Lung Cancer Update

Randall Lanier, M.D., Pulmonologist

Randall Lanier, M.D., Pulmonologist

Lung cancer is a largely preventable medical condition. It is the most common cancer mortality in both men and women in the world. It is estimated in 2014 more than 224,000 cases will develop and have more than 159,000 deaths. This accounts for more deaths than the three most common cancer cases of colon, breast, and prostate combined. Lung cancer represents approximately 27 percent of all US cancer deaths. Lung cancer will be the largest cancer “killer” over the next 30 years. Twice as many people will be living with lung cancer in 2040 than in 2010. This is mainly due to longer life spans and cancer being more common as we age.

Fortunately for us, lung cancer death rates have begun to decline. Risk factors have not changed much over the years. Smoking is present in 90 percent of all lung cancers diagnosed. Other lung cancer risk factors include radiation, genetics, diet, HIV infection, emphysema, scarring of the lungs, and environmental toxins. Toxins include second hand smoke, asbestos, dust exposure, and radon which is radioactive gas produced by decay of uranium in soil.

Kentucky had the highest lung cancer death rate of any state in 2013. Kentucky also has the highest per capita tobacco use in the United States. Tobacco smoking is responsible for nearly 1 in 5 deaths in general. The smoking rate in the U.S. has dropped by half from 1965 to 2012. At the height of adult U.S. smoking, it was estimated that 42 percent of the population smoked. Now that estimate has dropped to 18.1 percent. However, in developing countries, tobacco consumption is rising at 3.4 percent per year as of 2002. Young adults are the most likely to start smoking with new onset of older smokers showing a marked decline.

Prognosis in lung cancer is generally poor because of not being able to diagnosis it due to lack of symptoms until it is in advanced stages. One year survival after diagnosis is at approximately 43 percent and five year survival is at 17 percent. Most cases are in patients greater than 65 years of age when diagnosed and has already been developing for several years.

As opposed to other cancers, where screening tools such as mammography, colonoscopy, and PSA levels are available, lung cancer screening has been slow to develop. Many earlier studies have shown that current lung cancer screening methods do not change mortality. Screenings have also led to over-diagnosis of lung cancer, particularly in Kentucky where lung scarring due to histoplasmosis, a fungal infection, is present.

The American Cancer Society published new guidelines in 2013 that recommend physicians discuss lung cancer screening in high risk individuals. High risk patients are identified as 55 to 74 years of age, good health, smoked the equivalent of 1 pack per day for 30 years, currently smoking, or who have quit within 15 years. It is recommended testing be completed with low dose computerized tomography (CT) in a facility experienced in lung cancer screening. It is also emphasized that screening is not a substitute for quitting smoking. Even though the American Cancer Society has developed these screening guidelines, all insurance companies are not reimbursing for screening as of yet. The most effective way to lower lung cancer risk is to stay away from tobacco.

References:

Midthun DE. Overview of the risk factors, pathology, and clinical manifestations of lung cancer. UpToDate. Jan 13, 2014.
Available at http://www.uptodate.com/contents/overview-of-the-risk-factors-pathology-and-clinical-manifestations-of-lung-cancer.

CA: A Cancer Journal for Clinicians. 2013; 63(1).

Lung Cancer Rates by State. Centers for Disease Control and Prevention. August 26, 2014.
Available at http://www.cdc.gov/cancer/lung/statistics/state.htm.