# Current Challenges and Future Directions in the Multimodal Management of Gastric Cancer with Peritoneal Metastases

## TL;DR

Gastric cancer with peritoneal metastases is hard to treat, and better staging and personalized therapies are needed to improve outcomes.

## Contribution

The paper highlights the need for validated biomarkers and personalized multimodal strategies in managing gastric cancer with peritoneal metastases.

## Key findings

- Laparoscopy is essential for accurate staging and avoiding unnecessary surgery.
- Locoregional therapies like CRS–HIPEC and PIPAC show promise but require further validation.
- Current systemic therapies have limited effectiveness in the peritoneal compartment.

## Abstract

Peritoneal metastases from gastric cancer represent one of the most challenging disease presentations, often leading to limited survival and a rapid decline in quality of life. Although modern treatments such as chemotherapy, immunotherapy and targeted therapies have improved outcomes in metastatic gastric cancer overall, they are far less effective when the disease involves the peritoneal cavity. Correct treatment planning must therefore begin with accurate disease assessment, including staging laparoscopy, which can detect hidden peritoneal spread and help avoid unnecessary major surgery. Several innovative locoregional approaches have shown encouraging results in selected patients, but they are not yet fully validated for widespread adoption. Most importantly, we still lack reliable biological indicators to guide treatment selection and match the right approach to the right patient. Continued research is crucial to develop more personalized strategies and improve care for individuals with gastric cancer complicated by peritoneal metastases.

Peritoneal metastases represent one of the most dreadful manifestations of gastric cancer and continue to drive poor outcomes despite significant advances in systemic therapy. Accurate staging—beginning with laparoscopy—remains essential for avoiding non-beneficial surgery and ensuring appropriate allocation to systemic or locoregional treatment pathways. Although modern systemic agents, including immunotherapy and targeted therapies, have transformed the broader management of metastatic disease, their impact in the peritoneal compartment remains limited, reflecting its unique biological and pharmacokinetic constraints. Locoregional approaches such as CRS–HIPEC, PIPAC, and NIPS have expanded the therapeutic armamentarium and have shown encouraging signals in selected populations. Recent randomized studies, including ESTOK01 and PERISCOPE II, emphasize the importance of careful patient selection, technical standardization, and optimal sequencing, while ongoing trials—such as PREVENT, GASTRICHIP, and CONVERGENCE—seek to refine the integration of systemic and intraperitoneal strategies. Yet the field continues to advance without the benefit of validated predictive biomarkers capable of guiding therapeutic decisions. This limitation constrains clinical progress and underscores the need for a stronger translational framework. Future improvement in the management of gastric cancer with peritoneal metastases will depend on the identification of robust biological predictors of response, enabling more rational patient selection and the development of truly personalized multimodal approaches.