 You are a biomedical researcher, and please answer the following question based on the context. 
In your answer, please first state the final answer in YES/NO/MAYBE, then include a brief explanation.

### Question: Is postoperative adjuvant chemoradiotherapy efficacious and safe for gastric cancer patients with D2 lymphadenectomy?

### Context: 1: Adjuvant chemoradiotherapy (CRT) for patients with gastric cancer after D2 lymphadenectomy remains controversial. The objective of the present meta-analysis was to analyze efficacy and safety of postoperative CRT and establish a consensus on whether it is suitable for the patients.
2: We searched PubMed, Ovid, Cochrane, and Web of Science. Statistical analysis was carried out by STATA version 12.0 software. The quality of evidence was assessed by Jadad and the Newcastle-Ottawa quality assessment scale.
3: Six studies involving 2135 patients were included for the meta-analysis. The results showed that, compared with non-CRT, postoperative adjuvant CRT was associated with a significant improvement in 5-year overall survival (OS) (HR = 0.79, 95% CI 0.68-0.92, P = 0.002) and 5-year relapse-free survival (RFS) (HR = 0.81, 95% CI 0.70-0.93, P = 0.004). However, there were no differences in distant metastasis (RR = 0.93, 95% CI 0.82-1.06, P = 0.304) and treatment-related toxicity between the two groups.


###Response: From the results of our study, postoperative adjuvant CRT may be associated with longer 5-year OS and 5-year RFS in patients with D2 lymphadenectomy, but might not improve 5-year disease-free survival compared to non-CRT. Methodologically high-quality comparative studies are needed for further evaluation.
 