezolizumab, carboplatin, paclitaxel, and bevacizumab; or a combination of atezolizumab, carboplatin, and nab-paclitaxel. In those who cannot receive immunotherapy, a combination of 2 chemotherapy drugs is recommended.

        • For people with squamous cell carcinoma and high PD-L1 expression: Pembrolizumab alone or a combination of pembrolizumab, carboplatin, and paclitaxel or nab-paclitaxel.

        • For people with squamous cell carcinoma and low PD-L1 expression: A combination of pembrolizumab, carboplatin, and paclitaxel or nab-paclitaxel should be recommended when it is possible. In those who cannot receive immunotherapy, a combination of 2 chemotherapy drugs is recommended. Pembrolizumab alone may be recommended for people who cannot receive chemotherapy.

        • For people with squamous cell carcinoma and no PD-L1 expression: A combination of pembrolizumab, carboplatin, and paclitaxel or nab-paclitaxel should be recommended when it is possible. In those who cannot receive immunotherapy, a combination of 2 chemotherapy drugs is recommended.

      • For patients with tumors that have a genetic change on the EGFR gene, the following targeted therapies called TKIs may be options:

        • Afatinib

        • Dacomitinib

        • Erlotinib

        • Gefitinib

        • Osimertinib

      • For patients with tumors that have a genetic change on the ALK gene, targeted therapy options are alectinib, brigatinib, ceritinib, or crizotinib.

      • For patients with tumors that have a genetic change on the ROS1 gene, crizotinib is an option.

    • Second-line treatment. Second-line treatment for NSCLC depends on the gene mutations found in the tumor and the treatments patients have already received.

      • For patients with tumors that do not have changes in the EGFR, ALK, or ROS1 genes, the options include:

        • Nivolumab, pembrolizumab, or atezolizumab if they have a high level of PD-L1, received chemotherapy for first-line treatment, and have not received immunotherapy.

        • Nivolumab, atezolizumab, or chemotherapy if they have a low or unknown level of PD-L1 and have already received chemotherapy.

        • Chemotherapy for patients who have already received immunotherapy.

        • Docetaxel or docetaxel plus ramucirumab for patients who had severe side effects from immunotherapy.

        • Pemetrexed for patients with non-squamous cell carcinoma who did not receive it during first-line treatment.

      • For patients with tumors that have an EGFR gene mutation, the best treatment option depends on how the cancer worsened and whether the cancer developed a mutation called T790M, which makes it resistant to the TKI. Options include:

        • Osimertinib

        • Additional chemotherapy

        • Continued treatment with a TKI, plus surgery or radiation therapy to the areas where the cancer has spread

      • For patients with tumors that have an ALK gene mutation, options are:

        • Alectinib

        • Brigatinib

        • Ceritinib

        • Lorlatinib

      • For patients with tumors that have a ROS1 gene mutation, treatment options depend on the treatments received previously:

        • Crizotinib, if patients have not already received it

        • Chemotherapy, which may be given along with bevacizumab

      • For patients with tumors that have a BRAF mutation, options depend on whether they have already received immunotherapy:

        • Atezolizumab, nivolumab, or pembrolizumab for patients who have not already received any of these immunotherapies

        • Dabrafenib or a combination of dabrafenib and trametinib for patients who have already received immunotherapy

    • Third-line treatment. Third-line treatment for NSCLC is usually chemotherapy with pemetrexed or docetaxel.

    In all cases, patients and their doctors should discuss any reasons why some patients may not be able to receive immunotherapy.

    This information is based on several ASCO recommendations for the treatment of lung cancer. Read more about these recommendations on the ASCO website.

    Radiation therapy for brain metastases

    Chemotherapy is often not as effective as radiation therapy or surgery to treat NSCLC that has spread to the brain. For this reason, NSCLC that has spread to the brain is usually treated with radiation therapy, surgery, or both. This can cause side effects such as hair loss, fatigue, and redness of the scalp. With a small tumor, a type of radiation therapy called stereotactic radiosurgery can focus the radiation only on the tumor in the brain and lessen the side effects.

    Newer targeted therapies, such as osimertinib and alectinib, have shown that they can work well to treat brain metastases. In addition, immunotherapy may also be an option. This may allow many patients to have a systemic therapy for brain metastases and avoid the side effects that come from chemotherapy and radiation therapy to the brain.

    Palliative care

    As described above, palliative care will also be important to help relieve symptoms and side effects. Radiation therapy or surgery may also be used to treat metastases that are causing pain or other symptoms. Bone metastases that weaken major bones can be treated with surgery, and the bones can be reinforced using metal implants.

