Significance of chemotherapy for older patients with nasopharyngeal carcinoma in the intensity-modulated radiotherapy era: A propensity score matching analysis.

INTRODUCTION: This study aimed to evaluate the survival and prognosis of older patients with nasopharyngeal carcinoma (NPC) who received intensity-modulated radiotherapy (IMRT) alone versus IMRT plus chemotherapy using propensity score matching (PSM). MATERIALS AND METHODS: We enrolled 841 older patients with NPC aged 60 years and above without metastasis receiving IMRT alone or chemoradiotherapy from 2012 to 2019. The comorbidity was assessed by adult comorbidity evaluation (ACE-27). PSM (1:3 ratio) was conducted between the two treatment groups based on four clinical factors including age, T-stage, N-stage, and ACE-27. Differences in overall survival (OS) and cancer-specific survival (CSS) were analyzed by the Kaplan-Meier method and Cox proportional hazard model. RESULTS: A total of 841 patients with NPC were included in the study, there were 94 patients in the IMRT alone group and 747 patients in the chemoradiotherapy (CRT) group. After a 1:3 ratio PSM, 89 patients underwent IMRT alone and 223 patients underwent CRT. The baseline analysis showed an insignificant difference after PSM (P > 0.05). In multivariate analysis, we found that ACE-27 (≥2) was associated with worse five-year OS and CSS (HR = 1.994, 95%CI: 1.276-3.116, P = 0.002; HR = 1.849, 95%CI: 1164-2.935, P = 0.009, respectively). Chemotherapy was an independent prognosticator of better five-year OS and CSS (HR = 0.333, 95%CI: 0.213-0.552, P < 0.001; HR = 0.327, 95%CI: 0.204-0.524, P < 0.001, respectively). In terms of subgroup analysis, chemotherapy was a statistically beneficial predictor for stage III-IV patients (P < 0.05), but no significant difference in stage II patients (P > 0.05). About the adverse events, the incidence of hepatotoxicity (P = 0.002), neutropenia (P < 0.001), anemia (P < 0.001), and thrombocytopenia (P < 0.001) were significantly higher in the CRT group. DISCUSSION: Combined modality therapy was associated with improved five-year OS and CSS in older adults with stage III-IV NPC, but was not associated with improved survival over IMRT alone in patients with stage II disease. Risk factors including T3-4 disease, positive lymph nodes, ACE-27 score ≥ 2, and IMRT alone were were associated with worse OS and CSS. There was a significantly higher incidence of hepatotoxicity and blood toxicity in the CRT group.