Non-small cell lung cancer (NSCLC) is the most common type of malignancy (cancer) that affects the lungs, accounting for nearly 85% of lung cancers. While there are several types of non-small cell lung cancer, the three most common types are 1) adenocarcinoma, 2) squamous cell carcinoma, and 3) large cell carcinoma.  Adenocarcinoma occurs in the outer region of the lung and is the most common form of non-small cell lung cancer in the United States. Squamous cell carcinoma occurs in the center of the lung next to the bronchus (airway) and accounts for 25% of non-small cell cancers. Large cell carcinoma occurs in any part of the lung and accounts for 10% of non-small cell lung cancers. In addition to these three common types of non-small cell lung cancer, there are some less common types: pleomorphic (variable in size and shape), carcinoid tumor, salivary gland carcinoma, and unclassified carcinoma. Non-small lung cancer is classified in the following stages: Occult stage – Cancer is undetectable (hidden). Stage 0 – Carcinoma in situ, or the earliest stage at which non-small lung cancer can be detected. Stage I – Cancer is only in the lung with no spread. Stage II – Cancer is in the lung and close lymph nodes. Stage III – Cancer is in the lung and median (middle) chest lymph nodes, which is known as locally advanced lung cancer. This stage has two subtypes: 1) Stage IIIA – Cancer has only spread to same side chest lymph nodes; and 2) Stage IIIB – Cancer has spread to opposite side chest lymph nodes, or above the collarbone. Stage IV – Advanced lung cancer that has spread to both lungs, the fluid surrounding the lungs, or other organs or parts of the body.

Other names for non-small cell lung cancer include adenocarcinoma, carcinoid tumor, locally advanced lung cancer, large cell carcinoma, lung cancer, NSCLC, and squamous cell carcinoma.

Around 90% of non-small cell lung cancer cases are caused by smoking cigarettes, pipes, or cigars. As a smoker, whether currently or previously, the risk of developing non-small cell lung cancer is tied to the number of cigarettes or amount of tobacco smoked per day and for how many years. The earlier the start and the more amount smoked increases the risk of non-small cell lung cancer. Exposure to secondhand smoke also increases the risk of developing non-small cell lung cancer by 30-60%. However, it is possible to develop non-small cell cancer without having ever smoked due to other factors and genetics. While studies show that smoking marijuana may increase cancer cell growth, there has not been demonstrated a definitive link between smoking marijuana and developing non-small cell lung cancer. The risk of developing non-small cell lung cancer is further increased when smoking is combined with other risk factors. Other risk factors for developing non-small cell lung cancer include long-term exposure to high levels of air pollution, drinking water with high levels of arsenic, a history of radiation therapy to the lungs, exposure to atomic bomb radiation, radon in the home or workplace, imaging tests, and workplace exposure to cancer-causing chemicals and materials such as arsenic, asbestos, beryllium, chloride, chloromethyl ethers, chromium, coal products, diesel exhaust, formaldehyde, gasoline, mustard gas, nickel chromates, paints, pigments, soot, tar, uranium, and vinyl chloride. Additional risk factors include a family history of lung cancer (genetics), human immunodeficiency virus (HIV) infection, and taking beta carotene supplements. Finally, old age is the main risk for most cancers, as the chances of developing any cancer increase with age.

Early non-small cell lung cancer may not cause any symptoms and may be detected during medical examination for another condition. Symptoms of early non-small cell cancer include chronic cough, coughing up blood, shortness of breath, wheezing, fatigue, loss of appetite, unexplained weight loss, and chest pain. Symptoms that appear in the later stages of non-small cell lung cancer include hoarseness or changing voice, difficulty swallowing, eyelid drooping, facial swelling, nail abnormalities, bone, joint, and shoulder pain, and weakness.

