This study focused on the characteristics of postmenopausal breast cancer in the population of southeastern Europe. This retrospective study explored the clinical, epidemiological, and molecular characteristics of women with postmenopausal breast cancer. Material and methods: A retrospective cohort study was performed on 721 postmenopausal breast cancer patients selected from the database of our institution. The data collected consisted of age, living environment, location of the breast tumor, stage of the disease, and molecular sub-type. Patient characteristics were collected based on a systematic chart audit from medical records. The data were analyzed using SPSS 20.0 and Pearson analysis. Results: The most frequent age range for breast cancer diagnosis was 51 to 70 years old. Most of the patients (80.7%) came from an urban environment. The vast majority of patients were initially diagnosed in stage II (40.3%) and III (30.3%). The most frequent molecular sub-types were luminal B (39%) and luminal A (35.4%). Almost half of the breast tumors were located in the upper outer quadrant (48.8%). Conclusions: The results of this study describe the profile of patients in southeastern Europe within our institution diagnosed with postmenopausal breast cancer. In our study, patients were first diagnosed with more advanced stages of breast cancer compared with other European countries.

With improved survival, more patients with prior breast cancer are at risk of having a second primary cancer diagnosed. The pattern and impact of second primary cancers following breast cancer is important for overall breast cancer therapeutic management. Our study is a first analysis of the trend of second primary tumours over time in terms of incidence, sites with significantly elevated risks and correlation with stage, molecular subtype and therapeutic strategies conducted in Eastern Europe in postmenopausal women with breast cancer. Patients and methods: Our study population included 28 patients with prior breast cancer (BC) and second primary tumours, which were diagnosed and treated in our Institution between 2004 and 2017. The criteria for selection were based on the completeness of the documentation of the first treatment for breast cancer, stage of disease, molecular subtype, the site of origin of the second tumours and the survival data. Results: An increased risk of second primary cancer was associated with the 51–60 years age group (53.6%), with the greater prevalence in patients living in urban environments (82.1%). The use of chemotherapy increased the risk of the occurrence of gynecological second malignancies (75%). Our study is a first analysis of the trend of second primary tumours over time in terms of identifying sites with significantly elevated risks and correlation with therapeutic strategies conducted in Eastern Europe in postmenopausal women with breast cancer. Conclusions: Our study is a first analysis of the trend of second primary tumours over time in terms of correlation with luminal subtype and stage at diagnosis of primary cancer sites with significantly elevated risks and correlation with therapeutic strategies in postmenopausal women with breast cancer conducted in Eastern Europe. The reported time from primary to second primary malignancy onset, with a significantly higher rate for postmenopausal breast cancer patients, was less than one year (50%). With the advances and wider availability of genetic testing (e.g., gene panels), patients diagnosed with multiple primaries should be increasingly investigated for an underlying cancer predisposition. Postmenopausal women with breast cancer may benefit from increased surveillance and advice to avoid second malignancies.