Successful Treatment of Metastatic Primary Cutaneous Adnexal Carcinoma With a PD-1 Inhibitor

Area of Science:

• Oncology
• Dermatology
• Immunotherapy

Background:

• Metastatic cutaneous adnexal carcinomas lack established standard treatments.
• Primary cutaneous adnexal carcinoma is a rare group of skin cancers with limited therapeutic options when metastatic.

Observation:

• A patient with metastatic primary cutaneous adnexal carcinoma presented with low tumor mutation burden, microsatellite stability, and high PD-L1 gene expression.
• The patient received anti-programmed cell death protein 1 (anti-PD-1) therapy.

Findings:

• The patient experienced significant radiographic response and a decrease in circulating tumor DNA.
• Durable clinical benefit was observed following anti-PD-1 therapy.

Implications:

• Immune checkpoint inhibitors, such as anti-PD-1 therapy, show promise for treating rare metastatic adnexal carcinomas.
• Further research is required to identify predictive biomarkers for immune checkpoint inhibitor efficacy in advanced non-melanoma skin cancers.