Supplementary Material for: Metastatic Syringocystadenocarcinoma Papilliferum treated with Enzalutamide: a case-report and a review of the literature

Syringocystadenocarcinoma papilliferum (SCACP) is a rare malignancy of the elderly originating from apocrine adnexal glands, mostly developing in the head and neck district. To date, there is no established treatment for metastatic SCACP, leaving affected patient with small therapeutic opportunities. Herein, it is described the case of a 70 years old man affected by metastatic SCACP treated with three different sequential therapy lines: carboplatin plus paclitaxel, epirubicine and an off-label protocol with Enzalutamide, achieving 41 months overall survival (OS). Off-label Enzalutamide treatment has been justified by androgen receptor expression by SCACP cells, a common feature of apocrine glands derived tumors. Interestingly, SCACP demonstrated to be responsive to Enzalutamide treatment, even though the patient precociously stopped the treatment due to severe toxicity. In conclusion, this case represents the first evidence of hormonotherapy administration in a SCACP patient, possibly providing the base for a new therapeutic opportunity for this rare malignancy.