Assessing the value of multiple molecular tumor board reviews for sequential next-generation sequencing in patients with solid-tumor malignancies.

e23340 Background: Multi-disciplinary molecular tumor boards (MTB) are shown to improve clinical outcomes in various malignancies. Sequential next-generation sequencing (NGS) is widely performed at time of recurrence, leading to multiple MTB reviews. This study assessed the clinical benefit of multiple molecular tumor board reviews for sequential NGS testing. Methods: A retrospective cohort review was performed to compare patients reviewed once at a single-institution MTB and those reviewed multiple times for the same diagnosis with sequential NGS testing between January 2016 and December 2023. Demographics were compared, and regression analysis was performed. Medical record review was performed for patients reviewed multiple times. Overall survival analysis was performed. Results: Overall, 3702 patients were included, 3446 (91.6%) reviewed once and 256 (8.4%) were reviewed multiple times. Predictors of multiple MTB reviews included patient age less than 65 years (OR 1.56 95% CI 1.17-2.08, p = .003), recurrent disease at time of review (OR 4.71, 95% CI 2.03-10.93, p < .0001), and primary diagnosis of breast (OR 4.59, 95% CI 1.7-12.4, p = .0003), gynecologic (OR 3.6, 95% CI 1.37-9.47, p = .003), colorectal (OR 4.12, 95% CI 1.59-10.7, p = .0001), or other gastrointestinal cancer (OR 3.57, 95% CI 1.37-9.32, p = .002). About half of those reviewed once (52.7%) and multiple times (49.2%) had an actionable finding on NGS report ( p = 0.28). Patients with one MTB review had a significantly higher proportion of immunotherapy recommendations (30.4% vs 18.4%, p < 0.0001). Those reviewed multiple times were more likely to be recommended targeted therapy (38.7% vs 31.4%, p = 0.02). Of patients reviewed multiple times with treatment data available, 50% received the recommended treatment between their first and second review, and this persisted between reviews two and three. Mean time on recommended targeted therapy for patients reviewed multiple times was 8.24 months (SD 9.34, range 0.07-42.4), and mean time on recommended immunotherapy was 7.02 months (SD 9.47, range 0.1-39.2). For those with multiple reviews who had actionable findings, the most common actionable findings were PD L1 status (n = 24, 19.1%) and tumor mutational burden (TMB), (n = 23, 18.3%). Patients with multiple MTB reviews had a 30% lower risk of death compared to those reviewed once, even after controlling for primary site, age, presence of actionable NGS findings, and stage at diagnosis (HR = 0.7, 95% CI: 0.55-0.89, p-value = 0.004). Conclusions: Sequential NGS testing identifies similar rates of actionable mutations, and patients reviewed multiple times at MTB often stay on recommended therapy for over half a year. This study is the first to show an overall survival advantage to multiple MTB reviews and indicates that age less than 65 years, primary site, and recurrent disease predict multiple MTB reviews.