The knowledge and skills required for the onco-rheumatologist: Study of four-year consultation records of a high-volume cancer centre.

OBJECTIVES

Onco-rheumatology, the intersection of oncology and rheumatology, is an emerging field requiring further definition. This study aimed to identify the knowledge and skills essential for rheumatologists in clinical oncology.

METHODS

We retrospectively reviewed consultations with the onco-rheumatology department of a high-volume tertiary cancer centre in Japan from January 2020 to December 2023.

RESULTS

We analysed 417 consultations. The most common consultation (229, 55%) was related to immune checkpoint inhibitor-induced immune-related adverse events (irAEs). Of the 238 irAEs in 185 patients, 15% were rheumatic and 85% were nonrheumatic (e.g. hepatobiliary toxicities, colitis). Approximately 25% of nonendocrine irAEs were refractory/relapsing, requiring second-line therapy (e.g. mycophenolate mofetil, biologics, immunoglobulin). In addition to irAE consultations, 137 (33%) consultations were about possible rheumatic diseases. The final diagnosis often related to cancer treatment, such as granulocyte colony-stimulating factor-related aortitis (15 patients, 11%), olaparib-related erythema nodosum (10 patients, 7.3%), and surgical menopause-related arthralgia (10 patients, 7.3%). Five patients (3.6%) were diagnosed with autoinflammatory bone disease mimicking bone tumours.

CONCLUSIONS

Onco-rheumatologists are expected to play a central role in the management of a wide range of irAEs, not limited to rheumatic irAEs. They must also manage rheumatologic manifestations during cancer treatment and rheumatic diseases that mimic tumours.