Akademik Veri Yönetim Sistemi
ANNALS OF ONCOLOGY, cilt.36, sa.406, ss.370-371, 2025 (SCI-Expanded, Scopus)
Background: Breast cancer is increasingly detected at an early stage after national screening programs. However, adjuvant therapies such as chemotherapy and radiotherapy may elevate the risk of developing secondary malignancies in long-term survivors. Methods: In this retrospective multicenter cohort study, data were collected from 7,552 women diagnosed with primary breast cancer across 15 Turkish Oncology Group centers. Patients who were diagnosed with a second primary malignancy at least one year after their initial breast cancer diagnosis were included in the analysis in order to eliminate cases of synchronous cancers. Second cancer risk was quantified for all cancer sites with ≥10 observed cases―excluding ipsilateral breast tumors―by calculating standardized incidence ratios (SIRs) against age- and sexmatched population rates. Results: In this cohort; 174 patients who developed a second primary malignancy during the ten-year follow-up, the overall incidence was 66% higher than expected (SIR 1.66; 95% CI 1.62—1.79). The greatest excess risk occurred in women diagnosed under age 40 (SIR 7.55; 95% CI 3.62—13.90). By tumor type, sarcoma exhibited the highest relative increase (SIR 5.27; 95% CI 2.81—9.01). Elevated incidence was also observed for colorectal, ovarian, endometrial, lung, and thyroid cancers (all SIRs >1.0). Notably, thyroid malignancies tended to arise earlier during follow-up month , whereas sarcomas appeared later. The standardized incidence ratio (SIR) was found to be higher among patients who received radiotherapy compared to those who did not (1.72 vs. 1.56), and also higher in estrogen receptor-positive patients compared to estrogen receptor-negative ones (2.02 vs. 1.66). Although patients who developed secondary lung cancer demonstrated a trend toward shorter overall survival, this f inding did not reach statistical significance. Conclusions: Extended survival in breast cancer patients is accompanied by an increased predisposition to diverse secondary neoplasms. These findings underscore the necessity for prolonged surveillance strategies in breast cancer survivors, with particular vigilance for radiation-associated and other high-risk second primary tumors.