Successful treatment of metastatic extramammary Paget's disease with pemetrexed monotherapy systemically and 5-fluorouracil topically

Advanced extramammary Paget's disease does not have a standardized treatment guideline as its incidence is low and has been rarely reported in literature. Here we describe a case of metastatic extramammary Paget's disease successfully treated with topical 5-fluorouracil (5-FU) and systemic pemetrexed. The therapy was safe without any appreciable adverse effects like diarrhea, rash, neutropenia or fatigue; maintaining remission for more than 6 months. Thus, we propose 5-FU and pemetrexed as the first-line therapy for advanced extramammary Paget's disease, especially for aged patients with unresectable skin lesions.

Metastatic extramammary Paget's disease responding to weekly paclitaxel.

Metastatic extramammary Paget's disease (EMPD) is a rare cancer with no validated systemic treatment. Regimens including FECOM 5-fluorouracil (5-FU, epirubicin, carboplatin, vincristine and mitomycin C), 5-FU/cisplatin and single agent docetaxel exhibited varying levels of efficacy in case reports. A 58-year-old man with EMPD diffusely metastatic to bone presented with worsening shortness of breath, significant pancytopenia and disseminated intravascular coagulation (DIC). He was started on low-dose heparin for the DIC and weekly paclitaxel. Initially requiring almost daily transfusions, his shortness of breath improved after two doses of paclitaxel, and he became transfusion-independent after only three doses. Correlating with his disease course, the patient's prepaclitaxel carcinoembryonic antigen level of 62.1 ng/mL decreased to 7.4 ng/mL on 3-month follow-up, and he showed no progression of disease on imaging. With no validated chemotherapy regimen currently, this case can help guide consideration of paclitaxel in future treatment of metastatic EMPD.