Limited efficacy of immunotherapy in cutaneous squamous cell carcinoma arising from hidradenitis suppurativa

In this retrospective single-center study of six patients with HS-CSCC treated with immunotherapy (2021–2026), the disease control rate was 50% (partial response 17%, stable disease 33%), but control was non-durable with 83% of patients requiring subsequent treatment for disease progression and 67% dying of their HS-CSCC.

These outcomes resemble those of chronic-wound CSCCs and suggest that HS-CSCC may have similar biology with limited immunotherapy benefit. Surgical resection should be prioritized when feasible, reserving immunotherapy for unresectable disease. Included here are supplemental clinical images that document the patients' treatment course, with a focus on their disease response to immunotherapy (black box) and treatment approaches.