    For most people, a diagnosis of metastatic cancer is very stressful and, at times, difficult to bear. You and your family are encouraged to talk about how you feel with doctors, nurses, social workers, or other members of the health care team. It may also be helpful to talk with other patients, including through a support group.

    Remission and the chance of recurrence

    A remission is when cancer cannot be detected in the body and there are no symptoms. This may also be called having “no evidence of disease” or NED.

    A remission may be temporary or permanent. This uncertainty causes many people to worry that the cancer will come back. While many remissions are permanent, it is important to talk with your doctor about the possibility of the cancer returning. Understanding your risk of recurrence and the treatment options may help you feel more prepared if the cancer does return. Learn more about coping with the fear of recurrence.

    If the cancer returns after the original treatment, it is called recurrent cancer. It may come back in the same place (called a local recurrence), nearby (regional recurrence), or in another place (distant recurrence). Most often, when there is recurrence, it is stage IV disease.

    When this is a recurrence, a new cycle of testing will begin again to learn as much as possible about the recurrence. After this testing is done, you and your doctor will talk about the treatment options. Often the treatment plan will include the treatments described above such as surgery, chemotherapy, and radiation therapy, but they may be used in a different combination or given at a different pace. Your doctor may suggest clinical trials that are studying new ways to treat this type of recurrent cancer. Whichever treatment plan you choose, palliative care will be important for relieving symptoms and side effects.

    People with recurrent cancer often experience emotions such as disbelief or fear. You are encouraged to talk with the health care team about these feelings and ask about support services to help you cope. Learn more about dealing with cancer recurrence.

    If treatment does not work

    Recovery from cancer is not always possible. If the cancer cannot be cured or controlled, the disease may be called advanced or terminal.

    This diagnosis is stressful, and for many people, advanced cancer is difficult to discuss. However, it is important to have open and honest conversations with your health care team to express your feelings, preferences, and concerns. The health care team has special skills, experience, and knowledge to support patients and their families and is there to help. Making sure a person is physically comfortable, free from pain, and emotionally supported is extremely important.

    People who have advanced cancer and who are expected to live less than 6 months may want to consider hospice care. Hospice care is designed to provide the best possible quality of life for people who are near the end of life. You and your family are encouraged to talk with the health care team about hospice care options, which include hospice care at home, a special hospice center, or other health care locations. Nursing care and special equipment can make staying at home a workable option for many families. Learn more about advanced cancer care planning.

    After the death of a loved one, many people need support to help them cope with the loss. Learn more about grief and loss.

    The next section in this guide is About Clinical Trials. It offers more information about research studies that are focused on finding better ways to care for people with cancer. Use the menu to choose a different section to read in this guide.

    Types and Staging of Lung Cancer

    There are two major types of lung cancer, non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). Staging lung cancer is based on whether the cancer is local or has spread from the lungs to the lymph nodes or other organs. Because the lungs are large, tumors can grow in them for a long time before they are found. Even when symptoms—such as coughing and fatigue—do occur, people think they are due to other causes. For this reason, early-stage lung cancer (stages I and II) is difficult to detect.

    Non-Small Cell Lung Cancer

    Non-small cell lung cancer accounts for about 85 percent of lung cancers and includes:

    • Adenocarcinoma, the most common form of lung cancer in the United States among both men and women;
    • Squamous cell carcinoma, which accounts for 25 percent of all lung cancers;
    • Large cell carcinoma, which accounts for about 10 percent of NSCLC tumors.

    Stages of Non-Small Cell Lung Cancer

    Stage I: The cancer is located only in the lungs and has not spread to any lymph nodes.

    Stage II: The cancer is in the lung and nearby lymph nodes.

    Stage III: Cancer is found in the lung and in the lymph nodes in the middle of the chest, also described as locally advanced disease. Stage III has two subtypes:

    • If the cancer has spread only to lymph nodes on the same side of the chest where the cancer started, it is called stage IIIA.
    • If the cancer has spread to the lymph nodes on the opposite side of the chest, or above the collar bone, it is called stage IIIB.

    Stage IV: This is the most advanced stage of lung cancer, and is also described as advanced disease. This is when the cancer has spread to both lungs, to fluid in the area around the lungs, or to another part of the body, such as the liver or other organs.

    Small Cell Lung Cancer

    Small cell lung cancer accounts for the remaining 15 percent of lung cancers in the United States. They tend to grow more quickly than NSCLC tumors. Usually, SCLC is more responsive to chemotherapy than NSCLC.

    Stages of Small Cell Lung Cancer

    Limited stage: In this stage, cancer is found on one side of the chest, involving just one part of the lung and nearby lymph nodes.

    Extensive stage: In this stage, cancer has spread to other regions of the chest or other parts of the body.

