Lung cancer has emerged as the leading killer of men and women with invasive cancer, affecting husbands and wives, friends and neighbors, and causing suffering for many families. In the United States, lung cancer overtook breast cancer as the leading cause of cancer deaths in women in 1987. Lung cancer deaths account for a quarter of all American cancer deaths, killing more people every year than prostate, breast, and colon cancer combined. Nearly 160,000 Americans died from lung cancer in 2017.

The exact cause of lung cancer is still being investigated. Certain risk factors have been shown to play a part in causing cells to become cancerous. Risk factors for lung cancer include smoking, exposure to air pollution, and genetics.

Does Smoking Cause Lung Cancer?

The major cause of lung cancer in men and women is cigarette smoking. In 1876, a machine was invented to make rolled-up cigarettes and thus provided cheap tobacco products to almost anyone. Before that time, lung cancer was relatively rare. After the invention of cigarette mass production, smoking dramatically increased, and so did lung cancer. Currently, about 90% of all lung cancers are related to smoking. Radon gas, pollution, toxins, and other factors contribute to the remaining 10%.

Cigarettes and cigarette smoke contain over 70 cancer-causing chemicals (carcinogens). Some of the carcinogens found in cigarette smoke include:

• Lead (a highly poisonous metal)

• Arsenic (an insecticide)

• Cadmium (a battery component)

• Isoprene (used to make synthetic rubber)

• Benzene (a gasoline additive)

Cigar smoke is heavy in tobacco-specific nitrosamines (TSNAs), which are considered particularly cancerous.

Lung Cancer and Cilia

Cigarette smoke damages and sometimes kills hair-like projections on airway cells. These are known as cilia. The cilia normally sweep out toxins, carcinogens, viruses, and bacteria. When cilia are damaged or destroyed by smoke, all of these items may accumulate in the lungs and may cause problems such as infections and lung cancer.