Diminished Disease-Free Survival After Lobectomy: Screening Implications

Current Controversies in Cardiothoracic Imaging: Low-dose Computerized Tomographic Overdiagnosis of Lung Cancer is Substantial; Its Consequences are Underappreciated-Point

Lung cancer seems an ideal screening candidate because of its frequency and lethality, its well-known risk factors, and because it can often be identified at a curable stage with noninvasive procedures. The lethality of clinically diagnosed lung cancers rendered the possibility of material overdiagnosis (OD) (by means of screening) implausible in the judgment of experienced clinicians. Increased experience with lung cancer screening trials, which showed an excess of cases in screened versus control cohorts, led to broader acceptance of its existence. The magnitude of OD and the appropriate methodology for its assessment are disputed. Overdiagnosed individuals experience substantial surgical mortality and their loss of pulmonary reserve leads, in many, to a material reduction in the duration and quality of life. To estimate the scale of computerized tomographic OD, taken as the excess of screen-identified cases versus unscreened controls, we pooled the long-term findings in the 3 reporting European trials comprising 10,675 subjects. There were 263 detected lung cancers in the low-dose, computerized tomographic-screened versus 153 in controls, a 42% excess.

Current Controversies in Cardiothoracic Imaging: Overdiagnosis at Lung Cancer Screening-Not So Bad After All-Counterpoint

Initially introduced into the medical literature in research publications from "Special Project #1" of the Council for Tobacco Research, the concept of overdiagnosed lung cancer (OD LC) has consistently served to misinform and confuse the medical community, contributing to interminable delays in implementation of population lung cancer screening. Estimates of overdiagnosis vary enormously (9.5% to 75%). Careful, judicious application of diagnostic algorithms and clinical practice guidelines prevents overtreatment of potentially OD LC and offers a safe and effective method to prevent tens of thousands of LC-related deaths. Speculative concern over potential OD should not further block availability of computed tomography screening to those at risk.

Five reasons for caution in advocating low-dose computerized tomographic lung cancer screening

The 53.5K-person, low-dose computerized tomographic (LDCT), National Lung Cancer Screening Trial (NLST) achieved a 20% reduction in lung cancer mortality and a 6.7% reduction in all-cause mortality at 6.5-year median follow-up. Failure of European LDCT trials employing null (i.e., unscreened) controls to reproduce this benefit compels caution in adopting a policy of population screening. Additional concerns merit attention: surgical mortality is not trivial; overdiagnosis is substantial; disease-free life expectancy and quality of life are markedly diminished by loss of pulmonary reserve; the combination of overdiagnosis and diminished disease-free life expectancy is pernicious.