Lung Cancer

Lung cancer can originate from a variety of cell types within the lungs and is differentiated into non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). NSCLC accounts for 85% to 90% of lung cancers and includes squamous cell lung cancer, adenocarcinoma, and large cell carcinoma. SCLC grows more quickly and has often metastasized by the time of diagnosis.¹

Lung cancer is the second most common cancer and the leading cause of cancer death in both men and women (25%). It is the most preventable cancer in the world.² Smoking is the primary cause of lung cancer while radon gas exposure is the second. Environmental carcinogen exposure to asbestos, arsenic, chromium, nickel, tar, mineral oils, mustard gas, silica, diesel exhaust, ionizing radiation, and bis(chloromethyl) ether also increase risk.³

Symptoms of lung cancer include a cough that is persistent or worsens, coughing up blood, shortness of breath or wheezing, chronic pneumonia or bronchitis, weight loss, and fatigue. Diagnosis is confirmed through history, X-ray, computerized tomography (CT), sputum, and biopsy. Lung cancer is primarily treated with surgery, and at times with chemotherapy and radiation depending on the type of tumor and extent of metastases.¹

Smoking

Tobacco use accounts for 30% of all cancer deaths, causing 87% of lung cancer deaths in men and 70% of lung cancer deaths in women. Each year, over 7,000 nonsmoking adults die of lung cancer as a result of breathing secondhand smoke.² Squamous cell carcinoma and SCLC are most commonly associated with smoking. The risk declines with smoking cessation, reaching the risk level of nonsmokers after 20 to 25 years. The major lung carcinogens found in tobacco smoke are polycyclic aromatic hydrocarbons. Additionally, nicotine induces lung cancer cell line proliferation, promotes angiogenesis, and promotes resistance to apoptosis induced by chemotherapy.⁴

The United States Preventive Services Task Force (USPSTF) recommends annual lung cancer screening with a low-dose CT scan in adults aged 55 to 74 years who have a 30-pack per year smoking history and who currently smoke or have quit within the past 15 years. Screening should be discontinued once a person has not smoked for 15 years or develops a health problem that substantially limits life expectancy or the ability or willingness to have curative lung surgery.