<![CDATA[Background: Breast cancer is the most common malignancy among women worldwide, representing a significant public health problem due to its high incidence and mortality rates. Among various prognostic factors, age has been inconsistently reported in the literature, despite its potential biological implications. This study aims to clarify the prognostic relevance of age in breast cancer by analyzing its association with survival outcomes and tumor biomarker expressions, particularly Human Epidermal Growth Factor Receptor 2 (HER2) and Ki-67.Methods: A retrospective cohort study was conducted on breast cancer patients treated at public hospitals and Private Hospitals in Surakarta, Indonesia, diagnosed between 2013 and 2015. Data were gathered from 70 subjects, selected based on complete biomarker, chemotherapy, and follow-up records. Patient age was categorized into three groups: < 40 years, 40-59 years, and ≥ 60 years. Immunohistochemical methods determined HER2 and Ki-67 expressions. Statistical analyses included Kaplan-Meier survival curves and Chi-square tests. Results: Patients aged 40-59 years exhibited superior survival outcomes (mean survival of 106.77 months) compared to younger (< 40 years) and older subjects (≥ 60 years), whose mean survivals were approximately 52 months. HER2 expression showed no significant age-related variation (p = 0.726), whereas Ki-67 expression did, correlating higher proliferation rates with middle-aged patients (p = 0.020).Conclusions: Age appears to be a clinically relevant factor associated with breast cancer prognosis and tumor proliferative characteristics. Incorporating age-related biological differences into prognostic evaluation may enhance risk stratification and inform more tailored treatment and follow-up strategies for breast cancer patients.]]>
