Implementation of genetic counseling recommendations in an MTB setting.

Abstract

68 Background: Genetic counseling (GC) is a critical component of precision oncology and personalized cancer care, informing on targeted treatment strategies, cancer surveillance, and familial risk. The Molecular Tumor Board (MTB) serves as a multidisciplinary forum where GC recommendations are generated. Effective communication between the MTB and GC team ensures timely referral and follow-up. This study aimed to determine qualifiers for GC recommendations and quantify the patients who subsequently underwent germline testing (GT). Methods: We analyzed GC recommendations based on somatic testing and review of personal and family cancer histories for patients reviewed at the MTB from May 2021 to December 2025. Recommendations for GC were generated in alignment with institutional protocols informed by the guidelines proposed by Li et al., 2020 in Genetics in Medicine and McVeigh et al., 2025 in J Med Genet, taking variant allele frequency (VAF) and gene of interest actionability into account. Recommendations were communicated to treating oncologists for clinical judgement and appropriate referrals. Recommendations were assigned a descriptive category for analysis. GT outcomes were obtained through chart review to assess implementation of recommendations. Results: Of the 5405 unique patients reviewed by the MTB, 1764 were identified as patients that qualified for GC. Of these patients, 993 (56.3%) underwent GT with 221 (12.5%) completing GT within Inova following recommendations. Most patients met more than one criterion for GT, with diagnosis, according to relevant NCCN guidelines, being the most common driver for recommendation. Of the 221 patients who completed GT at Inova following MTB review, 45 patients were found to have pathogenic variants in genes associated with an autosomal dominant hereditary cancer susceptibility and 5 were found to be carriers for autosomal recessive cancer susceptibility conditions. Pathogenic variants in the BRCA2 gene were most common among these patients. Conclusions: Effective collaboration between clinical providers and GC teams is essential to ensure that patients are appropriately evaluated for GC needs. The MTB serves as a structured forum that facilitates coordinated decision-making across these disciplines. Further investigation is warranted to understand the factors influencing providers’ decisions to concur with referral requests for follow-up GC following MTB review, as well as to analyze the evolution in GC recommendations as somatic testing has become more widespread. GC recommendations by reason. Reason # Patients Somatic Mutation of Interest or Somatic Mutation at High VAF (≥30%) 125 (7.1%) Personal Diagnosis (Including Early Onset Disease and/or Multiple Primaries) 420 (23.8%) Family History 99 (5.6%) Combination of Qualifiers 167 (9.5%) Already Contacted/ Referred 384 (21.8%) Already Seen/Tested 557 (31.6%) Additional Testing Recommended 12 (0.7%) Total 1764