There are several treatments available for non-small cell lung cancer; however, these treatments generally do not cure the cancer. The treatment depends on the stage of cancer and includes surgery, chemotherapy, targeted therapy, radiation therapy, laser therapy, photodynamic therapy, and immunotherapy. Surgery (resection) is one of the most common treatments for non-small cell lung cancer that has not yet spread to near lymph nodes. Types of surgery include lung lobectomy (removal of one of the lobes of the lung), wedge resection (removal of a small part of the lung), and pneumonectomy (removal of the entire lung). Chemotherapy is a mode of treatment that uses potent drugs designed to kill cancer cells, while stopping further cancer cells from growing. Chemotherapy alone is used for Stage IV non-small cell lung cancer when the cancer has spread outside the lung. Chemotherapy may also be used in combination with surgery or radiation. When used before these procedures, this form of chemotherapy is called neoadjuvant therapy. Chemotherapy may also be used after surgery to kill any lingering cancer in which case it is called adjuvant therapy. Chemotherapy is administered intravenously (IV) or in pill forms. Since undergoing chemotherapy can cause other symptoms (nausea and vomiting, fatigue, hair loss, and skin and nail changes), controlling these while preventing any complications is an essential part of lung cancer care. Radiation therapy is the use of X-Rays or other forms of radiation to kill cancer cells and is often combined with chemotherapy, especially if the lung cancer cannot be treated with surgery. Radiation therapy can help alleviate some of the symptoms caused by the cancer as well as relieve cancer pain when the cancer has spread. Like chemotherapy, radiation therapy can also cause further symptoms that are controlled as an essential part of non-small cell lung cancer care. Targeted therapy is a newer treatment that uses drugs designed to target molecules in or on cancer cells that control the growth and survival of the cancer, unlike chemotherapy and radiotherapy which do not distinguish between types of cells. Target therapy stops the cancer cells and their spread by disabling the mechanisms that allow them to survive. Some targeted therapies are erlotinib (Tarceva), for non-small cell lung cancers that contain epidermal growth factor receptor (EGFR); afatanib (Gilotrif) and Gefitinib (Iressa) for non-small cell lung cancers that have specific mutations of epidermal growth factor receptor; bevacizumab (Avastin), which, when combined with chemotherapy, stops the growth of blood supply to tumors and improves survival in the non-small cell cancer subtypes, adenocarcinoma and large cell carcinoma; crizotinib (Xalkori), for non-small cell carcinoma with the ALK gene mutation; and ceritinib (Zykadia) for non-small cell carcinoma with the ALK gene mutation when a patient cannot take crizotinib or it was ineffective. Other, less commonly used treatments such as laser therapy and photodynamic therapy are designed to help control the symptoms of non-small cell lung cancer. Laser therapy uses an intensely-focused small beam of light that burns cancer cells and kills them. Photodynamic therapy uses light that activates a drug in the body that kills the cancer cells. Immunotherapy is a new treatment for non-small cell lung cancer that uses a patient’s own immune system to treat the cancer. An immunotherapy treatment for metastatic (spreading) squamous non-small cell lung cancer is nivolumab (Opdivo) for lung cancer that has failed chemotherapy treatment. Nivolumab assists the body’s immune system in attacking the tumors. Pembrolizumab (Keytruda) is a newer immunotherapy for the treatment of advanced non-small cell lung cancer that works much like nivolumab. New treatments are currently being tested, such as chemoprevention, radiosensitizers, and new combinations of existing therapies. Clinical trials are also available for patients with non-small cell lung cancer to participate in before, during, or after starting treatment. Ongoing, long-term follow-up is part of the treatment for non-small cell lung cancer, as the cancer can reoccur after it has been treated.

There are a variety of support groups for individuals with non-small cell lung cancer: American Lung Association, Lung Cancer Support Groups - https://www.lung.org/lung-health-diseases/lung-disease-lookup/lung-cancer/patients/find-support/support-groups CancerCare.org  - https://www.cancercare.org/ Cancer Support Community: Non-Small Cell Lung Cancer - https://www.cancersupportcommunity.org/non-small-cell-lung-cancer

The outcome (prognosis) for non-small cell lung cancer varies and depends on several factors: 1) the type of non-small cell lung cancer (adenocarcinoma, squamous cell, large cell, or others); 2)  the stage of the cancer (the size of tumor and whether it has spread to the other lung or other parts of the body); 3) whether the cancer has gene mutations, such as epidermal growth receptor factor (EGFR) or anaplastic lymphoma kinase (ALK); 4) whether the cancer is accompanied by other symptoms, such as coughing or trouble breathing; and 5) the patient’s overall health.  Usually, non-small cell cancer grows slowly; however, in some cases, it can grow and spread rapidly, quickly causing death. Non-small cell lung cancer may also spread to other organs and parts of the body, including the liver, small intestine, bones, and brain. Chemotherapy has been proven to extend survival and improve the quality of life in patients with Stage IV non-small cell lung cancer. Overall cure rates are determined by the stage of disease and whether surgery is possible. Stages I and II non-small cell lung cancer have the highest cure and survival rates. Stage III non-small cell lung cancer can possibly be cured for some patients. Stage IV non-small cell lung cancer that has reoccurred can almost never be cured, in which case the goals of treatment are to improve quality of life and extend survival (palliative care). Even after successful treatment, non-small cell lung cancer can reoccur in other parts of the body, such as the brain.

Complications of non-small cell lung cancer include shortness of breath, fluid accumulation around the lung and in the chest (pleural effusion), coughing up blood (hemoptysis), pain, nausea, headaches, and the spread of cancer (metastasis) to other parts of the body through tissue, the lymph system, or blood, in which case the cancer is then not usually curable.

Call your doctor if you have symptoms of lung cancer, chronic cough, coughing up blood, shortness of breath, wheezing, fatigue, loss of appetite, unexplained weight loss, and chest pain, especially if you smoke.

The most effective ways for preventing non-small cell lung cancer are to quit smoking and avoid exposure to secondhand smoke. If you were previously a smoker, consider getting screened for lung cancer.