(B-087) Missed Opportunities for Patient Recruitment in Clinical Trials for Rare Cancers

Background: Patients with rare cancers often travel to Academic Medical Centers (AMCs) for treatment due to their complexity, yet many patients receive high-quality care in community oncology settings using multidisciplinary approaches. Natural history studies have been a bridge for rare diseases to inform clinical trial design, endpoint selection, and biomarker identification.

Objectives: This study evaluates rare cancer care in community oncology settings to assess its comparability to national trends and confirm real world data studies can inform regulatory science for rare cancers.

Methods: This retrospective natural history cohort study analyzed two rare cancer populations—Waldenström macroglobulinemia (WM), an indolent non-Hodgkin lymphoma subtype, and gallbladder cancer (GBC), a rare solid tumor—within the U.S. Oncology Network from 2014 to 2022, with follow-up through 2023. Patient characteristics were assessed using structured data from the iKnowMed electronic health record (EHR) system, while chart abstraction on a random subset (n = 200) evaluated treatment patterns and outcomes.

Results: Results showed comparable adherence to NCCN guidelines. Among 2,554 patients with WM (mean age: 72.7 years, SD: 10.1), demographics aligned with SEER data. At study conclusion, 82.1% were alive, and 5-year OS probabilities stratified by the Modified Staging System for WM (MSS-WM) ranged from 96.4% (low risk, N = 135) to 50.9% (high risk, N = 278) (p < 0.0001), validating MSS-WM’s risk stratification utility. Only 1.8% (N = 47) were enrolled in a clinical trial. In a subset of 200 patients, 78% initiated first line therapy, with 98% adhering to NCCN guidelines, primarily receiving BTK inhibitors and Rituximab-based regimens.

Among 2,019 patients with GBC (mean age: 69.4, SD: 11.4), demographics aligned with SEER data. Only 12 patients enrolled in a clinical trial. In a subset of 200, 96.5% had disease stage assigned: 56.0% (N = 108) had localized (LA: Stage 0–III, IVA) and 44.0% (N = 85) had advanced disease (ADV: Stage IVB). Surgery was performed in 90.7% of LA cases, primarily laparoscopic cholecystectomy, with 58.3% received adjuvant therapy (capecitabine 33.3%, cisplatin+gemcitabine 25.4%, and gemcitabine 17.5%), aligning with current literature. For ADV cases, 89.4% initiated first-line therapy, most commonly cisplatin+gemcitabine (57.9%).

Conclusions: Findings show community oncology settings deliver high-quality care in WM and GBC, aligning with SEER data. The low trial participation highlights a missed opportunity. Given the significant patient volume, trial sponsors should work with community oncologists to address barriers—policy, legal, or resource-related—to improve rare cancer research.