Objective: To investigate and compare the clinicopathological characteristics of gastric stump cancer(GSC) and the recurrent of gastric cancer (RGC) following radical gastrectomy, and to evaluate survival prognosis.
Methods: A retrospective cohort study was performed on clinicopathological and survival data of patients with GSC (n=31) and with RGC (n=105) following radical gastrectomy at the Chinese People's Liberation Army General Hospital between January 1992 and August 2017. GSC was defined as cancer occured in remnant stomach ≥10 years after radical gastrectomy, while RGC was defined as <10 years. Patients of both groups received radical resection or palliative operation with tumor resection and had complete clinicopathological data regarding the first operation and gastric stump operation. T-test was used to compare quantitative data between the two groups, and Pearson χ2 test was used to compare qualitative data between the two groups. Kaplan-Meier method was applied to draw survival curves and log-rank test to assess survival differences.
Results: Of the 136 enrolled patients, 113 were male and 23 were female. In the first operation, compared with RGC group, in GSC group, the Borrmann type and histological differentiation were more better [Borrmann I(: 11/31 (35.5%) vs. 5/105 (4.8%), χ2=23.003, P=0.001; the high differentiation: 15/31 (48.4%) vs. 1/105 (1.0%), χ2=57.137, P=0.001]; the tumor diameter was smaller [<4 cm: 28/31(90.3%) vs. 56/105(53.3%), χ2=14.045, P=0.001]; the pT stage [pT1: 12/31 (38.7%) vs. 3/105 (2.9%), χ2=50.373, P=0.001], pN stage [pN0: 28/31 (90.3%) vs. 19/105 (18.1%), χ2=55.722, P=0.001] and pTNM staging [I(: 26/31 (83.9%) vs. 11/105 (10.5%), χ2=66.688, P=0.001] were earlier. Most of the GSC occurred at non-anastomotic sites, while the recurrence mostly occurred at anastomotic sites [51.6%(16/31) vs. 61.9%(65/105), χ2=7.520, P=0.023]. Compared with RGC group, GSC group had better histological differentiation [high differentiation: 5/31 (16.1%) vs. 2/105(1.9%), χ2=10.029, P=0.007]. There was more histological type change between the first and the second operation in GSC group than that in RGC group[48.4%(15/31) vs. 26.7%(28/105), χ2=5.222, P=0.022]. The overall survival time of GSC group was significantly longer than that of RGC group [mean: (161.0±18.6) months vs. (50.8±27.6) months, respectively, Log-rank: 76.818, P=0.001]. The survival time after the second surgery of GSC group was longer than that of RGC group [mean: (30.7±18.4) months vs. (20.5±15.0) months, P=0.003]. In the subgroup analysis of all the 136 patients according to histological type change between the two surgeries (unchanged 93 patients, changed 43 patients), compared with unchanged group, the overall survival time of changed group was longer [mean: (99.6±56.5) months vs. (72.1±58.1) months, P=0.008].
Conclusions: GSC patients have better histological differentiation and earlier clinical stage of primary gastric cancer, and longer survival time compared with RGC patients. The histological type change between two operations may be used as a new factor to define GSC.