Age-Related Disparity in Immediate Prognosis of Patients with Triple-Negative Breast Cancer: A Population-Based Study from SEER Cancer Registries

Background Triple-negative breast cancer (TNBC) has been demonstrated to carry poor prognosis, but whether or not there exists any age-related variation in TNBC outcomes has yet to be elucidated. The current population-based study investigated the early survival pattern of elderly women with TNBC and identified outcome-correlated factors. Patients and Methods We searched the Surveillance, Epidemiology, and End Results (SEER) database and enrolled female primary non-metastatic TNBC cases. The patients were subdivided into elderly (>= 70 years) and young groups (<70 years). The survival status of elderly patients was compared to that of the younger women. The primary and secondary endpoints were cancer-specific survival (CSS) and overall survival (OS) respectively. Results 9908 female TNBC patients diagnosed from 2010 to 2011 were included in the current study (20.4% elderly). Elderly patients with relatively advanced diseases exhibited distinctly worse cancer-specific (log-rank, p<0.001) and overall survival (log-rank, p<0.001) than their young counterparts. Advanced age at diagnosis (>= 70 years) was significantly predictive of poor outcome in terms of CSS (hazard ratio (HR), 2.125; 95% confidence interval (CI), 1.664 to 2.713; p<0.001) and OS (HR, 3.042; 95% CI, 2.474 to 3.740; p<0.001). Underuse of curative treatment especially radiotherapy was more prevalent in elderly women with stage II or III diseases than in younger patients. Conclusion Elderly patients with TNBC displayed elevated early mortality within the first two years of diagnosis compared to the younger individuals. The observed lower rate of loco-regional treatment might be associated with worse cancer-specific outcome for these patients.