Clinical subtypes and survival outcomes in invasive breast cancer with Paget’s disease: A SEER population-based study.

Abstract

e12564 Background: The objective of this study was to investigate the clinicopathological characteristics, especially subtypes and survival outcomes of Invasive breast cancer with Paget's disease. Methods: 4930 patients were identified using the histopathology codes from the International Classification of Disease for Oncology third edition (ICD-O-3), from 2000 to 2019 in the Surveillance, Epidemiology, and End Results (SEER) database. Excluding 787 patients whose ICD-O-3 and TNM stages did not match, there were 663 patients with '8540/3, Paget disease, mammary', 976 patients with ‘8543/3, Paget disease and intraductal carcinoma(DCIS)’ and 2540 patients with ‘8541/3, and ‘8541/3, Paget disease and infiltrating ductal carcinoma (IDC) of breast’. ER and PR status have been available since 1990, and HER2 status since 2010. Results: Among patients with IDC and Paget's disease, 24.6% were under the age of 50 and 2.7% were male, which was higher than the other two groups. Expressions of ER and PR were higher than both groups, and HER2 expression was lower. The ratio of HR-/HER2+ subtype was also lower than the other two groups at 29.6%. ER+, Paget 43.7%, DCIS with Paget 36.4%, IDC with Paget 53.6%. PR+ Paget 21.6%, DCIS with Paget 21.7%, IDC with Paget 40.1%. HER2+ Paget 69.2%, DCIS with Paget 83.1 %, IDC with Paget 58.3%. HR-/HER2+subtype, Paget 40.7%, DCIS with Paget 49.2%, IDC with Paget 29.6%. As a result of survival analysis in patients with IDC and Paget's disease, the HR-/HER2+ subtype had shown the best prognosis in Overall Survival (OS) analysis (5year OS, HR+/HER2- 70.8%, HR+/HER2+ 74.9%, HR-/HER2- 63.7%, HR-/HER2+ 80.7% P=0.010) In the BCSS analysis, the 5-year BCSS was the best at 87.0% in the HR-HER2+ subtype, but there was no statistically significant difference. Conclusions: In IDC with Paget's disease, the distribution of subtypes is different from that of DCIS with Paget's, and HER2 expression can be considered as a favor prognostic factor. It is considered necessary to study the relationship between the loss of HER2 overexpression and invasion/progression in invasive breast cancer with Paget's disease.