    The American Joint Commission on Cancer implemented a more detailed staging system in which the stages of small cell lung cancer are described using Roman numerals and letters (for example, Stage IIA). This is the same method that is used for non-small cell lung cancer in describing the growth and spread of the cancer.

    Lung cancer

    Lung cancer types

    There are two main types of lung cancer: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). NSCLC accounts for nearly nine out of every 10 diagnoses and typically grows at a slower rate than SCLC.

    Small cell lung cancer is also known as “oat-cell” cancer because the cells look like oats under the microscope. It often starts in the bronchi, then quickly grows and spread to other parts of the body, including the lymph nodes. This type of lung cancer represents fewer than 20 percent of lung cancers and is typically caused by tobacco smoking.

    Small cell lung cancer is divided into two types, named for the kinds of cells found in the cancer and how the cells look when viewed under a microscope:

    • Small cell carcinoma (oat-cell cancer)
    • Combined small cell carcinoma

    Small cell lung cancer may be very aggressive and requires immediate treatment. Treatments for small cell lung cancer include:

    • Chemotherapy
    • Immunotherapy
    • Laser therapy
    • Radiation therapy
    • Surgery

    Non-small cell lung cancer

    Non-small cell lung cancer is the most common type of lung cancer. It accounts for nearly nine out of every 10 cases, and usually grows at a slower rate than SCLC. Most often, it develops slowly and causes few or no symptoms until it has advanced.

    There are three main types of non-small cell lung cancer:

    Adenocarcinoma of the lung: Lung adenocarcinoma is the most common form of lung cancer, accounting for 30 percent of all cases overall and about 40 percent of all non-small cell lung cancer occurrences. Adenocarcinomas are found in several common cancers, including breast, prostate and colorectal. Adenocarcinomas of the lung are found in the outer region of the lung, in glands that secrete mucus and help us breathe. Symptoms include coughing, hoarseness, weight loss and weakness.

    Learn more about adenocarcinoma of the lung

    Squamous cell: This type of lung cancer is found centrally in the lung, where the larger bronchi join the trachea to the lung, or in one of the main airway branches. Squamous cell lung cancer is responsible for about 30 percent of all non-small cell lung cancers, and is generally linked to smoking.

    Large-cell undifferentiated carcinoma: Large-cell undifferentiated carcinoma lung cancer grows and spreads quickly and can be found anywhere in the lung. This type of lung cancer usually accounts for 10 to 15 percent of all cases of NSCLC. Large-cell undifferentiated carcinoma tends to grow and spread quickly.

    Treatments for non-small cell lung cancer include:

    • Chemotherapy
    • Cryotherapy
    • Immunotherapy
    • Laser therapy
    • Photodynamic therapy
    • Radiation therapy
    • Surgery
    • Targeted therapy

    Lung nodules

    Lung nodules are small growths found inside the lung. Also called pulmonary nodules, lung nodules may develop no symptoms and often are found during tests to diagnose another condition. While most lung nodules are benign and are smaller than a golf ball, some may develop into cancerous tumors and grow over time, causing breathing problems and other symptoms. If a lung nodule is discovered during an imaging test, your doctor may want to monitor it to see whether it grows or changes shape.

    Getting a fast and accurate diagnosis is critical. Patients have more treatment options when the disease is diagnosed in its early stages than when it has advanced.

    Learn more about rapid lung-nodule diagnoses at CTCA Chicago and CTCA Tulsa

    Metastatic lung cancer

    Because symptoms do not always develop when lung cancer is present, it is common for the cancer to metastasize before it is diagnosed. Even though the cancer may have formed a tumor in a new location in the body,

    Learn more about metastatic lung cancer

    Rare forms of lung cancer

    Several types and subtypes of lung cancer are very rare. They include:

    • Adenosquamous carcinoma of the lung, a hybrid of adenocarcinoma and squamous cell lung cancer
    • Large cell neuroendocrine carcinoma, an aggressive subtype of non-small cell lung cancer
    • Salivary gland-type lung carcinoma, which is most often found in the central airways of the lungs
    • Lung carcinoids, a rare type of cancer often found in younger than average lung cancer patients
    • Mesothelioma, a rare type of cancer that develops in thin tissue called mesothelium, which lines the lungs and abdomen

    Other extremely rare forms of lung cancer include sarcomatoid carcinoma of the lung and malignant granular cell lung tumors.

    Our lung cancer centers

    At Cancer Treatment Centers of America® (CTCA), our lung cancer centers bring together multidisciplinary teams of doctors and other clinicians with the expertise to treat all stages of lung cancer. The experts at our lung cancer centers collaborate daily, delivering personalized treatments tailored to each patient’s goals and needs. Their singular focus on lung cancer enables our oncologists to stay up to date on new and emerging treatments and technologies, allowing us to help you make informed decisions about the options available to treat not just the disease but the side effects that may result.

