PD-1 blockade combined with anlotinib and bicalutamide for metastatic primary cutaneous apocrine carcinoma: a case report and literature review

Yuqi Jin, Linglin Fu, X Leng, Yinuo Tan

Background Primary cutaneous apocrine carcinoma (PCAC) is a rare malignant adnexal tumor with substantial diagnostic complexity and no established systemic therapy standard for advanced disease.Evidence for endocrine therapy, targeted therapy, and immune checkpoint inhibitors is limited to small series and case reports. Case presentation A patient presented with a pruritic erythematous plaque on the left chest wall that progressively enlarged over one year. Skin biopsy and subsequent pathology consultation demonstrated invasive adenocarcinoma involving the dermis and subcutaneous tissue. Immunohistochemistry supported PCAC (CK7+, GATA3+, AR strongly positive, and patchy GCDFP-15 positivity), and a left axillary lymph node confirmed metastatic carcinoma. Whole-body 18 F-FDG PET/CT revealed extensive metastatic disease involving multiple lymph node stations, lung, pleura, and multiple bones, precluding upfront surgery. The patient received systemic therapy with serplulimab (300 mg intravenously every 3 weeks) plus anlotinib (10 mg orally once daily, days 1–14 of a 21-day cycle) and concomitant bicalutamide (50 mg orally once daily). After two cycles, CT imaging showed partial reduction in pulmonary nodules and mediastinal lymphadenopathy, with thinning of the chest wall lesion and resolution of a small pleural effusion. Subsequent follow-up demonstrated continued clinical improvement of the chest wall lesion and sustained radiological disease control, without new rapidly progressive visceral lesions. No clinically significant adverse events or notable laboratory toxicities were observed during treatment and follow-up. Conclusion This case illustrates a feasible combination approach for widely metastatic PCAC using PD-1 blockade, anti-angiogenic therapy, and anti-androgen treatment, with clinical and radiographic improvement and favorable tolerability during follow-up. Prospective data are needed to clarify patient selection and define optimal systemic strategies for advanced PCAC.