Efficacy of conversion surgery after neoadjuvant intraperitoneal-systemic chemotherapy in treating peritoneal metastasis of gastric cancer.

PURPOSE: To explore the effectiveness and safety of conversion surgery after neoadjuvant intraperitoneal-systemic chemotherapy (NIPS) in treating gastric cancer patients with peritoneal metastasis.

METHODS

80 patients definitely diagnosed with peritoneal metastasis of gastric cancer treated in our hospital from March 2016 to September 2017 were evaluated. All the patients were randomly assigned into two groups and received oral administration of S-1 + intravenous and intraperitoneal chemotherapy with paclitaxel or oral administration of S-1 + intravenous chemotherapy with oxaliplatin, with 40 patients in each group. Following NIPS conversion therapy, the patients with indications for surgery underwent radical gastrectomy. The short-term efficacy of chemotherapy and incidence of chemotherapy-related adverse reactions were compared between the two groups. The surgical methods, intraoperative conditions (lymph node dissection and surgical margins) and postoperative complications were recorded in the two groups of patients, and the survival in the two groups was recorded via follow-up.

RESULTS

The efficacy was evaluated for all the patients after 4 cycles of treatment. The median cycles of chemotherapy was 6.9 in NIPS group, with a response rate of 85.0% (34/40), while it was 6.4 cycles in control group, with a response rate of 70.0% (28/40). The overall response rate (ORR) after chemotherapy in NIPS group was notably higher than in control group (p=0.041). After chemotherapy, radical gastrectomy was performed in 40 patients with surgical indications, including 22 cases of R0 resection, 10 cases of R1 resection and 8 cases of R2 resection. Some patients developed postoperative complications, including 1 case of incision infection, 3 cases each of ileus and intra-abdominal hemorrhage, 2 cases each of peritonitis and pancreatic fistula, and 4 cases of anastomotic fistula. All the patients were followed up for 2-18 months, and the median follow-up time was 14.1 months in NIPS group and 13.3 months in control group. The median overall survival (mOS) was 13.4 months in NIPS group and 10.8 months in control group.

CONCLUSION

NIPS combined with radical gastrectomy has definite efficacy in treating gastric cancer patients with peritoneal metastasis and cause tolerable adverse reactions, and it can significantly raise the patient survival compared with systemic chemotherapy alone.