Christina Baumann

Screening for Lung Cancer With Low-Dose Computed Tomography: A Systematic Review to Update the U.S. Preventive Services Task Force Recommendation

BACKGROUND Lung cancer is the leading cause of cancer-related death in the United States. Because early-stage lung cancer is associated with lower mortality than late-stage disease, early detection and treatment may be beneficial. PURPOSE To update the 2004 review of screening for lung cancer for the U.S. Preventive Services Task Force, focusing on screening with low-dose computed tomography (LDCT). DATA SOURCES MEDLINE (2000 to 31 May 2013), the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews (through the fourth quarter of 2012), Scopus, and reference lists. STUDY SELECTION English-language randomized, controlled trials or cohort studies that evaluated LDCT screening for lung cancer. DATA EXTRACTION One reviewer extracted study data about participants, design, analysis, follow-up, and results, and a second reviewer checked extractions. Two reviewers rated study quality using established criteria. DATA SYNTHESIS Four trials reported results of LDCT screening among patients with smoking exposure. One large good-quality trial reported that screening was associated with significant reductions in lung cancer (20%) and all-cause (6.7%) mortality. Three small European trials showed no benefit of screening. Harms included radiation exposure, overdiagnosis, and a high rate of false-positive findings that typically were resolved with further imaging. Smoking cessation was not affected. Incidental findings were common. LIMITATIONS Three trials were underpowered and of insufficient duration to evaluate screening effectiveness. Overdiagnosis, an important harm of screening, is of uncertain magnitude. No studies reported results in women or minority populations. CONCLUSION Strong evidence shows that LDCT screening can reduce lung cancer and all-cause mortality. The harms associated with screening must be balanced with the benefits. PRIMARY FUNDING SOURCE Agency for Healthcare Research and Quality.

Smoking Behaviors among Patients Receiving Computed Tomography for Lung Cancer Screening. Systematic Review in Support of the U.S. Preventive Services Task Force

RATIONALE Lung cancer screening using low-dose computed tomography (LDCT) is now widely recommended for adults who are current or former heavy smokers. It is important to evaluate the impact of screening on smoking abstinence rates. OBJECTIVE Among current and former smokers eligible for lung cancer screening, we sought to determine the consequence of screening with LDCT, as well as subsequent results, on smoking cessation and relapse rates. EVIDENCE REVIEW We searched the Cochrane Central Register of Controlled Trials and Cochrane Database of Systematic Reviews (through the fourth quarter, 2012), MEDLINE (2000 to May 31, 2013), reference lists of papers, and Scopus for relevant English-language studies and systematic reviews. To evaluate the effect of LDCT screening on smoking abstinence, we included only randomized controlled trials (RCTs) involving asymptomatic adults. To evaluate the association of particular results and/or recommendations from a screening CT with smoking behaviors, we included results from RCTs as well as cohort studies. MEASUREMENTS AND MAIN RESULTS A total of 8,215 abstracts were reviewed. Three publications from two European RCTs and five publications from three cohort studies conducted in the United States met inclusion criteria. The process of LDCT lung cancer screening did not influence smoking behaviors. LDCT recipients with results concerning for lung cancer had higher abstinence rates than those with scans without such findings. This association may have a dose-response relationship in terms of the number of abnormal CT scans as well as the seriousness of the finding. CONCLUSIONS Limited evidence suggests LDCT lung cancer screening itself does not influence smoking behaviors, but positive results are associated with increased abstinence. As lung cancer screening is implemented in the general population, it is very important to evaluate its association with smoking behaviors to maximize its potential as a teachable moment to encourage long-term abstinence. Clinicians should consider tailoring LDCT result communication to emphasize the importance of smoking abstinence.