Abstract 5167: Barriers to tumor mutational burden (TMB) testing in oncology care - U.S. Physician Survey
Authors: Jones Gieira , Szamreta Elizabeth , Jackson Bianca , Ning Ning , Stephens Jennifer , Hussain Arif 
Published: March 2024

Background: Genomic technologies have become increasingly available in oncology; however, barriers remain in terms of TMB use. This study aimed to identify barriers to physicians’ adoption/use of TMB testing.

Methods: A cross-sectional online survey was conducted with a representative sample of U.S. general medical, surgical, and/or gynecologic oncologists, including both users and non-users of TMB testing. Physician demographics, practice characteristics, barriers (reimbursement, knowledge, logistics), and approaches to alleviate barriers were collected. Quotas were put in place to ensure a distribution of diverse physician characteristics such as academic affiliations, geography, TMB use, etc. Descriptive analysis was conducted via SASv9.4.

Results: Three hundred physicians participated (47.6 mean years of age and 15.2 mean years in clinical practice on average; 50% medical oncologists, 31% surgical oncologists, and 19% gynecologic oncologists). Ninety percent of respondents reported using TMB testing. The most common barrier to TMB testing use was test turnaround time (All: 74.3%; TMB users: 72.3%; non-TMB users: 93.1%). Other commonly reported barriers included unawareness of corresponding therapy and/or clinical trials that may benefit a patient with mutation (All: 68.3%; users: 66.1%; non-users: 89.7%), obtaining prior authorizations (All: 65.7%; users: 62.7%; non-users: 93.1%), and difficulty obtaining a biopsy for testing (All: 57.3%; users: 57.6%, non-users: 55.2%). Increased coverage of TMB testing, access to educational content, and the establishment of minimally acceptable technical standards were reported as key approaches to increasing adoption/use of TMB testing.

Conclusions: These results suggest that challenges around reimbursement, knowledge, and logistics are key barriers to use of TMB testing for physicians and provide insights for solutions to alleviate the barriers to TMB testing in oncology.

Table 1. Barriers to TMB Test Adoption Reported by Physicians, % AllN=300 TMB userN=271 Non TMB userN=29 p-value Reimbursement Obtain prior authorizations 65.7 62.7 93.1 0.003 TMB not covered by insurance 53.7 53.5 55.2 &gt;0.99 Coverage policy refers to TMB as “experimental”/”unproven” 52.7 51.7 62.1 0.26 Insurance policy restricts genomic tests to particular lab/test provider 51.3 50.6 58.6 0.79 Knowledge/awareness Unaware of therapy/clinical trials that may benefit a patient with mutation 68.3 66.1 89.7 0.03 Unaware of approved indications for TMB 51.3 51.3 51.7 &gt;0.99 Lack of training on TMB 48.7 47.2 62.1 0.28 Logistics Test turnaround time 74.3 72.3 93.1 0.02 Difficulty obtaining biopsy 57.3 57.6 55.2 0.87 Inaccessibility to personnel/lab 49.0 48.3 55.2 0.84

Citation Format: Gieira Jones, Elizabeth Szamreta, Bianca Jackson, Ning Ning, Jennifer Stephens, Arif Hussain. Barriers to tumor mutational burden (TMB) testing in oncology care - U.S. Physician Survey [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5167.