Appraisal of long-time outcomes after curative surgery in elderly patients with gastric cancer: a propensity score matching analysis

BACKGROUND: This study was conducted to assess the long-term outcomes of elderly patients among propensity-score-matched gastric cancer patients after curative gastrectomy and to propose the proper management of elderly gastric cancer patients. METHODS: We enrolled 626 patients with gastric cancer who underwent curative gastrectomy at our institution between January 2004 and December 2015. To minimize selection bias among 2 groups, propensity score matching was performed. RESULTS: Patients were divided into an elderly group over 75 years old (EP group; n = 186) and a non-elderly group (NEP group; n = 440). After propensity score matching, patients were divided into EP group (n = 178) and NEP group (n = 175). Five-year overall survival was significantly lower in the EP group than in the NEP group, consistent with a subgroup analysis of each stage. However, the 5-year disease-specific survival among all enrolled patients and those with stage I and II disease did not differ significantly. Moreover, in the subgroup of stage III patients, 5 year disease-specific survival was significantly lower in the EP group (23.0%) than in the NEP group (59.4%; P = 0.004). Because elderly patients with stage III disease had an extremely poor prognosis, we decided to compare the two groups with stage III. The EP group contained significantly fewer patients with D2 lymphadectomy (P = 0.002) and adjuvant chemotherapy (P < 0.001) than the NEP group. C-reactive protein to albumin ratio was significantly higher in patients in the EP group than in the NEP group (P = 0.046), and the prognostic nutritional index was significantly lower in patients in the EP group than in the NEP group (P = 0.045). Multivariate analysis revealed that the prognostic nutritional index and lymphatic invasion were independent prognostic factors. CONCLUSIONS: Elderly gastric cancer patients with stage III disease showed poorer disease-specific survival compared with non-elderly patients, which may be due to a poorer nutritional and inflammatory background, fewer D2 lymphadenectomies, and a lack of adjuvant chemotherapy. The safe induction of standard lymphadenectomy and adjuvant chemotherapy with perioperative aggressive nutritional support may improve the prognosis of elderly gastric cancer patients with stage III disease.