Breast cancer characteristics in relation to age at diagnosis, in a leading oncology institution in Cartagena, Colombia

Background: Breast cancer is a major public health problem, it is the most commonly diagnosed malignant neoplasia, and the leading cause of cancer deaths in women, worlwide and also in Colombia. .Women living in transitioned countries have considerably higher incidence rates compared with those in transitioning countries, this reflects a higher prevalence of some reproductive risk factors, including early age at menarche. There is scarce knowledge about the clinical characteristics of breast cancer patients living in developing countries. This study, evaluated and compared the characteristics of breast cancer cases in older, middle aged, and young women, treated at an oncology center in Colombia.Objective: To describe the characteristics of breast cancer cases treated in a leading oncology institution in Cartagena, Colombia, and their association with the age at the time of diagnosis. Methods: A database of women treated for breast cancer at a leading oncology institution in Cartagena, Colombia, between January 2010 and December 2024, was retrospectively analyzed. Were compared clinical and histopathological characteristics between women aged 20 to <40, 40 to <65, and ≥65 years. Clinical information was collected: age at menarche, parity, stage at diagnosis and histological type. Results: Were included 698 patients with a mean age at diagnosis of 56.06 years (SD=±13.16, 95%CI= 55.08-57.04). Most of cases were middle-aged women (40 to 65 years= 63.33%) with a high proportion of cases in older women (>65 years= 24.21%), and a smaller number of young women (20 to 39 years=10.45%). Were observed significant associations between age at diagnosis and age of menarche (mean=12.09 years, SD=±1.69, 95%CI= 12.74-13.03), (p=0.0001, t test); and, between age at diagnosis and number of pregnancies (mean=3.25, SD=±2.13, 95%CI= 3.08-3.42), (p=0.0001, t test). Most of the tumors (84.45%) were ductal carcinomas, followed by lobular carcinomas (6.3%), and other histological types in small proportion, a statistically significant difference was found between histological type and age (p=0.041, Fisher´s test). Of the patients, 57.11% presented with locally advanced disease (stage II), only 5% presented with metastatic disease, and there was a significant association between age and clinical stage at diagnosis (p=0.0099, X2). Conclusion: These findings highlight significant associations between age at diagnosis, reproductive factors, and stage at presentation, suggesting different risk patterns across age groups. Most of the cases in this study cohort presented locally advanced disease at the moment of diagnosis, supporting the need for screening and care strategies adapted to age and individual risk in this setting. Future studies incorporating molecular profiling and survival outcomes will be essential to refine risk stratification and inform breast cancer control policies.