G08 - Concurrent chemoradiotherapy plus adjuvant chemotherapy versus chemoradiotherapy alone or radiotherapy alone in locoregionally advanced nasopharyngeal carcinoma: a meta-analysis

Abstract

Background: Treatment of locally advanced (stages III-IV) Nasopharyngeal Carcinoma (NPC) has still some controversies. Historically, radiotherapy (RT) was considered the treatment of choice for this inoperable tumors at advanced stages but several studies showed that concurrent chemoradiotherapy (CCRT) led to an improvement in overall survival rates. Anyway, radiotherapy can be considered a valid treatment option avoiding the toxicities of the combined therapy. The benefits of combining CCRT with adjuvant chemotherapy (AC) for treatment of locally advanced NPC have not been established. Aim of this study was to analyze the studies evaluating the different treatment strategies in order to determine the efficacy of CCRT + AC compared to CCRT or RT alone. Methods: We performed a meta-analysis comparing CCRT + AC vs CCRT alone (group 1) and CCRT + AC vs RT alone (group 2). In group 1 two studies were included, in group 2 four studies were included. The analysis was based on both randomized clinical trials (RCT) and retrospective studies. The main end-point was Overall Survival (OS). Locoregional (LRF) and distant (DF) failures were also analyzed. Hazard Ratios were used for effect size comparison. Results: When overall survival was analyzed, CCRT + AC showed better outcomes compared with RT alone (HR: 0.70, 95% CI 0.57-0.87 p-value <0.005). On the other hand, no statistical significant difference was found regarding the local and distant recurrence of disease (LRF HR: 0.57, 95% CI 0.39-0.85 p-value >0.005, DF HR: 0.76, 95% CI 0.56-1.01 p-value >0.005).When comparing CCRT + AC vs. CCRT alone no significant improvement was found for any of the end-points analyzed (OS HR = 0.77, 95% CI 0.51-1.18 p-value 0.222; LRF HR: 0.67, 95% CI 0.35-1.28 p-value 0.228; DF HR: 0.81, 95% CI 0.57-1.18 p-value 0.262). Conclusions: CCRT + AC showed better outcomes when compared with RT alone. No difference has been shown when CCRT + AC vs CCRT alone were analyzed. For these reasons, the omission of AC to reduce toxicity can be taken into consideration. On the other hand, it must be pointed out that more studies, in particular well designed RCT, are needed in order to strengthen the results of this meta-analysis. Also, it should be noted that the majority of the studies regarding NPC are conducted on areas in which this cancer is endemic. It can be speculated that some differences in treatment response exist between different populations, so it is auspicable that studies on more heterogeneous populations will be conducted.