Lung cancer

[Luis Fok]

Lung cancer is the leading cause of cancer death in both men and women. About 85% of cases are related to cigarette smoking.

One common symptom is a persistent cough or a change in the character of a chronic cough.
Chest x-rays can detect most lung cancers, but other additional imaging tests and biopsies are needed to confirm the diagnosis.
Surgery, chemotherapy, targeted agents, immunotherapy, and radiation therapy may all be used to treat lung cancer.

In 2020, an estimated 228,820 new cases of lung cancer will be diagnosed in the US (112,520 in women and 116,300 in men), and 135,720 people will die from the disease. The incidence of lung cancer has been declining in men over the past 2 decades and has started to decline in women. These trends reflect a decrease in the number of smokers over the last 30 years.
Primary lung cancer is cancer that originates from lung cells. Primary lung cancer can start in the airways that branch off the trachea to supply the lungs (the bronchi) or in the small air sacs of the lung (the alveoli).
Metastatic lung cancer is cancer that has spread to the lung from other parts of the body (most commonly from the breasts, colon, prostate, kidneys, thyroid gland, stomach, cervix, rectum, testes, bones, or skin).
There are two main categories of primary lung cancer:

Non–small cell lung cancer: About 85% of lung cancers are in this category. This cancer grows more slowly than small cell lung cancer. Nevertheless, by the time about 40% of people are diagnosed, the cancer has spread to other parts of the body outside of the chest. The most common types of non–small cell lung cancer are squamous cell carcinoma, adenocarcinoma, and large cell carcinoma.
Small cell lung cancer: Sometimes called oat cell carcinoma, this cancer accounts for about 15% of all lung cancers. It is very aggressive and spreads quickly. By the time that most people are diagnosed, the cancer has spread to other parts of the body.

Rare lung cancers include

Bronchial carcinoid tumors (which may also be non-cancerous)
Bronchial gland carcinomas
Lymphomas (cancers of the blood system)
Mesothelioma (due to asbestos exposure)