Lung cancer screening only recommended for high risk

DEAR DR. ROACH: For over six decades, I have lived with smokers. My parents smoked around their children inside our family home and inside the family car. Later, most of my siblings smoked. Family gatherings were always smoky affairs. I also married a smoker who smoked in the house until an infant grandson came to live with us. Though my husband started smoking outside, he continued to smoke in the car, sometimes with his window open. A collapsed lung during a biopsy finally led him to quit last year. He has COPD and is on oxygen full time.

Three maternal uncles died of lung cancer. All were heavy smokers who also worked in mines in their early adult years. My paternal grandmother, also a smoker, died of complications due to emphysema. With all that communicated to my physician, I am curious why he has never suggested a lung scan as a precaution, even though I have never smoked. It is my understanding that early stages of lung cancer are relatively asymptomatic and that breathing secondhand smoke can be as dangerous as smoking. What do you think? Would it be wise to request a precautionary scan even though I am in good health? Are there early symptoms I should know to look for?

— L.H. ANSWER: Lung cancer remains the single leading cause of cancer deaths, accounting for about a quarter of all cancer deaths. Early on, there are no signs nor symptoms, but coughing (especially producing blood), shortness of breath and chest discomfort are among the first signs that lung cancer is becoming more advanced. Smoking is by far the biggest risk factor for developing lung cancer. It is true that secondhand smoke increases the risk of developing lung cancer. When compared with nonsmokers who have never been exposed to secondhand smoke, nonsmokers who have a partner who smokes have a 25% to 35% increased risk of lung cancer. By contrast, a pack-and-a-half-a-day smoker has an 11,000% increased risk of lung cancer.

No studies have ever examined lung cancer screening in nonsmokers who were exposed to secondhand smoke. While it may seem there is no downside to getting the scan, there are at least two. The first is the time, expense and radiation dose of the scan. The second is that the scan can sometimes detect abnormalities that require further evaluation. These are usually proven to be of no clinical significance, but not before additional unnecessary tests and sometimes procedures have been done.

Because of the potential downsides of screening, lung cancer screening is recommended for people at higher risk for lung cancer: those who have smoked the equivalent of a pack a day for 15 years. In those people, the benefits of potentially finding a cancer early when it is curable outweigh the downsides.

Quitting smoking is the best way to reduce your own risk of lung cancer, and to reduce the risk of lung cancer, heart disease, COPD and other conditions in those you live with.