Prognostic Analysis of Invasive Ductal Carcinoma of the Breast in Ethnic Minorities in Northeast China

Background Invasive ductal carcinoma (IDC) is the most common pathological subtype of breast cancer (BC). The prognosis of minority IDC in Northeast China has not been fully studied, which limits the demand for equal access to specific therapies among different ethnic groups. Methods Retrospective collection of cases from medical centers in Northeast China, gathering patients with primary IDC of ethnic minorities (aged ≥ 18 years) who visited between 2004 and 2024. Follow-up was conducted every six months. Data analysis was performed from October 2025 to November 2025. Results This study collected data from 847 relevant patients. The 5-year overall survival (OS) rate for all samples was 78.45%, and the 5-year event-free survival (EFS) rate was 64.84%. HR + HER2- cases were more likely to be diagnosed early (TNM Stage IA: 26.17%; IIA: 37.11%). HR-HER2- had the poorest overall prognosis, with a higher mean Ki-67 at diagnosis (HR-HER2-:42.81). In long-term survival, HR-HER2- and HR-HER + showed similar outcomes. Under different immunohistochemistry (IHC) conditions, the statistical significance for Manchu and Daur was not significant. The prognostic trend for Hui was no different from the overall trend. Conclusions The early detection rate of these ethnic minorities was lower than the average level of China, and the overall prognosis was worse compared to that of Chinese IDC patients. There were also significant differences in the prognostic outcomes among the five ethnic minority groups.