LAUSR

Background and Aims: This study aimed to investigate the importance of immunohistochemical (IHC) markers and other prognostic variables in the definition of breast cancer. Patients and Methods: Two hundred female patients who underwent breast cancer surgery were classified into two groups according to age: young women (≤45 years; n = 104) and older women (≥65 years; n = 96). Molecular subtypes and local stages were determined. The Kaplan–Meier method was used to estimate the survival curves. The relationships among categorical variables were analyzed using the Chi-square test. Results: The difference between the tumor diameter and distribution of Ki-67 levels was significant (P = 0.001, P < 0.05). T stage, local stage, histological grade, estrogen receptor status, lymphovascular invasion status, axillary nodal state, human epidermal growth factor receptor 2 status, and distribution of molecular subtypes were correlated (P < 0.05). The mean disease-free survival rates (DFS) at 1, 2, and 5 years were found 92.9%, 86.5%, and 70.1%, respectively, in the young female group. The DFS rates of older patients were 96.7%, 95.4%, and 84.6%, respectively. Conclusion: This study showed that young age was associated with poor prognostic features at the IHC marker level.