Purpose Through linked registry and tertiary hospital data, we present breast cancer specific survival (BCSS) outcomes from an Australian contemporary patient cohort. Methodology Breast Service patients with primary diagnosis between 2007-22, were linked to the Victoria Cancer Registry and National Death Index. We assessed the association between BCSS and age, stage, and detection method at diagnosis (BreastScreen or other). Results 5,352 patients were identified (median follow-up 4.5 years). 8.0%, 18.4%, 66.0% and 7.5% were aged <40, 40-49, 50-74 and ≥75, respectively. 46.4% were screen-detected, majority aged 50-74 (89.4%). Disease was Stage 0, 1, 2a, 2b, 3 and 4 at diagnosis in 15.7%, 37.9%, 16.0%, 8.7%, 7.6% and 1.9% respectively. 9.5% underwent neoadjuvant therapy. Univariate analyses showed BCSS differed significantly (p<0.0001) by age group, stage and detection method. 5-year BCSS was 91.3% for patients aged <40, 94.7% for 40-49, 96.0% for 50-74 and 84.3% for ≥75. 5-year BCSS was 99.0% Stage 1/2a disease and 89.5% for Stage 2b/3 disease; 10-year BCSS was 96.7% and 83.6% respectively. After adjustment for age, stage and detection, age-related BCSS differences remained only for patients ≥75 vs 50-74 (HR=3.27, p<0.001), with ongoing worse BCSS for Stage 2b/3 vs Stages 1/2a (HR=4.90, p<0.001), and diagnosis outside BreastScreen (HR=2.19, p<0.001). Conclusion Survival was excellent for early stage and screen-detected breast cancer, but worse in older patients (≥75). For patients aged <75, lower BCSS was driven largely by stage at diagnosis and detection method, rather than age. Adjusted analyses of real-world data can identify patient groups with poorer outcomes.