BMI-adjusted prognosis of signet ring cell carcinoma in patients undergoing radical gastrectomy for gastric adenocarcinoma

BackgroundCompared with other histologic types, signet ring cell gastric carcinoma (SRC) has unique oncological characteristics, and its implication on the prognosis of gastric cancer patients remains unclear. The purpose of this study was to evaluate the prognostic impact of body mass index (BMI) on SRC patients.MethodsA retrospective analysis was performed using the clinical records of 3342 patients with SRC or tubular adenocarcinoma who underwent radical gastrectomy between 2000 and 2014. Patients were divided into three groups according to histologic subtype: SRC, well-to-moderately differentiated adenocarcinoma (WMD), and poorly differentiated adenocarcinoma (PD). We compared the survival of SRC patients with that of tubular adenocarcinoma patients according to BMI.ResultsThe 5-year survival of SRC was significantly worse than that of WMD (P < 0.001) but superior to that of PD (P < 0.001). BMI-stratified analysis showed that in the high-BMI group, the prognosis of SRC was similar to that of WMD (P > 0.05) and better than that of PD (P < 0.001). In normal-BMI patients, SRC had a worse prognosis than WMD (P < 0.001) but a more favorable prognosis than PD (P < 0.001). SRC among low-BMI patients displayed much poorer survival than did both WMD (P < 0.001) and PD (P = 0.005). Multivariate analysis indicated that the risk of death was the lowest in SRC patients with a high BMI and highest for SRC patients with a low BMI (low-BMI hazard ratio: SRC 1 vs. WMD 0.51 and PD 0.53).ConclusionSRC has worse prognostic impact as BMI decreases. BMI leads to differing prognosis of SRC compared with tubular adenocarcinoma.