It is estimated that 85% of cases of lung cancer are non small cell lung cancer (NSCLC). It affects the cells that line the airways and the lungs, as well as spreading to other parts of the body. There are three main subtypes of NSCLC: adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Each subtype has different characteristics and treatment options.
Causes
Nearly 80% to 90% of NSCLC cases are related to smoking or exposure to secondhand smoke. Other risk factors for NSCLC include:
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The presence of radon, asbestos, air pollution, or other carcinogens
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Lung cancer in the family
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Age
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Diseases of the lungs, such as chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis
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Mutations in genes such as EGFR, ALK, or KRAS
Symptoms
It is common for NSCLC to cause no symptoms until it is advanced. Some common symptoms include:
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Coughing that produces blood
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Pain or discomfort in the chest
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Wheezing or shortness of breath
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Changes in voice or hoarseness
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Loss of appetite or weight loss
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Weakness or fatigue
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Bronchitis and pneumonia are recurrent infections
Additional symptoms may occur if NSCLC spreads to other organs, such as:
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Fractures or pain in the bones
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Seizures or headaches
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Yellowing of the skin and eyes is called jaundice
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Face, neck, or arm swelling
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Bloating or pain in the abdomen
Diagnosis
An NSCLC diagnosis is made by performing a physical examination and asking about the patient's medical history and symptoms. The doctor will also order tests to confirm the diagnosis and determine the stage and subtype of the cancer. These tests include:
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A chest X-ray can reveal the size and location of lung tumors
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The CT scan, MRI, or PET scan can provide more detailed images of the lungs and other organs and show whether the cancer has spread
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Cancer cells can be found in sputum cytology, which examines mucus coughed up from the lungs
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In a biopsy, tissue is removed from the lung or other sites for microscopic examination
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A molecular test can identify specific genetic mutations or biomarkers in cancer cells that may guide treatment.
Treatment
Treatment options for NSCLC depend on the stage, subtype, and molecular profile of the cancer, as well as the patient's overall health and preferences.
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Surgery is usually performed for early-stage NSCLC that has not spread to other organs and can remove the tumor and some surrounding tissue from the lung. Depending on the size and location of the tumor, surgery may include lobectomy, pneumonectomy, or wedge resection.
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Radiation therapy, which can use high-energy rays or particles to kill cancer cells or shrink tumors. Radiation therapy can be given externally or internally, and it can be used alone or in combination with other treatments. When NSCLC cannot be removed by surgery, radiation therapy can be used to relieve symptoms or prevent complications that result from it.
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Cancer cells can be killed or stopped from growing with chemotherapy, which can be given intravenously or orally. It can be used alone or in combination with other treatments. As well as reducing the risk of recurrence after surgery or radiation therapy, chemotherapy can be used for NSCLC that has spread to other organs.
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Drugs that target specific molecules or pathways involved in the growth and survival of cancer cells can be used as targeted therapy. If a patient has NSCLC with certain genetic mutations or biomarkers, such as EGFR, ALK, or ROS1, targeted therapy can be given intravenously or orally. This type of therapy can also be used as part of other treatments.
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Drugs that stimulate the immune system to recognize and attack cancer cells are called immunotherapy. They can be given intravenously or subcutaneously, and can be combined with other treatments. When NSCLC has certain biomarkers, such as PD-L1, or has not responded to other treatments, immunotherapy can be used.
Prevention
Smoking and exposure to tobacco smoke are the best ways to prevent NSCLC. Other preventative measures include:
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Keeping radon, asbestos, air pollution, and other carcinogens at a minimum
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Eating fruits, vegetables, whole grains, and lean proteins as part of a healthy diet
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Regular exercise and maintaining a healthy weight
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Regular lung cancer screenings, especially if you are at high risk
