Lung cancer screening and the national lung screening trial (NLST)

Lung cancer remains the most common cause of cancer-related deaths in the USA and worldwide. An estimated 220,000 new cases are diagnosed, while nearly 160,000 patients die from lung cancer each year in the USA alone, accounting for more cancer-related deaths than the next three most common cancers combined: colon, breast, and prostate [Jemal A et al., CA Cancer J Clin 61:69-9, 2011; Siegel R et al., CA Cancer J Clin 61:212-6, 2011]. In spite of major advances achieved in lung cancer diagnosis, medical, surgical treatment, and palliative care, the overall 5-year survival for lung cancer has not noticeably changed over the past 20 years and is estimated around 16 % [Goldstraw P et al., J Thorac Oncol 2:706-14, 2007]. These dismal statistics compare poorly with those of other common cancers such as colon, breast, and prostate cancers characterized by 5-year survival rates of 65 %, 88 % and 99 %, respectively. Among the many potential explanations advanced to explain such differences, the lack of effective screening for lung cancer is often contrasted to what are generally assumed and accepted screening strategies for those other malignancies. Lung cancer is in the majority of cases diagnosed at advanced stages, as symptoms prompt patients to seek medical attention, when curative therapeutic options are at best limited.