Last month, the Centers for Medicare and Medicaid Services (CMS) announced that Medicare will be covering CT lung screening for high-risk individuals, defined as those ages 55 to 74, who have at least a 30 pack-year history of smoking and who are either current smokers or have quit in the last 15 years. Although lung cancer is only the third most common cancer among Americas, it is the leading cause of cancer death, resulting in more deaths each year than breast cancer and prostate cancer combined, points out Jane Brody in the New York Times Science Section.
According to the American Cancer Society, more than 159,000 Americans will die this year from lung cancer, largely due to the fact that over 70 percent of lung cancers are diagnosed in advanced stages. Only 16 percent of those diagnosed with lung cancer are alive five years after the diagnosis. Screening could potentially change this picture. A study published in the New England Journal of Medicine from the National Lung Screening Trial (NLST) showed convincingly that annual screening with low-dose (or spiral) CT chest scans reduced mortality from lung cancer in heavy smokers and former smokers, preventing three lung cancer deaths for every 1000 people screened.
However, according to Dr. Peter B. Bach of Memorial Sloan-Kettering Cancer Center and Dr. Michael K. Gould of Kaiser Permanente Southern California, For the benefits shown in the trial to be fully realized and for those benefits to outweigh potentially serious risks, screening would have to be limited to people at high risk of developing lung cancer. This would prevent 15 times as many lung cancer deaths as screening those at low risk of developing the disease. They also point out that screening should only be done using up-to-date equipment and by those who know how to interpret results.
However, Brody also points out the complications that arise from screening such as false positives. In the study referenced above, complications occurred in 33 out of every 10,000 persons mainly due to procedures done to determine whether nodules seen on the CT scan were cancerous. Additionally, follow-up tests often lead to discovering other potential problems that lead to more tests.
Perhaps the most important point is this: Every screening program should offer help for smoking cessation. Stopping smoking is far more important than screening, says Dr. Bach.