Abstract
BACKGROUND: Many results suggested that chemotherapy cannot provide survival benefit for stage II nasopharyngeal carcinoma. It remained unclear whether the efficacy of chemotherapy differed in non-Asian populations. OBJECTIVE: It was designed to analyze the effect of chemotherapy for Asian and non-Asian patients with stage II nasopharyngeal carcinoma. METHOD: Patients were collected using the SEER program. The variables included age, sex, race, marital status, survival time, survival status, TNM stage, radiation and chemotherapy. Utilizing the Rstudio (version: 2024.4.1.748) and R (version: 4.4.1), backward elimination method was employed to screen the variables and multivariate Cox regression analyses was conducted on the screened variables. Kaplan-Meier method was utilized to analyze the survival of sub-stages and different races with T1-2N1M0 stage. The log-rank test was used for statistical analysis. RESULT: 1539 patients were collected. Chemotherapy was statistically significant, with a hazard ratio (HR) of 0.64, P=0.003 in stage II patients. The HR for radiation was 0.33, P<0.001. Chemotherapy didn't improve cancer-specific survival for patients with T2N0M0 stage. Asian and non-Asian races showed no difference in cancer-specific survival in T2N0M0 stage with HR of 1.85, P=0.13. For patients with T1-2N1M0 stage, chemotherapy improved cancer-specific survival with a HR of 0.53, P<0.001. No significant difference was in the Kaplan-Meier analysis between the two sub-stages (P=0.065). In T1-2N1M0 stage, multivariate Cox regression analysis for Asian race indicated that chemotherapy didn't improve cancer-specific survival with a HR of 0.64, P=0.190. For non-Asian race, chemotherapy was found to improve cancer-specific survival, with a HR of 0.51, P<0.001. The Kaplan-Meier analysis of Asian and non-Asian patients with T1-2N1M0 stage exhibited significant differences (P<0.0001). CONCLUSION: Chemotherapy is correlated with the cancer-specific survival in non-Asian patients with T1-2N1M0-stage nasopharyngeal carcinoma, but not in Asian patients at the same stage. For patients with the T2N0M0 stage, chemotherapy is not correlated with the cancer-specific survival rate, regardless of ethnicity.