The influence of adjuvant therapy on survival in patients with indeterminate margins following surgery for non-small cell lung cancer

Background: The significance of indeterminate margins following surgery for non-small cell lung cancer (NSCLC) is unknown. We evaluated the influence of adjuvant therapy on survival in patients whose cancer showed indeterminate margins. Methods: Patients whose cancer showed indeterminate margins following surgery for NSCLC were identified in the National Cancer Database between 2004 and 2015, and stratified by receipt of adjuvant treatment. The primary outcome was overall survival, which was evaluated with multivariable Cox proportional hazards. Results: Indeterminate margins occurred in 0.31% of 232,986 patients undergoing surgery for NSCLC and was associated with worse survival compared with margin negative resection (adjusted hazard ratio, 1.53; 95% confidence interval, 1.40-1.67). Anatomic resection was protective against the finding of indeterminate margins in logistic regression. Amongst 553 patients with indeterminate margins, 343 (62%) received no adjuvant therapy, 96 (17%) received adjuvant chemotherapy, 33 (6%) received adjuvant radiation, and 81 (15%) received adjuvant chemoradiation. Any mode of adjuvant therapy was not associated with improved survival compared with no further treatment. Conclusions: The finding of indeterminate margins is reported in 0.31% of patients undergoing curative-intent surgery for NSCLC. This was associated with worse overall survival compared with complete resection and not mitigated by adjuvant therapy. The risks and benefits of adjuvant therapy should be carefully considered for patients with indeterminate margins after surgery for NSCLC.