Adjuvant chemotherapy for elderly patients with stage I non-small-cell lung cancer ≥4 cm in size: An SEER-Medicare analysis

Background: The role of adjuvant chemotherapy for non-small-cell lung cancer (NSCLC) stage I patients with tumors size ≥4 cm is not well established in the elderly. Patients and methods: We identified 3289 patients with stage I NSCLC (T2N0M0 and tumor size ≥4 cm) who underwent lobectomy from the Surveillance, Epidemiology and End Results (SEER)-Medicare linked database diagnosed from 1992 to 2009. Overall survival and rates of serious adverse events (defined as those requiring admission to hospital) were compared between patients treated with resection alone, platinum-based adjuvant chemotherapy, or postoperative radiation (PORT) with or without adjuvant chemotherapy. Propensity scores for receiving each treatment were calculated and survival analyses were conducted using inverse probability weights based on the propensity score. Results: Overall, 84% patients were treated with resection alone, 9% received platinum-based adjuvant chemotherapy, and 7% underwent PORT with or without adjuvant chemotherapy. Adjusted analysis showed that adjuvant chemotherapy [hazard ratio (HR), 0.82; 95% confidence interval (CI) 0.68-0.98] was associated with improved survival compared with resection alone. Conversely, the use of PORT with or without adjuvant chemotherapy (HR 1.91; 95% CI 1.64-2.23) was associated with worse outcomes. Patients receiving adjuvant chemotherapy had more serious adverse events compared with those treated with resection alone, with neutropenia (odds ratio, 21.2; 95% CI 5.8-76.6) being most significant. No significant difference was observed in rates of fever, cytopenias, nausea, and renal dysfunction. Conclusions: Platinum-based adjuvant chemotherapy is associated with reduced mortality and increased serious adverse events in elderly patients with stage I NSCLC and tumor size ≥4 cm.