Increasing rates of surgical treatment and preventing comorbidities may increase breast cancer survival for Aboriginal women

Abstract

BackgroundLower breast cancer survival has been reported for Australian Aboriginal women compared to non-Aboriginal women, however the reasons for this disparity have not been fully explored. We compared the surgical treatment and survival of Aboriginal and non-Aboriginal women diagnosed with breast cancer in New South Wales (NSW), Australia.MethodsWe analysed NSW cancer registry records of breast cancers diagnosed in 2001–2007, linked to hospital inpatient episodes and deaths. We used unconditional logistic regression to compare the odds of Aboriginal and non-Aboriginal women receiving surgical treatment. Breast cancer-specific survival was examined using cumulative mortality curves and Cox proportional hazards regression models.ResultsOf the 27 850 eligible women, 288 (1.03%) identified as Aboriginal. The Aboriginal women were younger and more likely to have advanced spread of disease when diagnosed than non-Aboriginal women. Aboriginal women were less likely than non-Aboriginal women to receive surgical treatment (odds ratio 0.59, 95% confidence interval (CI) 0.42-0.86). The five-year crude breast cancer-specific mortality was 6.1% higher for Aboriginal women (17.7%, 95% CI 12.9-23.2) compared with non-Aboriginal women (11.6%, 95% CI 11.2-12.0). After accounting for differences in age at diagnosis, year of diagnosis, spread of disease and surgical treatment received the risk of death from breast cancer was 39% higher in Aboriginal women (HR 1.39, 95% CI 1.01-1.86). Finally after also accounting for differences in comorbidities, socioeconomic disadvantage and place of residence the hazard ratio was reduced to 1.30 (95% CI 0.94-1.75).ConclusionPreventing comorbidities and increasing rates of surgical treatment may increase breast cancer survival for NSW Aboriginal women.

Variations in outcomes for Indigenous women with breast cancer in Australia: A systematic review

“…two high-quality studies published after 2010 showed a consistent pattern of variations in clinical management, both nationally for 5.4 million women (1% Indigenous; Roder et al, 2012) and at a state-level (n = 27,833, 1% Indigenous; Supramaniam et al, 2014). In particular, Indigenous women were 40% less likely to receive any surgery (Supramaniam et al, 2014), and where surgical management was undertaken, they were more likely to undergo mastectomy rather than complete local excision compared to non-Indigenous women (Roder et al, 2012;Supramaniam et al, 2014).…”

“…12 months of diagnosis after adjustment for a range of key demographic and clinical factors (Supramaniam et al, 2014). 12 months of diagnosis after adjustment for a range of key demographic and clinical factors (Supramaniam et al, 2014).…”

“…Condon et al, 2005bCondon et al, , 2014Dasgupta et al, 2012;Morrell et al, 2012;Roder et al, 2012;Spilsbury et al, 2005;Supramaniam et al, 2014).All of the seven high-quality studies(Condon et al, 2005bDasgupta et al, 2012;Morrell et al, 2012;Roder et al, 2012;Spilsbury et al, 2005;Supramaniam et al, 2014) that also reported survival estimates after adjustment for survival determinants including socio-demographics, spread of disease, comorbidities or treatmentrelated factors found poorer adjusted survival among Indigenous women, although only five reached statistical significance(Condon et al, 2005bDasgupta et al, 2012;Morrell et al, 2012;Roder et al, 2012).The adjusted estimates differed by the combination of covariates considered during statistical analysis. None of the four papers that reported significant survival differentials after adjusting for a measure of stage at diagnosis considered comorbidities or treatment-related factors(Condon et al, 2005b;Dasgupta et al, 2012;Morrell et al, 2012;Roder et al, 2012).…”

The Impact of Rurality and Disadvantage on the Diagnostic Interval for Breast Cancer in a Large Population-Based Study of 3202 Women in Queensland, Australia

“…Other studies have reported ethnic disparities associated with diagnostic delay [71,72]. In Australia, Indigenous women have lower rates of breast screening [13], more extensive disease at diagnosis [73], and less optimal clinical management [74]. While we are unable to assess the exact reasons for the longer diagnostic interval for Indigenous women in our study, it is possible that the differences are caused by issues with accessibility and potentially a lack of culturally sensitive and appropriate health care.…”

Cancer Data and Aboriginal Disparities (CanDAD)—developing an Advanced Cancer Data System for Aboriginal people in South Australia: a mixed methods research protocol

“…9 13–17 These linkage studies have demonstrated the value of assessing cancer outcomes in relation to patient treatment, comorbidity and various sociodemographic features. Work in New South Wales has compared survival and surgical treatment of Aboriginal and other Australians with breast, colorectal, non-small cell lung and prostate cancers by linking their cancer registry records with hospital admission and death records 13…”