EPIDEMIOLOGY, RISK FACTORS AND BURDEN ASSOCIATED WITH PERITONEAL METASTASES (PM) IN GASTRIC CANCER (GC): A SYSTEMATIC LITERATURE REVIEW (SLR)
Author(s)
Raghav Sundar, MD, PhD1, John Hays, MD, PhD2, Jaewon Hyung, MD3, Wenxi Tang, MSc4, Po-Ya Chuang, MHA5, Jacqlyn Riposo, MBA5, Kaitlyn Esselman, MHS5, Lin Zhan, MSc4.
1Yale School of Medicine, New Haven, CT, USA, 2The Ohio State University, Columbus, OH, USA, 3Asan Medical Center University of Ulsan College of Medicine, Seoul, Korea, Republic of, 4BeOne Medicines, Emeryville, CA, USA, 5Real Chemistry, New York, NY, USA.
1Yale School of Medicine, New Haven, CT, USA, 2The Ohio State University, Columbus, OH, USA, 3Asan Medical Center University of Ulsan College of Medicine, Seoul, Korea, Republic of, 4BeOne Medicines, Emeryville, CA, USA, 5Real Chemistry, New York, NY, USA.
OBJECTIVES: GCPM has been associated with poor prognosis. With recent approvals of novel therapies, this SLR aimed to assess contemporary evidence on epidemiology and burden associated with GCPM.
METHODS: PubMed®, Embase®, and Cochrane® databases were searched for studies published between 8/2021 to 9/2025 that reported epidemiology, risk factors, treatment patterns, and outcomes of GCPM. Studies focusing solely on metachronous PM, clinical trials, sample sizes <30, and limited to surgical outcomes were excluded.
RESULTS: Of 1,105 studies identified, 33 were included after screening. Among GC patients, PM prevalence was 43% and incidence was 34%. Identified risk factors included younger age, signet ring cell carcinoma, diffuse-type histology and T4 stage, and biomarkers such as circulating tumor cells, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio. Among studies reporting treatment patterns (n=10), systemic chemotherapy was the most frequently reported treatment. Immunotherapy and targeted therapy were reported in a smaller proportion of patients, typically in later lines of therapy or in combination with first-line chemotherapy. Overall survival (OS) (n=24) and progression-free survival (PFS) (n=7) varied substantially based on patient characteristics. Patients with resectable disease had median OS (mOS) up to 37 months, whereas unresectable disease mOS ranged from 2 to 10 months. Median PFS ranged from 11 to 26 months for resectable patients and 1 to 5 months for unresectable patients. Few studies reported quality of life or economic outcomes.
CONCLUSIONS: This SLR identified a high frequency of PM among patients with GC and poor outcomes, particularly in unresectable disease. Despite the availability of immunotherapies and targeted therapies, most included studies evaluated systemic chemotherapy, with very limited real-world evidence on novel treatments and sparse reporting of humanistic and economic burden. These findings confirm the substantial unmet need in GCPM and highlight the need for updated research to understand whether and how novel therapies are improving patient outcomes.
METHODS: PubMed®, Embase®, and Cochrane® databases were searched for studies published between 8/2021 to 9/2025 that reported epidemiology, risk factors, treatment patterns, and outcomes of GCPM. Studies focusing solely on metachronous PM, clinical trials, sample sizes <30, and limited to surgical outcomes were excluded.
RESULTS: Of 1,105 studies identified, 33 were included after screening. Among GC patients, PM prevalence was 43% and incidence was 34%. Identified risk factors included younger age, signet ring cell carcinoma, diffuse-type histology and T4 stage, and biomarkers such as circulating tumor cells, neutrophil-to-lymphocyte ratio, and platelet-to-lymphocyte ratio. Among studies reporting treatment patterns (n=10), systemic chemotherapy was the most frequently reported treatment. Immunotherapy and targeted therapy were reported in a smaller proportion of patients, typically in later lines of therapy or in combination with first-line chemotherapy. Overall survival (OS) (n=24) and progression-free survival (PFS) (n=7) varied substantially based on patient characteristics. Patients with resectable disease had median OS (mOS) up to 37 months, whereas unresectable disease mOS ranged from 2 to 10 months. Median PFS ranged from 11 to 26 months for resectable patients and 1 to 5 months for unresectable patients. Few studies reported quality of life or economic outcomes.
CONCLUSIONS: This SLR identified a high frequency of PM among patients with GC and poor outcomes, particularly in unresectable disease. Despite the availability of immunotherapies and targeted therapies, most included studies evaluated systemic chemotherapy, with very limited real-world evidence on novel treatments and sparse reporting of humanistic and economic burden. These findings confirm the substantial unmet need in GCPM and highlight the need for updated research to understand whether and how novel therapies are improving patient outcomes.
Conference/Value in Health Info
2026-05, ISPOR 2026, Philadelphia, PA, USA
Value in Health, Volume 29, Issue S6
Code
EPH72
Topic
Epidemiology & Public Health
Disease
No Additional Disease & Conditions/Specialized Treatment Areas, SDC: Oncology