Comparison of Survival Benefits of Combined Chemotherapy and Radiotherapy Versus Chemotherapy Alone for Uterine Serous Carcinoma: A Meta-analysis

OBJECTIVE: To date, there is no convincing evidence comparing the impact of combined chemotherapy and radiotherapy with chemotherapy alone in postoperative uterine serous carcinoma (USC), which remains an unclear issue. We conducted a meta-analysis assessing the impact of combined chemotherapy and radiotherapy compared to chemotherapy alone on overall survival in postoperative USC. METHODS: A comprehensive search was performed in the databases of EMBASE, PubMed, Web of Science, and Cochrane Library from inception to March 2016. Studies comparing survival among patients who underwent combined chemotherapy and radiotherapy or chemotherapy alone after surgery for USC were included. Quality assessments were carried out by the Newcastle–Ottawa Scale. Hazard ratio (HR) for overall survival was extracted, and a random-effects model was used for pooled analysis. Publication bias was assessed using both funnel plot and the Egger regression test. Statistical analyses were performed using Stata version 13.0 software. RESULT: Nine retrospective studies with relatively high quality containing 9354 patients were included for the final meta-analysis. The pooled results demonstrated that combined chemotherapy and radiotherapy significantly reduced the risk of death (HR, 0.72; P < 0.0001) compared to chemotherapy alone with a low heterogeneity (I(2) = 21.0%, P = 0.256). Subgroup analyses indicated that calculating HR by unadjusted method may cause the heterogeneity among studies. Exploratory analyses showed that either patients with early stage disease (HR, 0.73; P = 0.011) or advanced stage disease (HR, 0.80; P < 0.0001) have survival benefits from combined chemotherapy and radiotherapy. No significant evidence of publication bias was found. CONCLUSIONS: This is the first meta-analysis examining the role of combined chemotherapy and radiotherapy compared to chemotherapy alone in USC. Our results suggest the potential survival benefits of combined chemotherapy and radiotherapy. Further studies, preferably randomized clinical trials, are needed to confirm our results.