P-329: Diagnostic challenges across the multiple myeloma pathway: perspectives of primary care physicians and orthopedic specialists

Introduction: Multiple myeloma (MM) is challenging to diagnose due to its non-specific symptoms. Patients often see multiple physicians before diagnosis, namely primary care physicians (PCPs), but also orthopedic specialists (OrS), nephrologists, rheumatologists and internal medicine physicians among others. One UK study reported that MM has the highest number of patients seeing >3 PCPs before specialist referral than any other reported cancer. The aim of this research is to better understand the barriers to rapid and accurate diagnosis of MM, to optimize the diagnostic pathway.

Methods: Double-blind, virtual, 1-hour interviews were conducted in May 2024. Interviewees were required to have knowledge of MM and included 8 PCPs and 7 OrS from the US (9), France (2) and Australia (4). Interviews covered three themes: likelihood to suspect MM, diagnostic testing and referral patterns, and educational needs. Key words were used to identify concepts discussed and quantify the qualitative data.

Results: All interviewees noted that MM is rare and is not front of mind for differential diagnoses. 100% of PCPs reported to rarely encounter MM, compared with 14% of OrS. Lower back pain, weight loss, and fatigue were identified as symptoms of MM by all interviewees. Clinical indicators that would raise suspicion of MM were anemia or renal function reported by PCPs (62% and 38% respectively); and atraumatic or multiple fractures reported by OrS (86% and 43% respectively).

On suspicion of MM, 73% of interviewees reported conducting standard blood tests (complete blood count, kidney function and calcium levels) and all OrS reported conducting imaging (X-rays, MRIs, or CT scans). 73% of interviewees also reported to order electrophoresis alongside standard blood tests, however, only 13% ordered the guideline-based approach to MM diagnosis (electrophoresis and light chain assay tests). Further, 80% of interviewees reported discomfort with interpreting MM-specific blood test results, requiring input from hematologists.

All interviewees reported receiving no MM-specific training outside of medical school. 57% of OrS gained familiarity of MM from fellowships and residency experience. OrS stated they were more likely to refer patients who ultimately received a MM diagnosis than PCPs. Referral criteria guidance and testing protocols were identified as potential tools to support education among 67% of interviewees.

Conclusions: Disease rarity and a lack of local and national guidance makes the diagnosis of MM complex, both in suspicion and in confirmation. Targeted education on MM symptoms and testing guidance for non-MM specialists may improve the timely and accurate diagnosis of MM by supporting physicians to identify MM sooner in the diagnostic pathway. Tools to aid non-specialist diagnosis and referral of MM are in development, however, further research is needed to draw robust conclusions.