title: Metastatic Extramammary Paget's Disease of Scrotum Responds Completely to Single Agent Trastuzumab in a Hemodialysis Patient: Case Report, Molecular Profiling and Brief Review of the Literature.
abstract: Extramammary Paget's disease (EMPD) is a rare cancer. Although EMPD is usually noninvasive and treated with local therapy, once metastatic the prognosis of EMPD is poor and treatment options are limited. We report a case of a complete response to single agent trastuzumab in a hemodialysis patient with metastatic Her2/neu overexpressed EMPD of the scrotum. Molecular profiling of his case as well as 12 other EMPD and 8 mammary Paget disease (MPD) cases was completed and revealed multiple biomarker aberrations. Overexpression of Her2 was frequently noted (30%-40%) in both EMPD and MPD patients and when present can be effectively treated with Her2 targeted agents. Trastuzumab therapy can be safely utilized in a hemodialysis patient. In addition, multiple protein overexpression and loss were seen in EMPD including PD-1, PD-L1, PTEN, and AR as well as PIK3CA mutation. These findings may lead to possible therapeutic interventions targeting these pathways in a disease with few effective treatment options.
authors.affiliation: Department of Hematology/Oncology Oncology, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Barth
authors.affiliation: Department of Pathology, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA.
authors.forename: Essel
authors.initials: E
authors.lastname: Dulaimi Al-Saleem
authors.affiliation: Department of Radiology, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA.
authors.forename: Kristin W
authors.initials: KW
authors.lastname: Edwards
authors.affiliation: Caris Life Sciences, Phoenix, AZ 85040, USA.
authors.forename: Sherri Z
authors.initials: SZ
authors.lastname: Millis
authors.affiliation: Department of Hematology/Oncology Oncology, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA.
authors.forename: Yu-Ning
authors.initials: YN
authors.lastname: Wong
authors.affiliation: Department of Hematology/Oncology Oncology, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA.
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Geynisman