Abstract
BACKGROUND: Current data suggest better survival in various cancer types but increased treatment toxicity in female compared with male patients. In this article, we report a pooled analysis of sex-related differences in survival outcomes and safety in patients with resectable stage III non-small-cell lung cancer (NSCLC) treated in five prospective clinical trials. PATIENTS AND METHODS: Data from 499 patients included in five Swiss Group for Clinical Cancer Research (SAKK) trials for resectable stage III NSCLC were pooled. All patients were treated with three cycles of chemotherapy (cisplatin/docetaxel), either alone (n = 207, 41%), with sequential radiotherapy (n = 229, 46%) or with sequential perioperative programmed death-ligand 1 blockade (n = 62, 12%). RESULTS: Of 499 patients included, 341 (68.3%) were male. Median event-free survival (EFS) [24.4 versus 11.8 months, hazard ratio (HR) 1.32, 95% confidence interval (CI) 1.06-1.64, P = 0.014] and median overall survival (OS) (59.3 versus 26.1 months, HR 1.45, 95% CI 1.15-1.83, P = 0.0018) were significantly longer in female patients compared with male patients. OS/EFS remained significant in a multivariable Cox regression model. While the cause-specific hazard of non-cancer-related death was increased in males (HR 2.14, 95% CI 1.32-3.46, P = 0.0019), the risk of tumor-related death was not significantly different between sexes (HR 1.26, 95% CI 0.96-1.65, P = 0.09). No significant differences in treatment-related grade ≥3 adverse events (62.5% versus 69.7%) or treatment discontinuation (3.2% versus 3.2%) were observed. CONCLUSION: In this pooled analysis, female patients with resectable stage III NSCLC had longer EFS and OS than males, mainly due to lower non-cancer-related mortality. Given the retrospective design and limited sample size, these results should be interpreted with caution. Prospective studies are needed to confirm these findings and explore underlying causes of sex-based differences.