Lung Cancer Screening
Li Liu, MD
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: November 1, 2001
I have learned from you site and others that lung cancer is the leading cause of cancer deaths. Does it make sense to screen general population with chest x-ray or CT scan so that patients can be detected earlier and hopefully cured?
Li Liu, MD, Editorial Assistant for OncoLink, responds:
This is an excellent question.
Despite research efforts to improve diagnostic and therapeutic effectiveness, there has been little success in enhancing lung cancer prognosis. The survival rate for lung cancer has shown little change during the past several decades. Unfortunately, most patients present with advanced disease, at which point therapeutic options are less than optimal. Screening for early detection of many diseases is becoming more prevalent as new and more effective techniques become available. Some early lung cancer screening trials using chest x-ray and sputum cytology have demonstrated that lung cancers identified by screening methods were more frequently early-stage tumors. However, there was no impact in overall survival when all deaths were considered (Am Rev Respir Dis 1984 Oct; 130(4): 545-9; Int J Cancer 1984 Jul 15; 34(1): 1-4). The National Cancer Institute (NCI) concluded that screening with chest X-ray had no effect on lung cancer mortality.
Serious methodological issues have risen in regards to those old studies. Concerns about study design, statistical analysis, contamination, inherent biases, and older forms of technology have prompted new early-detection trials using improved diagnostic-imaging techniques. Several new screening studies using computed tomography (CT) have yielded preliminary findings with encouraging results, creating a growing enthusiasm for screening with low-dose CT-a more sensitive technique than chest X-ray (Radiology 1996 Dec; 201(3): 798-802; Lancet 1998 Apr 25;351(9111):1242-5; Lancet 1999 Jul 10;354(9173):99-105). However, many physicians have expressed concern that routine use of early-detection methods is premature and have recommended waiting to implement widespread and expensive screening programs until legitimate health outcome benefits and cost-effectiveness can be confirmed by further studies.