Oral Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2021

Overall 5-year survival of breast cancer patients - the real life experience from linked data (#81)

Jesmin Shafiq 1 2 3 , Roya Merie 2 4 , Patsy S Soon 5 6 7 , Geoff Delaney 1 2 3 8
  1. Collaboration for Cancer Outcomes Research and Evaluation (CCORE), Liverpool hospital, Liverpool, NSW, Australia
  2. School of Clinical Medicine, Faculty of Medicine and Health, University of New South Wales, Sydney, NSW, Australia
  3. Ingham Institute for Applied Medical Research , Liverpool , NSW, Australia
  4. SWSLHD Cancer Services, Liverpool Hospital, Liverpool, NSW, Australia
  5. Department of Surgery, Bankstown Hospital, Bankstown, NSW, Australia
  6. Medical Oncology Group, Ingham Institute for Applied Medical Research, Liverpool, NSW, Australia
  7. BreastScreen South Western Sydney Local Health District, Liverpool, NSW, Australia
  8. Liverpool and Macarthur Cancer Therapy Centres, Liverpool Hospital, Sydney South West Local Health District, Liverpool, NSW, Australia

Background

Breast cancer remains the second most common cause of death from cancer among females.1 In Australia, real-life population-based information related to evidence-based treatment practices and their influence on 5-year overall survival of breast cancer patients are limited.

Objectives

This study was conducted to determine breast cancer 5-year overall survival and the association between survival and socio-demographic, pathological and treatment factors from cancer registry-based data source.

Methods

Data were obtained from the New South Wales (NSW) and Australian Capital Territory (ACT) Cancer Registries linked with Admitted Patient Data Collection (APCD), Registry of Births, Deaths, and Marriages (RBDM) and public/private radiotherapy departmental data. Women diagnosed with primary breast cancer in NSW and ACT between 01/01/2009-31/12/2014 and followed up to 31 December 2018 were included. Kaplan-Meir survival curve and Cox regression analyses assessed the significant factors influencing survival.

Results

Twenty-nine thousand three hundred and five (N=29,305) patients were included. The 5-year overall survival was 88.1% and median survival time was 78.2 months. Significant factors (p<0.001) associated with worse survival were: older age, local birthplace (versus overseas), lower socio-economic status (SES) and larger and more advanced tumors. Living in remote areas had a survival disadvantage although the effect was not significant (p>0.05). Patients receiving BCS alone had 1.8 times higher risk of death within 5 years compared to those receiving BCS+RT, (Hazard ratio (HR)=1.78, 95% CI 1.57–2.08). In node positive patients post mastectomy, those not receiving RT had 1.2 times higher risk of death (p<0.05) (HR=1.15, 95% CI 1.01-1.31).

Conclusions

Survival is negatively impacted when evidence-based treatment is not followed, as seen in patients not receiving RT post BCS or post mastectomy with high-risk features. Additionally, the observed worse overall survival amongst women in lower SES groups and those living away from cities highlights the need for equitable service delivery across the country.

  1. Breast cancer in Australia statistics | Cancer Australia. Available at: https://www.canceraustralia.gov.au/affected-cancer/cancer-types/breast-cancer/breast-cancer-australia-statistics. Accessed 27 May 2021.