Data Show Inconsistent Biomarker Testing in Gastric/GEJ Cancer Care

"...The management of evolving logistics for testing and related decision-making, including multidisciplinary care coordination, can be challenging, especially in community clinics,” the study authors wrote.

A majority of oncology care providers in a community setting did not report the use of recommended biomarker testing for patients with gastric and gastroesophageal junction (GEJ) cancers, according to data presented at the 2025 ASCO Gastrointestinal Cancer Symposium.

“Although most oncology teams reported use of some form of biomarker testing in treatment of [gastric or GEJ] cancer, testing was inconsistent and not as comprehensive as currently recommended,” wrote researchers in their poster.

In a recent study which surveyed 60 oncology care providers from community oncology practices, 22% of participants reported ordering biomarker testing for every patient with advanced gastric or GEJ cancer. Fewer than half of participants reported testing for TMB (43%), BRAF p.V600E (32%), microsatellite instability (MSI; 47%), and mismatch repair (MMR; 48%), and fewer than a quarter said they tested for RET (13%), CLDN 18.2 (5%), FGFR2 (18%), or NTRK1/2/3 (22%). In contrast, tests for the biomarkers HER2 and PD-L1 were reported in 67% and 62% of pathology reports, respectively.

Challenges in Biomarker Testing

Those surveyed reported their challenges with biomarker testing, including prioritizing testing for limited tissue (38%), determining whether to begin treatment after receiving molecular testing results (35%), and optimizing specimen collection for molecular testing (27%). Turnaround time for testing, uncertainty interpreting biomarker results, and inconsistent or infrequent multidisciplinary tumor boards were also concerns reported by providers.

Twelve percent of providers reported not participating in multidisciplinary tumor boards at all, 23% reported they participate less frequently than every other month, 12% said they participate every other month, 21% said they participate once or twice a month, and 16% said they participate weekly.

In addition, 23% of providers surveyed reported feeling very or extremely comfortable, corresponding to scores of 4 or 5 on a 5-point scale, with using biomarker testing results to inform treatment decisions.

Providers reported that the most crucial steps to incorporating biomarker testing into workflows were improving the test ordering process (47%), decreasing testing turnaround time (42%), and standardizing panels for biomarker testing (40%), as noted in the poster’s abstract.

Survey Details

Of the 60 oncology team members that completed the surveys, there were 23 nurses, 12 medical or surgical oncologists, and 10 advanced practice providers (APPs). Other providers surveyed included 1 pathologist, 2 pharmacists, and 12 other related care providers.

The survey was followed by a 63-person summit, during which providers discussed plans to address the issues with biomarker testing in patients with gastric and GEJ cancer. The most common concerns providers planned to focus on were incorporating multidisciplinary tumor boards to discuss cases from their practices (44%), not knowing what biomarker/molecular testing to order (31%), and keeping up with the latest guideline recommendations and recent clinical trial data (31%).

The National Comprehensive Cancer Network recommends testing for MSI and MMR biomarkers for newly diagnosed cases of gastric and GEJ cancers along with HER2 and PD-L1 for locally advanced unresectable, metastatic, or recurrent gastric and GEJ cancers.

“However, the management of evolving logistics for testing and related decision-making, including multidisciplinary care coordination, can be challenging, especially in community clinics,” the study authors wrote.

Reference

Strickland MR, Sidiropoulos N, Salgado AMV, et al. Precision medicine and multidisciplinary care in gastric and gastroesophageal junction (G/GEJ) cancers: challenges and practice gaps in community cancer clinics. J Clin Oncol. 2025;43(suppl 4):385. doi:10.1200/JCO.2025.43.4_suppl.385