Strategy to reduce peritoneal metastases in gastric cancer

The study covered in this summary was published on researchsquare.com as a preprint and has not yet been peer reviewed.

Key takeaway

• Adding hyperthermic intraperitoneal chemotherapy to systemic chemotherapy after radical gastrectomy reduces the occurrence of peritoneal metastases and improves disease-free survival (DFS) for patients with locally advanced gastric cancer.

Why this matters

• Surgery and postoperative chemotherapy are standard of care for advanced gastric cancer, but up to half of patients develop peritoneal metastases with poor prognosis.
• There is no consensus on how to prevent peritoneal metastases.
• With hyperthermic intraperitoneal chemotherapy, the abdominal cavity is bathed in chemotherapy that has been heated, directly killing free cancer cells and micrometastases.
• The findings suggest that adding hyperthermic intraperitoneal chemotherapy to standard treatment greatly reduces the risk of peritoneal metastases.

Study design

• The investigators randomly assigned 134 patients with advanced gastric cancer evenly to receive either systemic chemotherapy alone or systemic chemotherapy plus hyperthermic intraperitoneal chemotherapy after radical gastrectomy.
• The hyperthermic intraperitoneal chemotherapy group had 3 L of heated saline containing 40 mg/m² of cisplatin circulated in their peritoneal cavities for an hour. The procedure was performed twice within 72 hours of surgery.
• Systemic chemotherapy consisted of six to eight cycles of S-1 combined with oxaliplatin (SOX regimen) starting 4-6 weeks after surgery.
• Most patients (90%) had stage III disease, and the rest stage II.
• Median follow-up was 44 months.

Key results

• Overall, the 3-year DFS rate was 73.8% with hyperthermic intraperitoneal chemotherapy versus 61.2% without it (P = .031).
• In addition, 21% of patients in the hyperthermic intraperitoneal chemotherapy group developed peritoneal metastases versus 40.3% with standard care (P = .015)
• The 3-year overall survival was 73.9% in the hyperthermic intraperitoneal chemotherapy group versus 77.6% in the standard care arm, but the difference was not significant (P = .737).
• There were no serious adverse events related to hyperthermic intraperitoneal chemotherapy, and postoperative complications were similar between the groups.
• Grade 3 or 4 adverse events occurred in 14.2% of patients; there were no statistically significant between-group differences.
• Metastases to other sites, such as the liver and distant lymph nodes, were also similar between the two arms.

Limitations

• Follow-up might have been too short to detect a difference in overall survival.
• The trial was conducted at a single-center and was relatively small.

Disclosures

• The study received no external funding, and the investigators did not report any financial relationships.

This is a summary of a preprint research study, “Hyperthermic Intraperitoneal Chemotherapy (HIPEC) Plus Systemic Chemotherapy Versus Systemic Chemotherapy Alone in Locally Advanced Gastric Cancer After D2 Radical Resection: A Randomized Controlled Study,” led by Pengfei Yu of the Zhejiang Cancer Hospital, Hangzhou, China. The study has not been peer reviewed. The full text can be found at researchsquare.com.

A version of this article first appeared on Medscape.com.