Comparison of clinicopathologic characteristics of Invasive Papillary Carcinoma with Invasive Ductal Carcinoma and their survival outcome

Background: Invasive Papillary Carcinoma (IPC) of the breast is a rare breast cancer subtype. This study aimed to evaluate the clinicopathologic characteristics of IPC of the breast, its differences from Invasive Ductal Carcinoma (IDC), and their survival outcomes.Materials and Methods: The medical records of 6599 patients were retrospectively reviewed at the Breast Disease Research Center from December 1993 to December 2021. The patients were divided into two groups: IPC and IDC. The tumor size, lymph node metastasis, pathologic stage, nuclear and histological grade, hormonal receptor status, and survival were reviewed and compared between the IPC and IDC groups.Results: Of the 6599 patients, 27 had IPC, and 6572 had IDC. The mean age of patients with IPC and IDC was 58.5 and 49 years, respectively (P=0.02). Patients with IPC were more likely to have a positive node status and had a significantly higher incidence of lymphovascular invasion (14.9% for IPCs and 53.3% for IDCs, P<0.001). ER status was positive in 66.6% of IPCs and 78.1% of IDCs (P=0.23). Additionally, 62.5% of patients with IPC and 94.9% of those with IDC received adjuvant chemotherapy (P<0.001). Disease-free survival (DFS) and overall survival (OS) were better in IPC patients for stage I (5-year DFS: 69% vs. 81%, P=0.008; 5-year OS: 75% vs. 85%, P=0.001).Conclusion: IPC is a rare tumor type that presents unique clinicopathological characteristics and is associated with a higher rate of breast-conserving surgery and a favorable prognosis than IDC