Prognostic significance of mammary Paget's disease in Chinese women: a 10-year, population-based, matched cohort study

To explore the prognostic significance of mammary Paget's disease (PD) in breast cancer (BC) patients and to investigate the association between clinical manifestation and outcome in invasive ductal carcinoma patients with PD (PD-IDC). Eighty-five patients diagnosed with mammary PD with underlying BC from 2006 to 2012 at Zhejiang Cancer Hospital were recruited. A matched group comprised 85 patients diagnosed with BC without PD. Patients were matched according to four variables: stage (0-IV), age at diagnosis (within 5 years), histologic subtype, and the year of surgery. The 74 patients diagnosed with PD-IDC were divided into three groups based on their clinical presentation. Compared with the matched group, the PD group had more HER2 positivity (