ABSTRACT
Lung cancer screening is the crucible where providing an expensive new service with the potential for harm in vast numbers of variably at-risk individuals collides with the consequences of the world’s most lethal cancer. With over 160 000 annual deaths, lung cancer accounts for 30% of cancer deaths in the USA. 1 Regional or distant metastatic spread is evident in at least threequarters of lung cancer cases at time of initial diagnosis resulting in a 5-year survival rate of 15%. For surgically resected cancer, the 5-year survival rate exceeds 60%. By comparison, localized breast and prostate cancer are detected at rates of 63 and 82%, so correspondingly their 5-year survival rates are much better at 87 and 98%, respectively. For women, there has been a 600% increase in the frequency in lung cancer over the last eighty years, and lung cancer death rates in United States women are the least favorable in the world. 2 Unlike cardiovascular disease, the risk of developing lung cancer remains elevated after smoking cessation. 3-5
Lung cancers are being diagnosed at least as frequently in the over 45 million former smokers as in current smokers, 3 and smoking cessation strategies are of no utility in the growing cohort of former smokers. The progress in cardiovascular disease has not been matched in lung cancer outcomes, so this cancer has recently emerged as the dominant cause of death in tobaccoexposed individuals. 6 Tobacco-related diseases are the leading cause of premature death and account for half of health-care costs in our society, so better approaches to lung cancer management are critical. 7
Promising reports with high-resolution computed tomography (CT) detection have renewed interest in early lung cancer screening. 4,8-11 No major lung cancer screening trial has been completed here in decades and the recent United States Preventive Services Task Force (USPSTF) analysis acknowledges the methodologic limitations of the previous chest X-ray screening trials. 12-14 Lingering debate about those earlier trials has fostered
concern about CT-based lung cancer detection being not only prohibitively expensive but possibly dangerous. 15-17 Against this charged back drop, it is timely to review the status of early lung cancer detection.
