The impact of Adult Comorbidity Evaluation-27 on the clinical outcome of elderly nasopharyngeal carcinoma patients treated with chemoradiotherapy or radiotherapy: a matched cohort analysis

Objectives: To evaluate the prognostic significance of Adult Comorbidity Evaluation-27 (ACE-27) for elderly patients (age ≥70 years) with locoregionally advanced nasopharyngeal carcinoma (NPC) treated with Intensity-Modulated Radiotherapy (IMRT), with or without chemotherapy. Methods: 206 elderly patients with locoregionally advanced NPC treated from December 2006 to December 2016 were involved into analysis as the training cohort. Besides, a separate cohort of 72 patients from the same cancer center collected between January 2003 and October 2006 served as the validation cohort. By using propensity score matching (PSM), we created a balanced cohort by matching patients who received chemoradiotherapy with patients who received IMRT alone. Treatment toxicities were calculated between CRT and RT groups using the χ(2) test. The primary endpoint was cancer-specific survival (CSS). Multivariate analysis was performed to assess the relative risk for each factor by using a Cox's proportional hazards regression model. Results: The median follow-up was 39.0 months (range = 3-137 months). In the PSM cohort, patients in the CRT group achieved comparable survival compared with patients in the RT group. The 3-year CSS rate was 64.3% and 65.2%, respectively (P =0.764). In multivariate analysis, the addition of chemotherapy to IMRT was not an independent prognostic factor for CSS, whereas a high ACE-27 score was an independent risk factor. In subgroup analysis with ACE-27 score ≥ 2, the 3-year CSS rate was worse in patients from the CRT group (63.5% vs. 46.3%, P = 0.041). Conclusions: CRT is comparable to IMRT alone for elderly patients with locoregionally advanced NPC. The ACE-27 tool may help to identify high-risk subgroup for poor disease outcome and tailor individualized treatment.