From Control to Conversion: Optimizing Systemic Therapy for Curative-Intent Conversion Surgery in Metastatic Gastric...

Area of Science:

• Oncology
• Surgical Oncology
• Gastroenterology

Background:

• Conversion therapy aims for curative resection in initially unresectable metastatic cancers.
• Advances in systemic therapies (targeted agents, ICIs) have revitalized interest in conversion therapy for metastatic gastric cancer (GC).

Purpose of the Study:

• To review international guidelines and expert consensus on conversion therapy for metastatic GC.
• To emphasize the role of systemic therapy, biomarker-driven strategies, and surgical timing.

Main Methods:

• Review of key consensus statements (Bertinoro, OMEC, KINGCA WEEK 2024).
• Analysis of pivotal studies from cytotoxic, targeted, and immunotherapy eras.
• Focus on regimen selection, treatment duration, and prognostic factors for surgical outcomes.

Main Results:

• Conversion surgery is not standard but considered for selected patients showing major response to systemic therapy.
• R0 resection following conversion therapy shows median overall survival of 24-36 months (cytotoxic era) and >48 months (ICI/targeted era).
• Optimal timing involves ~6 months preoperative systemic therapy, R0 resection, and up to 1 year of postoperative maintenance therapy.

Conclusions:

• Conversion surgery is an extension of effective systemic therapy, not a replacement.
• A biology-driven, multidisciplinary approach integrating response assessment and prognostic factors is key for potentially curative management of metastatic GC.