High comorbidity and tumor proliferation predict survival of localized breast cancer patients after curative surgery : a retrospective analysis of real-world data in Finland

Abstract

Breast cancer is the most common cancer among women worldwide. Although the prognosis of breast cancer has improved over the years, clinical trials are often composed of selected patient groups that may not represent patients treated in clinical practice. Real-world studies are needed to gain an understanding of the characteristics and treatment outcomes of unselected patient populations. The aim of this study was to analyze the characteristics of breast cancer patients treated at Turku University Hospital (Tyks) and identify prognostic factors for survival.

This retrospective study was conducted by collecting data on all patients newly diagnosed with breast cancer at Tyks in 2019 and analyzing the impact of patient and tumor characteristics on real-world treatment outcomes.

In 2019, a total of 458 new breast cancer cases were diagnosed at Tyks, of which 95% (n = 435) were localized and 5% (n = 23) were metastatic. In localized breast cancer, five-year overall survival (OS) was 90.9%, and five-year disease-free survival (DFS) was 93.5%.

High tumor proliferation, low estrogen receptor expression and large tumor size were predictors of decreased survival in localized breast cancer. High comorbidity and poor performance status were associated with worse prognosis in the localized cohort. Patients who received postoperative radiotherapy experienced improved survival outcomes.

Thorough clinical evaluation of patient performance status and comorbidities, as well as well-established tumor characteristics, reliably predict real-world survival in a population where five-year OS in breast cancer is over 90 %. These findings highlight the quality of pathological analyses performed at Tyks and serve as a reminder that carefully evaluated tumor biomarkers remain essential for clinical decision-making, even as we enter an era of novel prognostic tools in oncology. Furthermore, the results support the crucial role of postoperative adjuvant radiotherapy in improving patient survival.