Outcomes of Conversion Gastrectomy After Neoadjuvant Chemotherapy in Metastatic Gastric Cancer

Authors
Siew Fung Hau, Shannon Melissa Chan, Lai Ying Leung, Hon Chi Yip, Stephen Ka Kei Ng, Anthony Yuen Bun Teoh, Enders Kwok Wai Ng, Philip Wai Yan Chiu

Affiliations
Department of Surgery, The Chinese University of Hong Kong, Hong Kong S.A.R., China

Introduction
Metastatic gastric cancer is considered as stage IV disease and was treated with palliative chemotherapy in the past. There is increasing evidence that conversion gastrectomy after chemotherapy improves survival. The aim of this study is to review the outcomes of patients with metastatic gastric cancer who had undergone gastrectomy after chemotherapy.

Methods
In this retrospective cohort study, propensity score matching analysis was performed to minimizes selection bias. All patients were included who suffered from gastric cancer with metastasis and had undergone chemotherapy from Jan 2020 to Dec 2023 in Prince of Wales Hospital, Hong Kong. Patients’ demographics, primary tumor characteristics, site and extent of metastasis, type of neoadjuvant therapy, response after systemic therapy, operative details, recurrence and death were recorded.

Results
Of 114 individuals who met study criteria, 25 underwent conversion gastrectomy and 89 underwent systemic therapy alone without surgery. Propensity sore matching resulted in 22 matched pairs for further analysis. After matching, variables were comparable between the two groups including the age, sex, performance status, site of primary tumor, CPS score, type of systemic therapy (chemotherapy; target therapy; immunotherapy), tumor response rate, extent of metastasis (Oligometastasis or not; number of organ-system involved by metastasis). Median survival time were 39.0 months for the surgery group and 14.0 months for the palliative group. (Logrank P = 0.037). Median disease-free survival time was 19.0 months for the surgery group.

Conclusion
Conversion gastrectomy after systemic therapy for patients with gastric cancer and oligometastasis showed promising results in selected patients. Conversion gastrectomy can be considered as a treatment option in young patients with good surgical risk.