Secondhand Smoke and Lung Cancer Risk and Screening
I am a 37-year-old female non-smoker. Although I have never smoked, both my father (at age 51) and paternal grandmother (at age 72) died of lung cancer and smoked heavily. I was exposed to years of second-hand smoke, as I lived in the same house as my father for 12 years and he averaged 3-5 packs of cigarettes a day. Am I at high risk for developing lung cancer, and are there any screening tests, such as CT scans, that I should be getting as a precaution?
Anil Vachani, MD, Pulmonologist at Penn Medicine, responds:
The risk of developing lung cancer is highest in smokers and ex-smokers. This risk increases with increasing number of packs per day and greater total number of years one has smoked. Though the risk declines after tobacco cessation, it is still significantly higher compared to someone who is a life-long non-smoker. Approximately 85-90% of all lung cancer cases occur in current or former smokers. Exposure to secondhand smoke does raise the chance of lung cancer. However, this increase is !0only!1 about 20% greater than the risk of a non-smoker who has not been exposed to secondhand smoke. Therefore, your overall risk is still very low.
Unfortunately, there are no approved methods for lung cancer screening, and no medical organizations currently recommend screening for lung cancer in patients who do not have a personal significant history of smoking. CT screening in patients with heavy smoking histories can detect smaller tumors than x-rays can, and CT scans can actually improve overall survival, likely through earlier detection at which time lung cancer treatments are more effective. As with any screening test, however, there is always a possibility of the test detecting a lung abnormality that is not cancer. In fact, the majority of lung nodules found on screening CT scans are benign, but work-up for these nodules, including biopsies, can be associated with morbidity. Without you having a personal history of smoking, the risks of screening likely outweigh the benefits in your case.