Treatment response to eribulin and anlotinib in lung metastases from rare perianal adenoid cystic carcinoma: a case report.

Adenoid cystic carcinoma (ACC) is a rare salivary glands tumor and often displays aggressive behavior with frequent relapse and metastasis. The terminal ACC lacks standard treatment guidelines and is always accompanied by poor prognosis. Here, we report a case of rare perianal ACC who received resection and palliative adjuvant radiation. Five years later, PET-computed tomography (CT) showed perianal recurrence and multiple pulmonary metastases. Combined chemotherapy with doxorubicin, carboplatin and cyclophosphamide was applied for two cycles but ineffective. Further next-generation sequencing analysis of perianal tissue demonstrated the v-myb avian myelobastosis viral oncogene homolog and nuclear factor I/B fusion gene and two novel BCL-6 corepressor (BCOR) mutations (p.F1106Tfs*5 and p.L1524Hfs*8). The therapy was switched to eribulin and anlotinib and has been performed for eight cycles. At recent follow-ups, MRI and CT examinations revealed the diminishing perianal and pulmonary lesions. This study presented the first case of perianal ACC with multiple pulmonary metastases and particular BCOR mutations, who presented a durable response to eribulin and anlotinib, providing a potential therapeutic option for advanced refractory ACC.