Investigating Breast Cancer Metastatic Trends, Types, and Their Common Organs of Metastasis

Background and Objectives: Breast cancer (BC) is the most prevalent cancer in women all over the world, and the leading cause of death is its metastasis. This study aimed to investigate the metastatic trends, molecular subtypes, and common organs of metastasis among women with BC in Sulaimaniyah, Iraq.Patients and methods: A prospective, descriptive, cross-sectional study was conducted from January to May 2025 at two major oncology centers in Sulaimaniyah, Iraq. A total of 200 women with histopathologically confirmed metastatic BC were enrolled. Data on sociodemographic, clinical, pathological, and molecular characteristics were collected through structured interviews and review of medical records. Results: The majority of patients were aged 45–64 years (n=106, 53%) and presented with invasive ductal carcinoma (n=183, 91.5%). Luminal A was the most common molecular subtype (n=136, 68%), and most patients had high Ki-67 levels (>20%). Bone was the predominant site of metastasis (n=75, 37.5%), followed by the lung (n=40, 20%) and liver (n=18, 9.0%). Most metastatic events occurred within the first year after diagnosis. Advanced-stage disease and axillary lymph node involvement were common at presentation (n=197, 98.5%). The overall survival rate was 91.5%.Conclusions: Bone is the most frequent site of metastasis in BC patients, with luminal A subtype predominating. The importance of high-quality screening and the timely formulation of intervention measures is evident given the early metastatic development and advanced stage of presentation.