Investigation of prognostic factors in hormone-positive HER2-negative metastatic breast cancer patients

INTRODUCTION: 2.3 million patients are newly diagnosed with cancer worldwide each year. Breast cancer is the most common type of cancer in women. The aim of our study is to examine the relationship between OS and age at diagnosis, menopausal status, smoking, alcohol use, comorbidities such as hypertension and diabetes, tumor size, Ki-67 index, ECOG performance status, BMI, metastasis status, and whether or not patients have received major therapies such as CDK 4/6 inhibitors and the taxane anthracycline capecitabine. This study aims to highlight the contribution of patient-related factors, in addition to treatment, to prognosis in patients with metastatic breast cancer. MATERIALS AND METHODS: This retrospective study evaluated 119 patients diagnosed with metastatic HR-positive/HER2-negative breast cancer at Manisa Celal Bayar University Faculty of Medicine between 2015 and 2023. Clinicopathological data and survival outcomes were analyzed. Data obtained in the study were analyzed using the SPSS Statistics 29.0 software package. Cox regression analysis was performed to identify prognostic factors affecting the risk of death. Univariate Cox regression analyses were performed, and variables with p<0.250 were included in the multivariate model. Multivariate Cox regression results are presented as Hazard Ratio (HR), 95% Confidence Interval (CI), and p-value. In all statistical tests, p<0.05 was considered significant. RESULTS: Tumor size (HR=1.382, 95% CI=1.167–1.637, p<0.001), presence of hypertension (HR=5.960, 95% CI=2.291–15.509, p<0.001), treatment regimen (overall p=0.046), and menopausal status (postmenopause; HR=4.236, 95% CI=1.238–14.492, p=0.021) were significantly associated with survival. In treatment subgroups, the risk of death was significantly reduced in those receiving ribociclib (HR=0.284, 95% CI=0.097–0.832, p=0.022). Similarly, a survival advantage was found in those receiving palbociclib treatment (HR=0.433, 95% CI=0.189–0.992, p=0.048). CONCLUSION: In our study, tumor size, menopausal status, and hypertension were found to be prognostic factors. The use of CDK 4/6 inhibitors, and particularly ribociclib among CDK 4/6 inhibitors, was confirmed to provide a survival advantage in HR-positive, HER2-negative metastatic breast cancer patients. KEYWORDS: advanced breast cancer, prognostic factors, survival.