Results
In our study, the mean age of the patients during diagnosis of breast cancer was 56.16 ±12.71 years, the mean age of the premenopausal patients was 46.84 ±6.44 years (minimal age: 19 years, maximal age: 55 years), and the mean age of the postmenopausal patients was 66.02 ±9.96 years (minimal age: 44 years, maximal age: 96 years). Premenopausal patients between 47-52 years of age and postmenopausal patients were between 58-65 years of age were found to develop a breast cancer peak.
There was no significant difference between the groups in terms of tumour histology (p = 0.795) (Table 1). In 22.55% of the premenopausal patients, the tumour diameter was < 2 cm, in 56.17% the tumour diameter was 2-5 cm, and in 21.28% of the patients the tumour size was greater than 5 cm. In postmenopausal patients these figures were, respectively, 22.8%, 64.77%, and 12.43%. In premenopausal patients, the number of patients with tumor diameter greater than 5 cm was significantly higher than postmenopausal patients (p = 0.047). The axillary lymph node in 76.60% of premenopausal patients and in 57.51% of postmenopausal patients was positive. Lymph node involvement was significantly higher in the premenopausal group (p < 0.001).
We found that patients in the premenopausal group had a higher likelihood of positive expression of OR than patients in the postmenopausal group (55.8% vs. 44.2%, p = 0.002). For patients in the premenopausal group PR was more likely to show positive expression than for those in the postmenopausal group (52.7% vs. 40.9%, p = 0.014). It was also found that the probability of OR and PR showing double positive expression in the premenopausal group (Table 2) was higher than in the postmenopausal group (53.61% vs. 30.05%, p < 0.0001). OR+ and PR– were significantly higher in the postmenopausal group than in the premenopausal group (15.32% vs. 24.87% p = 0.013). Similarly, OR– and PR+ were significantly higher in the postmenopausal group than in the premenopausal group (4.25% vs. 12.95%, p = 0.001). OR– and PR– were found to be significantly higher in the postmenopausal group than in the premenopausal group (28.08% vs. 43%, p < 0.001). HER2 positivity was significantly higher in the postmenopausal group than in the group premenopausal (11.91% vs. 19.17% p = 0.038). Ki67 expression was significantly higher in the premenopausal group than in the postmenopausal group (33.19% vs. 22.8%, p = 0.017).
Chemotherapy, radiotherapy, and endocrine therapy for the premenopausal disease were more frequently performed (Table 3). Chemotherapy treatment was found to be higher in the premenopausal group than in the postmenopausal group (83.83% vs. 73.06%, p = 0.007). Radiotherapy was used more frequently in the premenopausal group than in the postmenopausal group (22.55% vs. 13.47%, p = 0.008). Endocrine therapy was used more frequently in the premenopausal group than in the postmenopausal group (30.21% vs. 20.73%, p < 0.025). There was no significant difference in anti-HER2 treatment (8.09% vs. 4.66%, p = 0.149). Breast-conserving surgery was performed more frequently in the premenopausal group (9.36% vs. 3.11%, p = 0.004). While 90% of premenopausal patients undergoing breast-conserving surgery completed their five-year lifespan, 88% of postmenopausal patients completed their five-year lifespan.
