Controversies and challenges in lung cancer screening

Impact of lung cancer screening on stage migration and mortality among the national Veterans Health Administration population with lung cancer

BACKGROUND

Despite randomized trials demonstrating a mortality benefit to low-dose computed tomography screening to detect lung cancer, uptake of lung cancer screening (LCS) has been slow, and the benefits of screening remain unclear in clinical practice.

METHODS

This study aimed to assess the impact of screening among patients in the Veterans Health Administration (VA) health care system diagnosed with lung cancer between 2011 and 2018. Lung cancer stage at diagnosis, lung cancer-specific survival, and overall survival between patients with cancer who did and did not receive screening before diagnosis were evaluated. We used Cox regression modeling and inverse propensity weighting analyses with lead time bias adjustment to correlate LCS exposure with patient outcomes.

RESULTS

Of 57,919 individuals diagnosed with lung cancer in the VA system between 2011 and 2018, 2167 (3.9%) underwent screening before diagnosis. Patients with screening had higher rates of stage I diagnoses (52% vs. 27%; p ≤ .0001) compared to those who had no screening. Screened patients had improved 5-year overall survival rates (50.2% vs. 27.9%) and 5-year lung cancer-specific survival (59.0% vs. 29.7%) compared to unscreened patients. Among screening-eligible patients who underwent National Comprehensive Cancer Network guideline-concordant treatment, screening resulted in substantial reductions in all-cause mortality (adjusted hazard ratio [aHR], 0.79; 95% confidence interval [CI], 0.67-0.92; p = .003) and lung-specific mortality (aHR, 0.61; 95% CI, 0.50-0.74; p < .001).

CONCLUSIONS

While LCS uptake remains limited, screening was associated with earlier stage diagnoses and improved survival. This large national study corroborates the value of LCS in clinical practice; efforts to widely adopt this vital intervention are needed.

Overdiagnosis and overtreatment of ground-glass nodule-like lung cancer

Lung cancer has had one of the highest incidences and mortality in the world over the last few decades, which has aided in the promotion and popularization of screening for lung ground-glass nodules (GGNs). People have great psychological anxiety about GGN because of the chance that it will develop into lung cancer, which makes clinical treatment of GGN a generally excessive phenomenon. Overdiagnosis in screening has recently been mentioned in the literature. An important research emphasis of screening is how to reduce the incidence of overdiagnosis and overtreatment. This paper discusses from different aspects how to characterize the occurrence of overdiagnosis and overtreatment, how to reduce overdiagnosis and overtreatment, and future screening, follow-up, and treatment approaches.