AYKUT TURHAN, NESLİHAN ÖZYURT
Journal of Health Sciences and Medicine - 2025;8(4):709-715
Aims: To evaluate the relationship between age at diagnosis and molecular subtypes of breast cancer in a retrospective single-center cohort at the Ordu University Training and Research Hospital. Methods: We reviewed the data of 139 female patients diagnosed with invasive breast carcinoma between January 2020 and March 2025. Clinical and pathological data, including age at diagnosis, body-mass index (BMI), TNM stage, histological subtype and grade, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) status, and Ki-67 index, were extracted from the medical records. Tumors were classified into luminal A, luminal B, HER2-enriched, and triple-negative subtypes. Patients were stratified into three age groups: <40, 40-59, and ≥60 years. Statistical analyses included chi-square tests for categorical variables, one-way ANOVA for continuous variables, and multivariable logistic regression; p<0.05 was considered significant. Results: The mean age at diagnosis was 56.6±12.5 years (range, 29-83 years); 10.8% were <40 years, 47.5% were 40-59 years, and 41.7% were ≥60 years. The luminal A (41.0%) and luminal B (36.7%) subtypes predominated in the cohort. HER2-enriched (8.6%) and triple-negative (13.7%) tumors were most prevalent in the <40 group, accounting for 6.7% and 46.7% of that cohort, respectively. The variation in molecular subtypes was notably different across the various age groups (X2=22.2, p=0.001). Additionally, the median BMI showed significant differences among the subtypes, with the luminal A group having the highest median BMI of 29.4 kg/m2, while the triple-negative group had the lowest BMI of 26.6 kg/m2 (ANOVA, p=0.012). Furthermore, aggressive subtypes, such as HER2-enriched and triple-negative, were strongly linked to advanced-stage disease (X2=19.4, p<0.001). According to the multivariate analysis, a higher tumor grade was independently associated with non-luminal subtypes (odds ratio=13.96; 95% confidence interval: 4.46-43.69; p<0.001), whereas factors such as age, BMI, and TNM stage did not show a significant association with subtype classification. Conclusion: Age at diagnosis was significantly associated with molecular subtype distribution, BMI, and stage at presentation. Younger patients more frequently exhibit aggressive subtypes, highlighting the need for age-specific screening strategies and personalized treatment.
