Impact of perioperative treatment on survival of resectable gastric cancer patients after D2 lymphadenectomy: a single European centre propensity score matching analysis.

Background To determine the effects of perioperative treatment of gastric cancer patients, we conducted an analysis with propensity score matched patient groups to determine the role of perioperative chemotherapy in patients after D2 lymphadenectomy. Patients and methods From our database of 1563 patients, 482 patients were selected with propensity score matching and divided into two balanced groups: 241 patients in the surgery only group and 241 patients in the perioperative group. The long-term results of treatment were compared between the two groups. Results Most of the included patients received radio-chemotherapy with capecitabine (n = 111; 46%) and perioperative chemotherapy with epirubicin, oxalliplatin and capecitabine (n = 91; 37.7%). 92.9% of the patients received a D2 lymph node dissection. Perioperative morbidity was similar between surgery only (18.3%) and perioperative treatment groups (20.7%) (p = 0.537). The perioperative mortality was not influenced by perioperative treatment. A pathological response was observed in 12.5% of patients. The overall 5-year and median survivals were significantly higher in the perioperative treatment group (50.5%; 51.7 moths) compared to surgery only group (41.8%; 34.9 months; p = 0.038). The subgroup analysis revealed that only patients with the TNM stages T3 (p = 0.028), N2 (p = 0.009), N3b (p = 0.043), and UICC stages IIIb (p = 0.003) and IIIc (p = 0.03) significantly benefit from perioperative treatment. Conclusions Perioperative treatment in radically resected gastric cancer patients after D2 lymphadenectomy was beneficial in stages IIIb and IIIc. The effects of perioperative treatment in lower stages could be negated by the effects of the radical surgery in lower stages and in higher stages by the biology of the disease.