Extended outcomes of intraperitoneal and systemic chemotherapy for gastric cancer with peritoneal metastases.

Abstract

125 Background: Peritoneal metastasis is common in gastric cancer. It is difficult to treat and carries a grave prognosis. Studies have shown increased drug concentration in the peritoneal cavity when chemotherapy is administered intraperitoneally (IP). We had previously published early results on IP paclitaxel plus XELOX for such patients and now present our longer term data. Methods: Patients with unresectable and/or recurrent gastric adenocarcinoma with peritoneal dissemination and/or positive peritoneal washing cytology, not previously-treated or received prior systemic therapy > 180 days ago and ECOG ≤2 are eligible. Patients were treated with 8 cycles of paclitaxel 40 mg/m2 IP on days 1 and 8, oxaliplatin 100 mg/m2 IV on day 1 and capecitabine 1000 mg/m2 b.i.d. PO for 2 weeks followed by 1 week of rest. The primary endpoint is 1-year overall survival rate and the secondary endpoints are safety, response rate and peritoneal cytological response. Patients who subsequently have no distant metastases, with stable or reduced peritoneal disease and 2 consecutive negative peritoneal cytology would be eligible for conversion gastrectomy. Results: 34 patients have been enrolled and received at least one cycle at the time of reporting. Median no. of cycles is 8 (range: 1–8) and median follow-up is 30.2 months. Median OS is 16.4 months (IQR: 10.1–27.2) and 1-year survival rate is 64.9% (95% CI: 45.5%–78.9%). Of 30 evaluable patients, 1 achieved CR (3.3%), 6 (20.0%) achieved PR, 16 (53.3%) achieved SD and 7 (23.3%) experienced PD. Peritoneal cytology turned negative in 17 of 32 (53.1%) patients. Severe (grade ≥ 3) AE were neutropenia ( N= 7), febrile neutropenia ( N= 3), diarrhoea ( N= 3), hand-foot syndrome ( N= 2), bacterial peritonitis ( N= 2) and hypokalaemia ( N= 4) and tumour perforation ( N= 1). One death occurred due to neutropenic sepsis. 8 patients had conversion gastrectomy with no additional morbidity, with a 1-year survival of 87.5% with a median OS of 18.8 months. Conclusions: XELOX + IP paclitaxel appears to be a well-tolerated and active regimen in gastric cancer with peritoneal metastases, and may offer survival benefits. Finally, conversion gastrectomy may be considered in patients with favourable response. Clinical trial information: NCT01739894.