Factors influencing breast cancer outcomes in Australia: A systematic review

Purpose This systematic review evaluates factors influencing breast cancer outcomes for women treated in Australia, facilitating the exploration of disparities in breast cancer outcomes for certain groups of women in Australia. Method A systematic literature search was performed using MEDLINE and Scopus focusing on breast cancer in Australia with outcome measures being breast cancer survival and recurrence with no restrictions on date. Risk of bias was assessed using Cairns Assessment Scale for Observational studies of Risk factors (CASOR). Results Fifteen quantitative studies were included: two were high quality, 11 were intermediate quality, and two were low quality. Traditional risk factors such as invasive tumour type, larger size, higher grade and stage, lymph node involvement and absence of hormone receptors were found to be associated with breast cancer mortality. Being younger (<40 years old) and older (>70 years old), having more comorbidities, being of lower socioeconomic status, identifying as Aboriginal or Torres Strait Islander, living in more rural areas or having a mastectomy were factors found to be associated with poorer breast cancer outcomes. Conclusion Despite the heterogeneity of the studies, this review identified significant risk factors for breast cancer mortality and recurrence. The use of this data would be most useful in developing evidence-based interventions and in optimising patient care through creation of a prediction model. PROSPERO registration CRD42017072857.