    Types of Lung Cancer

    Lung cancer can be broken down into two main groups:
    Small cell lung cancer
    Non small cell lung cancer

    Although very imprecise there are some characteristics of each type of lung cancer that suggest their differentiation. Their treatments differ to some extent although the modalities of surgery, radiotherapy and chemotherapy can be applied in all types. Prognosis is determined most by the stage of the disease, although cell type has some influence.

    Small cell lung cancer

    The most important steps in the diagnosis and management of lung cancer is in defining the cell type and the stage of the disease. This entails defining the exact site and size of the tumour, and its local extent. A full appreciation of the involvement of local and distant lymph nodes is vital, as is the presence of distant spread to bone, liver and brain. This characterisation of the cancer dictates the form of treatment that will be offered more than anything else. The vigour with which a tumour can be treated depends upon the physical state of the patient hence an overall assessment of the patients’ health and condition is vital.

    Types of lung cancer – small cell lung cancer

    Small cell lung cancer is sometimes referred to as oat cell cancer due to the size and shape of the cancer cells. It is the least common of the two types of lung cancer accounting for approximately 12% of all lung cancer cases. Small cell lung cancer spreads quickly and hence patients are often in more advanced stages of lung cancer when diagnosed where surgery is no longer possible. This type of lung cancer is usually caused by smoking and it is rare for a non-smoker to develop small cell lung cancer. Surgical resection may be possible but treatment usually consists of chemotherapy which may be supplemented with radiotherapy. Occasionally the tumour may remain localised and surgery may have a role to play.

    Types of lung cancer – non small cell lung cancer

    The most common type of lung cancer is non small cell lung cancer and accounts for approximately 88% of all lung cancers. Non small cell lung cancer is grouped into three further types:

    • Squamous cell carcinoma – the most common type of lung cancer that is also known as epidermoid carcinoma. It usually occurs in the larger airways close to the centre of the lungs and is often caused by smoking. As a result, incidence of this form of lung cancer is now on the decline as smoking rates decline. This type of lung cancer tends to be slow growing and, because the tumours present in the airways, it can cause symptoms such as pneumonia and collapsed lung much earlier than other forms of lung cancer and can be detected at an earlier stage.
    • Adenocarcinoma – This type of lung cancer is the most common lung cancer found in women and the incidence is on the rise. It most commonly develops in the outer parts of the lungs. Because of this it presents few symptoms in the early stages of the disease making it difficult to detect. Adenocarcinoma may be found in non-smokers and is the most common type of lung cancer in Asians and people under 45.
    • Large cell carcinoma – Named as such due to the size of the cells in the tumour when viewed under a microscope. This type of lung cancer is most typically found in the outer regions of the lungs. It can be difficult to detect large cell lung cancer in the early stages as typical symptoms such as coughing up blood or a persistent cough may be less apparent. More obvious symptoms such as shortness of breath and chest pain (Pleurisy) can be caused by irritation of the lining of the lung (the pleura). The breathlessness may be caused by the production of excessive fluid between the pleural layers that line the lung. Pain in the chest may be worse when taking a deep breath. In some instances, large cell lung cancers can secrete a hormone like substance that can lead to paraneoplastic symptoms including breast swelling in men (see lung cancer symptoms for more information about paraneoplastic syndrome).

    Types of Lung Cancer – Mesothelioma

    Mesothelioma is a rare type of lung cancer but, unfortunately, incidence of this type of lung cancer is increasing. Most cases of mesothelioma are caused by exposure to asbestos in the workplace and, in most cases, development of the disease can take place many years after initial exposure. It is also possible to develop mesothelioma from radiation exposure and a virus called simian virus has also been linked to the disease.

    The mesothelium is a membrane that protects the lungs, heart and abdominal cavity and mesothelioma is a cancerous tumour that grows on the mesothelium. The symptoms are very similar to many other respiratory conditions so diagnosis can be difficult. A lung biopsy will be needed to confirm any initial diagnosis from X-Rays or other types of scan.

    Mesothelioma is one of the few cancers there are definitive prevention measures, e.g. wearing the correct protective equipment when working with asbestos and being aware of the dangers of asbestos in buildings.

    Less common types of lung cancer

    The types of lung cancer listed above are not complete. There are many other less common types of lung cancer including: pleomorphic, carcinoid tumour, salivary gland carcinoma and unclassified carcinoma.

    If you are worried about lung cancer, have lung cancer symptoms or think you may be at risk then please contact us to arrange a LungCheck. LungCheck, lung cancer screening involves an online risk assessment followed by a blood test.

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