Propensity score matching analysis of the survival outcome and toxicity of different treatment modalities for the elderly nasopharyngeal carcinoma patients.

Abstract

e23029 Background: With the aging society was coming, more elderly nasopharyngeal carcinoma NPC patients should be pay attention. However, no guideline is proposed for them due to lack of prospective clinical trials. We aimed to use propensity score matching method to evaluate the survival outcome and toxicity of the different treatment modalities for them. Methods: II-IV(UICC 8th) elderly NPC patients (≥65 years) were retrospectively enrolled between 2004 to 2016 in our center. All the patients received definitive IMRT, and were allocated into radiotherapy only (RT), concurrent chemoradiotherapy (CCRT) and neoadjuvant chemotherapy followed with CCRT (NACT). Cisplatin-based chemotherapy was used. Survival outcomes and toxicity were analyzed using propensity score-matching method. Results: There were 142 patients included, and the median age was 68 years. The median follow-up time was 47 months. 23 patients received RT only, 61 patients received CCRT and 58 patients received NACT. After matching for gender, age, T and N stage, chemotherapy and non-chemotherapy patients (22 pairs) were analyzed and shown the chemotherapy group had a better OS (86% vs 68%, p= 0.031). The 3-years LRFS, DMFS and DFS of chemotherapy and non-chemotherapy was 95% and 85% ( p= 0.251), 95% and 86% ( p= 0.307), 86% and 73% ( p= 0.309). Furthermore, 41 pairs who underwent chemotherapy were sub-analyzed according to different modalities. CCRT group showed a comparable 3-years LRFS (100% vs 94%, p= 0.143), DMFS (87% vs 89%, p= 0.608), DFS (81% vs 84%, p= 0.892) and OS (79% vs 66%, p= 0.080) with NACT. For acute toxicity, the incidence of G3-5 bone marrow suppression in non-chemotherapy was significantly lower than chemotherapy group (8.7% vs 36.4%, p= 0.31), and the incidence of G3-5 mucositis was similar ( p= 0.517). Besides that, there was no significant difference in the incidence of G3-5 bone marrow suppression and mucositis between CCRT and NACT group ( p= 0.824, p= 0.618). Conclusions: Chemoradiotherapy could improve the survival rate of the elderly NPC patients compared with radiotherapy only. The acute toxicity of CCRT and NACT was similar and acceptable. CCRT was still the standard treatment modality for them. As for the elderly NPC patients who are in good performance status and comorbidity conditions, NACT might be also worthy of recommendation.