Diagnostic accuracy of general dermatologists and supportive oncodermatologists for biopsied cutaneous immune-related adverse events.

Purpose: Supportive oncodermatology has been shown to improve several aspects of care for patients with cancer, but research showing improved diagnostic accuracy as a benefit of supportive oncodermatology is largely lacking. We thus aimed to evaluate different dermatologist groups' diagnostic accuracy for heterogenous cutaneous toxicities, using cutaneous immune-related adverse events (cirAEs) from immune checkpoint inhibitors (ICIs) as a test model.

Methods: Billing/requisition codes were used to identify patients who initiated programmed death-1/ligand-1 (PD-1/PD-L1) ICIs between 2010 and 2019 at Dana-Farber Cancer Institute/Brigham and Women's Hospital/Massachusetts General Hospital and underwent a subsequent skin biopsy. For each biopsied cirAE, pre-biopsy clinical diagnoses and post-biopsy clinico-pathologic diagnoses were retrospectively obtained from the medical record. Each biopsy-ordering dermatology provider was categorized as a general dermatologist or supportive oncodermatologist on the basis of providing clinical care within a cancer-center or attending on a hospital/clinic service dedicated to anti-cancer drug-related skin toxicities.

Results: Of 4,183 patients who initiated anti-PD-1/PD-L1 therapy between 2010 and 2019, 101 (2.4%) patients collectively had 104 biopsied cirAEs. In more than one-third of all reviewed biopsied cirAEs (n = 39, 37.5%), histopathology results frequently led to revision of the pre-biopsy clinical diagnosis. The rate of initial cirAE misclassification amongst supportive oncodermatologists was significantly lower than that amongst general dermatologists (18/66, 27.3% vs. 21/38, 55.3%; Fischer's-exact-test p = 0.006).

Conclusion: Experienced supportive oncodermatologists may benefit patient care through increased diagnostic accuracy for skin toxicities from ICIs. Collectively, these results underscore that both skin biopsy from any dermatology provider and oncodermatology referral (where available) are valuable resources that should be integrated into supportive cancer care.