Prognostic factors of laparoscopic radical total gastrectomy for elderly patients with primary gastric cancer using propensity score matching analysis

Abstract

Objective To investigate the prognostic factors of laparoscopic radical total gastrectomy for elderly patients with primary gastric cancer. Methods The retrospective case-control study was adopted by using propensity score matching analysis. The clinicopathological data of 338 elderly patients with primary gastric cancer who were admitted to the Union Hospital of Fujian Medical University between January 2010 and December 2012 were collected, including 246 receiving laparoscopic radical total gastrectomy (LTG) and 92 receiving open radical total gastrectomy (OTG). The follow-up was performed to detect postoperative survival of patients by outpatient examination, home visit, correspondence and telephone interview till December 2015. Observation indicators included: (1) the clinicopathological data: gender, age, body mass index (BMI), Charlson scores of preoperative concomitant diseases, American Society of Anesthesiologists (ASA) grading, tumor location and diameter, number of lymph node dissected, pathologic classification of tumors and pathologic TNM (pTNM) stage. (2) All the patients were allocated into the LTG group and OTG group after a propensity score matching analysis. (3) Prognostic indicator included 3-year cumulative survival rate. (4) Prognostic analysis indicators included gender, tumors location and diameter, surgical procedures, pathological classification and tumor clinical staging. (5) Independent prognostic factors were done by the stratification analysis. Measurement data with normal distribution were presented as ±s and comparison between groups was analyzed by LSD-t test and matching t test. Count data were analyzed using the chi-square test. The propensity score matching analysis was done using Logistic regression model. The survival curve was drawn by Kaplan-Meier method and survival rate was calculated using the Log-rank test. The univariate analysis and multivariate analysis were done using the COX proportional risk model. Results Of 338 patients, there were 87 matched pairs (87 patients in each group). There were significant differences in the age and pTNM stage before propensity score matching between the 2 groups (t=-1.692, χ2=8.437, P 0.05). Among 338 patients before propensity score matching, 306 patients were followed up for a median time of 32 months (range, 2-67 months). The 3-year cumulative survival rate was 58.2% and 45.3% in the LTG and OTG groups, respectively, showing a significant difference between the 2 groups (χ2=4.989, P 0.05). The results of univariate analysis in the 174 matched patients showed that tumor diameter and clinical staging were related factors affecting the prognosis of elderly patients undergoing radical total gastrectomy of primary gastric cancer [OR=2.697, 4.493, 95% confidence interval (CI): 1.695-4.289, 2.466-8.186, P 0.05). Conclusions LTG for elderly patients with primary gastric cancer is equivalent to OTG in the prognosis, and the age is not an absolute contraindication. The stage Ⅲ of tumor is an independent risk factor affecting the poor prognosis of elderly patients undergoing radical total gastrectomy of primary gastric cancer. Key words: Gastric neoplasms; Elderly; Gastrectomy; Laparoscopy; Prognosis; Propensity score matching