# Staging Laparoscopy in High-Risk Gastric Cancer: A Decade of Real-World Evidence and Therapeutic Impact from a Tertiary Referral Center

## TL;DR

Staging laparoscopy improves accuracy in diagnosing advanced gastric cancer and helps tailor treatment plans.

## Contribution

Demonstrates that staging laparoscopy detects hidden peritoneal disease in high-risk gastric cancer patients, altering treatment decisions.

## Key findings

- Staging laparoscopy identified peritoneal involvement in 23% of high-risk gastric cancer patients.
- Treatment plans were modified in all cases based on laparoscopy findings.
- Procedure was safe with no complications and enabled personalized therapy choices.

## Abstract

Gastric cancer is often diagnosed in advanced stages, and standard imaging frequently fails to reveal subtle peritoneal spread that can radically change prognosis and treatment goals. Staging laparoscopy enables the direct visualization of the abdominal cavity and cytological assessment of peritoneal fluid, offering diagnostic accuracy beyond noninvasive methods. In this study, we reviewed a decade of experience in patients with clinical features indicating high risk for occult peritoneal disease. Nearly one quarter had previously undetected peritoneal involvement, and these findings modified the therapeutic plan in all cases, guiding the selection of systemic therapy, cytoreductive approaches, or intraperitoneal treatments. These results support routine use of staging laparoscopy to achieve precise staging and more individualized management in high-risk gastric cancer.

Background and Aims: Gastric cancer (GC) remains a leading cause of cancer-related mortality, frequently diagnosed at advanced stages. High-risk features—tumor size ≥ 40 mm, cT3/cT4, nodal involvement, diffuse histology, and Borrmann type III/IV—are associated with peritoneal metastasis (PM). Staging laparoscopy with peritoneal washing (PW) is superior to conventional preoperative imaging modalities, including contrast-enhanced CT, MRI, PET/CT and endoscopic ultrasound, in detecting occult peritoneal disease. In this era of personalized medicine and expanding loco-regional strategies such as cytoreductive surgery (CRS)/Hyperthermic IntraPEritoneal Chemotherapy (HIPEC) and Pressurized IntraPeritoneal Aerosol Chemotherapy (PIPAC), accurate staging is crucial. This study assessed the impact of SL and PW in high-risk GC. Methods: We retrospectively analyzed 113 consecutive high-risk GC patients who underwent SL and PW between 2014 and 2024 at our institution. The primary endpoint was detection of PM or positive cytology (CY+). Secondary endpoints were treatment modification, eligibility for loco-regional therapy, and safety. Results: SL/PW identified PM or CY+ in 26 patients (23%), including 16 with CY+ only. None had radiologic signs of peritoneal disease. SL findings altered treatment in all cases: 21 patients (81%) with Peritoneal Cancer Index (PCI) < 6 underwent induction chemotherapy followed by CRS + HIPEC; 5 patients (PCI > 6) were spared non-therapeutic laparotomy and treated with bidirectional systemic chemotherapy and PIPAC. In 10 patients, systemic therapy was shifted from FLOT (fluorouracil, leucovorin, oxaliplatin, and docetaxel) to FOLFOX (fluorouracil, leucovorin, and oxaliplatin) ± nivolumab. No perioperative complications occurred; all patients were discharged within 24 h without delay in systemic treatment. Conclusions: SL with PW is safe and significantly improves staging accuracy in high-risk GC, enabling personalized therapeutic planning. Routine integration of SL should be considered essential in treatment algorithms to guide systemic and loco-regional strategies.