Breast cancer demographics, screening and survival outcome at a regional Australian cancer centre: a retrospective study

Abstract

Background: Breast cancer is the third most commonly diagnosed cancer in Australia and the fourth most common cause of death from cancer. This study aimed to describe patient demographics and estimate survival for patients treated at a regional Australian cancer centre. Methods: A retrospective cohort study was conducted of breast cancer patients who had been treated at North West Cancer Centre from the period of 2008 to 2015. Demographic variables were summarised and estimates of Kaplan-Meier survival for the cohort and breast cancer subtypes were generated. Cox models were used to investigate time to breast cancer-related death for cancer stage, grade, age and distance from the treatment centre. Hazards of death associated with time from diagnosis until treatment and surgery were also assessed. Results: The cohort comprised of 285 patients that were treated at North West Cancer Centre. Mean and median age was 60 years (range 35-95); three were males. One hundred and twenty-six (44%) patients had screen-detected breast cancer. One hundred and fifty-two (53%) patients had breast conservative surgeries and 117 (41%) underwent mastectomies. Intrinsic histology subtypes Luminal A, Luminal B HER2 positive, Luminal B HER2 negative, HER2 over-expression and triple negative (basal-like) were 75 (29%), 37 (14%), 98 (37%), 12 (4.6%) and 41 (16%) respectively. One hundred and fifty-six (55%) patients received adjuvant chemotherapy, 189 (66%) patients has been on adjuvant endocrine therapy and 149 (52%) patients had adjuvant radiotherapy. Five-year observed survival was 86.9% (95% CI 80.7 - 91.3). Adjusted analyses indicated that increasing stage and age were significantly associated with greater hazard of death (P < 0.001). There was insufficient evidence to suggest increasing time from diagnosis until surgery and treatment were associated with hazard of death. Conclusions: Survival outcome of breast cancer at our regional centre is relatively comparable to Australia wide breast cancer survival. Increasing age and breast cancer stage were associated with a greater hazard of death in adjusted analyses.