Abstract 505: Molecular Standard of Care.

Abstract Background Molecular testing has transformed cancer care by enabling risk stratification, targeted therapy selection and improved patient outcomes. To evaluate the state of the field and ensure that molecular testing is consistently implemented in the appropriate clinical contexts, we developed a systematic framework—termed the Molecular Standard of Care (MSoC)—rooted in established guideline-based recommendations for molecular profiling. Methods Assessment of the MSoC consisted of four components: (1) Establishment of Evaluation Criteria (EC), defining the molecular information required for guideline-concordant treatment; (2) Cohort Identification, including patients with (a) newly diagnosed metastatic disease and (b) receipt of treatment at Fred Hutch; (3) Data Abstraction, involving manual chart review of relevant disease-specific data elements and (4) Evaluation Synthesis, summarizing molecular testing data to determine adherence to the MSoC. Results Four metastatic cancers (lung, colorectal, breast, and prostate) were evaluated using multiple cohort identification approaches. MSoCs were assembled. We reviewed 605 patients across 10 clinics over three months. 212 met inclusion criteria for MSoC assessment. The disease-specific MSoC criteria were met 89% across all four disease groups. Conclusions MSoC can be quantitatively described with disease-specific criteria that will evolve with progress in the field. Fred Hutch Cancer Center demonstrated high adherence to guideline-based molecular testing standards across major metastatic cancers. Future work will focus on automating MSoC evaluation to reduce manual review burden and enable real-time assessment of molecular testing adherence across patient populations. This model may serve as a scalable approach to benchmarking molecular testing adherence in academic and community cancer centers. Citation Format: Sam Phillips, Eric Collisson. Molecular Standard of Care [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 505.