Age has a U-shaped Relationship with Breast Cancer Outcomes in Women

Abstract Background and Objectives There is insufficient information available on how breast cancer prognosis is affected by age at diagnosis. Our study aimed to examine the association between age at diagnosis and overall survival (OS), breast cancer-specific survival (BCSS) and disease-free survival (DFS) rates. Methods 1054 breast cancer patients were obtained in our retrospective cohort study from March 7, 2013 to December 31, 2019. Patients were dividedinto four groups based on their age. Different age groups were described using the Kaplan-Meier method for OS, BCSS and DFS survival rates. A model of Cox proportional hazards ratio (HR) with restricted cubic splines (RCS) and smooth curve fitting were usedto estimate 95% confidence interval (CI) and hazard ratios (HRs) of OS, BCSS and DFS rates. Results 71 patients (6.74%) died and 144 patients (13.66%) recurred during a median follow-up of 4.86 years. Quarter 2 showed the best OS, BCSS, and DFS rates in the Kaplan-Meier survival analysis. The outcomes of RCS analysis indicated that there was a U-shaped relationship between the age and OS, BCSS and DFS rates despite after adjustment for other confounding factors, the inflection points of OS, BCSS and DFS rates were 44years, 37years and 41years. Conclusions In Asian women, there is a U-shaped association between age at diagnosis and breast cancer outcomes.