Outcomes of resected lung cancer diagnosed through screening and incidental pulmonary nodule programs in a Mississippi Delta cohort.

Introduction Early lung cancer detection programs improve surgical resection rates and survival, but may skew towards more indolent cancers. Methods Hypothesizing that differences in stage-stratified survival indicate differences in biologic aggressiveness and possible length-time and over-diagnosis bias, we assessed a cohort undergoing curative-intent resection, categorized by diagnostic pathways: screening, incidental pulmonary nodule program, and non-program-based. Survival was analyzed using Kaplan-Meier plots, log-rank tests, and Cox regression, comparing aggregate and stage-stratified survival across cohorts with Tukey’s method for multiple testing. Results Of 1588 patients, 111 (7%), 357 (22.5%), and 1120 (70.5%) were diagnosed through screening, pulmonary nodule and non-program-based pathways; 0% v 9% v 6% were >80 years old (p=0.0048); 17%, 23% and 24% had a Charlson Co-morbidity Score ≥2 (p=0.0143); 7%, 6% and 9% had lepidic adenocarcinoma; 26%, 31% and 34% had poorly or undifferentiated tumors (p=0.1544); 93%, 87% and 77% had clinical stage I (p<.0001).Aggregate 5-year survival was 87%, 72%, and 65% (p=0.0009), including 95%, 74%, and 74% for pathologic stage I. Adjusted pairwise comparisons showed similar survival between screening and nodule program cohorts (p=0.9905). However, differences were significant between screening and non-program-based cohorts (p=0.0007, adjusted hazard ratio (aHR) 0.33 [95% CI: 0.18–0.6]) and nodule versus non-program cohorts (aHR 0.78 [95% CI: 0.61–0.99]). Stage I comparisons yielded p=0.2256, 0.1131, and 0.911. In respective pathways, 0%, 2%, and 2% of stage I patients >80 years had a Charlson score ≥2 (p=0.3849). Conclusions Neither length-time, nor over-diagnosis bias was evident in NSCLC diagnosed through screening or incidental pulmonary nodule programs.