The European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with gastric cancer (GC), published in late 2022 and the updated ESMO Gastric Cancer Living Guideline published in July 2023, were adapted in August 2023, according to previously established standard methodology, to produce the Pan-Asian adapted (PAGA) ESMO consensus guidelines for the management of Asian patients with GC. The adapted guidelines presented in this manuscript represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with GC representing the oncological societies of China (CSCO), Indonesia (ISHMO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO), coordinated by ESMO and the Japanese Society of Medical Oncology (JSMO). The voting was based on scientific evidence and was independent of the current treatment practices, drug access restrictions and reimbursement decisions in the different Asian regions represented by the 10 oncological societies. The latter are discussed separately in the manuscript. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with GC across the different regions of Asia, drawing on the evidence provided by both Western and Asian trials, whilst respecting the differences in screening practices, molecular profiling and age and stage at presentation. Attention is drawn to the disparity in the drug approvals and reimbursement strategies, between the different regions of Asia.

Aim: To determine the association between sarcopenia and prognosis in patients with metastatic gastric cancer (mGC) receiving chemotherapy. Patients and Methods: Our study retrospectively evaluated 231 consecutive Japanese patients with mGC who commenced first-line chemotherapy at our Institution between January 2013 and December 2015. Muscle loss during chemotherapy was defined as a ≥10% reduction in the skeletal muscle index and was evaluated for its association with time to treatment failure (TTF) and overall survival (OS). Results: Of 118 patients, 89% had baseline sarcopenia and 31% developed muscle loss. Muscle loss was significantly associated with shorter TTF and OS and was an independent prognostic factor for both these parameters; poor performance status and poorer differentiation on histology were also significant predictors of shorter OS. However, muscle loss was not significantly associated with increased grade 3 or higher toxicities. Conclusion: Muscle loss during chemotherapy negatively affected survival among patients with mGC.

Gastric cancer treatments are evolving rapidly. For example, immune checkpoint inhibitors, especially those that target PD-1 or PD-L1, have long-term efficacy in a subset of gastric cancer patients, and are currently the first-line therapy. Immunotherapies approved for use in untreated gastric cancer patients include monotherapy and chemotherapy-immunotherapy combinations. Major clinical trials have reported efficacy and safety data suggesting that PD-L1 expression is important for regimen selection, although other biomarkers, clinicopathologic factors, and patient preference might also be relevant in other situations. Currently, several novel biomarkers and therapeutic strategies are being assessed, which might refine the current treatment paradigm. In this review, we describe the current treatment regimens for patients with gastric cancer and detail the approach we use for the selection of first-line immunotherapy regimens.

PD-L1 immunohistochemistry comparison of 22C3 and 28-8 assays for gastric cancer Yukiya Narita, Eiichi Sasaki, Toshiki Masuishi, Hiroya Taniguchi, Shigenori Kadowaki, Seiji Ito, Yasushi Yatabe, Kei Muro

Background: It remains unclear whether human epidermal growth factor receptor 2 (HER2) status is an outcome-associated biomarker independent of known prognostic factors for metastatic gastric cancer. Moreover, there are few reports about nomograms in inoperable locally advanced or metastatic gastric cancer (AGC), although several studies have been reported regarding other cancer types. This retrospective study aimed to develop nomograms that combine HER2 status and other prognostic factors to predict the survival outcomes of AGC patients starting first-line treatment. Methods: In this study, 838 consecutive AGC patients starting first-line chemotherapy at the Aichi Cancer Center Hospital (ACC) were included to establish the nomograms that calculated the predicted probability of survival at different time points, 6 months and 1 and 2 years for overall survival (OS) and 3 and 6 months, and 1 year for progression free survival (PFS). Nomograms were independently validated with 269 consecutive AGC patients at the Cancer Center Hospital (SCC) who underwent first-line chemotherapy. The discriminatory ability and accuracy of the models were assessed using Harrell’s c-index. IHC3+ or IHC2+/ISH+ tumors were defined as HER2 positive. Results: At a median follow-up of 12.3 (ACC) and 11.6 (SCC) months, the median OS was 12.5 and 12.4 months (P=1.00), and the median PFS was 4.8 and 5.8 months (P=0.03), respectively. The nomograms showed good C-index values: OS was respectively 0.688 and 0.576 and PFS was respectively for 0.643 and 0.544. Conclusions: The nomograms including HER2 status as covariate are crucial determinants of clinical care.