The efficacy and survival impact of conventional chemotherapies for metastatic extramammary Paget's disease (EMPD) have not been fully elucidated. This study examined the long-term outcome of chemotherapy for this indication. We conducted a retrospective review of 21 patients with distant metastatic EMPD (14 patients treated with chemotherapy and 7 patients treated without chemotherapy). The response rate of chemotherapy and patient survival were statistically analyzed. Among the 14 patients treated with chemotherapy, 12, 1, and 1 patient received docetaxel, paclitaxel, and low-dose 5-fluorouracil plus cisplatin, respectively, as the first-line treatment. The response rate was 50.0% (7/14), and the disease control rate was 64.3% (9/14). The median progression-free survival (PFS) and overall survival (OS) were 16.8 and 27.9 months, respectively. Multivariate analyses revealed that chemotherapy was a significant factor for prolonged PFS (hazard ratio (HR) 0.22, p = 0.038) but not for OS (HR = 1.71, p = 0.54). Ten patients (71.4%) had severe (grade 3 or 4) hematological adverse events. Although conventional chemotherapy improved PFS, we failed to show a significantly improved OS. Considering the frequent adverse events of conventional chemotherapy, targeted therapy may become a mainstay for the treatment of metastatic EMPD.
Keywords: chemotherapy; docetaxel; extramammary Paget’s disease; metastatic extramammary Paget’s disease; survival analysis; targeted therapy.