Gender-Specific Survival of Nasopharyngeal Carcinoma in Endemic and Non-Endemic Areas Based on the US SEER Database and a Chinese Single-Institutional Registry.

Purpose: To investigate the prognostic implications of gender in nasopharyngeal carcinoma (NPC) utilizing data from two independent cohorts: the Xiamen (XM)-NPC cohort (an endemic area in China) and the United States Surveillance, Epidemiology, and End Results (SEER)-NPC cohort (a non-endemic area).

Methods: We included patients diagnosed with NPC from both the XM-NPC and SEER-NPC cohorts. Statistical analysis involved the chi-square test, Kaplan-Meier method, and multivariate Cox regression analyses.

Results: The study identified 728 patients in the XM-NPC cohort and 2237 in the SEER cohort. In the XM-NPC cohort, 515 (70.7%) were male and 213 (29.3%) were female. In the SEER-NPC cohort, 1597 (71.4%) were male and 640 (28.6%) were female. The male-to-female ratio peaked at ≤25 years (2.33) and 46-55 years (2.79) in the XM-NPC cohort, and at ≤25 years (2.07) and 56-65 years (3.24) in the SEER-NPC cohort. The lowest ratios were observed among patients aged 26-35 years in both cohorts (XM-NPC: 1.64; SEER-NPC:1.38). In the XM-NPC cohort, females had significantly better overall survival (P=0.022) and distant metastasis-free survival (P=0.038) compared to males. Similarly, in the SEER-NPC cohort, gender was found to be an independent prognostic factor for overall survival, with females showing better outcomes (P=0.038). Consistent trends were observed in patients aged >45 years in both cohorts, while survival outcomes were comparable between genders in patients aged ≤45 years.

Conclusion: Gender independently influences survival outcomes of NPC in both endemic and non-endemic areas.