Stable Disease Achieved with Sequential Immunochemotherapy and Anti-Angiogenic TKI in Recurrent Metastatic Hidradenocarcinoma: A Case Report and Literature Review

Hidradenocarcinoma is a rare and highly aggressive malignancy with limited therapeutic options. This report describes the clinical course and treatment response of a patient with recurrent metastatic hidradenocarcinoma treated with sequential immunochemotherapy combined with anti-angiogenic therapy, with the aim of providing further insight into potential treatment strategies for this rare malignancy.

A 60-year-old male initially presented in 2020 with scrotal erythema and was diagnosed with hidradenocarcinoma after surgery. Despite surgical treatment, he developed recurrent disease with diffuse metastases. First-line chemoimmunotherapy (sintilimab, cisplatin, 5-fluorouracil; six cycles) achieved a progression-free survival (PFS) of 6 months. Following disease progression, second-line therapy (toripalimab, nab-paclitaxel, anlotinib; eight cycles) was administered, resulting in sustained stable disease with a subsequent PFS of 8 months. Radiotherapy was used for brain metastases. The total follow-up duration exceeded 4 years until the patient was lost to follow-up in December 2024.

This case suggests that sequential programmed death-1 (PD-1) blockade-based immunochemotherapy combined with anti-angiogenic therapy may provide clinically meaningful disease control in metastatic hidradenocarcinoma, even in the setting of low programmed death-ligand 1 (PD-L1) expression and microsatellite stability. Our findings support a potential role for immunotherapy in sweat gland carcinomas and highlight the importance of individualized multimodal treatment strategies for this rare malignancy. Further studies are needed to identify predictive biomarkers and establish optimal therapeutic approaches.