Results PERISCOPE II study published

In this European multicenter randomized controlled trial, 102 patients with resectable gastric adenocarcinoma, limited peritoneal metastases (PCI<7) and/or tumor-positive peritoneal cytology were randomized. In absence of disease progression after at least 3 cycles of systemic therapy, patients were randomized to either continuation of systemic therapy (standard arm) or gastrectomy, cytoreductive surgery (CRS) and HIPEC (experimental arm).

No survival benefit for the experimental approach

The study showed no overall survival benefit for the experimental approach. Median overall survival was 16.6 months in the standard arm and 15.7 months in the experimental arm. Progression-free survival also did not significantly differ between the two groups. Treatment-related toxicity, however, was substantially higher in the experimental arm. Serious adverse events occurred more often in patients assigned to surgery plus CRS/HIPEC, and three treatment-related deaths were reported within 100 days after randomization, all in the experimental arm.

Surgical oncologist Johanna van Sandick: “The PERISCOPE II study addressed an important clinical question in a setting where high-level comparative evidence has been lacking. Our findings show that adding gastrectomy, cytoreductive surgery, and HIPEC to systemic therapy did not lead to a survival benefit as compared with systemic therapy alone in this patient group, while it did increase treatment-related morbidity. This so-called ‘negative’ trial is an important contribution to patient care. It helps prevent future patients from undergoing intensive treatment without clear benefit, while refining the questions that deserve further investigation.”

Implications for patient care

The PERISCOPE II study is the first European prospective multicenter randomized controlled trial to directly compare CRS/HIPEC with systemic therapy alone in patients with gastric cancer and limited peritoneal metastases. Its findings help clarify that systemic therapy remains the standard of care in this patient group. As an investigator-initiated study, the PERISCOPE II study also shows why sustained funding for academically led clinical trials is essential: these studies generate the evidence needed to enrich clinical practice guidelines and to determine what should not enter routine patient care because it does not provide clear benefit. Future progress in this field will likely depend on better understanding tumor biology, improved staging, and more precise patient selection.

This project is financially supported by KWF Dutch Cancer Society, the Netherlands Organization for Health Research and Development (ZonMW), the Dutch Ministry of Health (VWS), the family of Henk Boot, the Bengt Ihre Research Foundation, and the Swedish Cancer Society.