Breast cancer treatment and survival differences in women in remote and socioeconomically disadvantaged areas, as demonstrated by linked data from New South Wales (NSW), Australia

Abstract

Introduction Reducing variations in cancer treatment and survival is a key aim of the NSW Cancer Plan. Variations in breast cancer treatment and survival in NSW by remoteness and socioeconomic status of residence were investigated to determine benchmarks. Reducing variations in cancer treatment and survival is a key aim of the NSW Cancer Plan. Variations in breast cancer treatment and survival in NSW by remoteness and socioeconomic status of residence were investigated to determine benchmarks. Methods A retrospective cohort study used linked data for invasive breast cancers, diagnosed in May 2002 to December 2015 from the NSW Cancer Registry, with corresponding inpatient, and medical and pharmaceutical insurance data. Associations between treatment modalities, area socioeconomic status and residential remoteness were explored using logistic regression. Predictors of breast cancer survival were investigated using Kaplan–Meier product-limit estimates and multivariate competing risk regression. Results Results indicated a high 5-year disease-specific survival in NSW of 90%. Crude survival was equivalent by residential remoteness and marginally lower in lower socioeconomic areas. Competing risk regression showed equivalent outcomes by area socioeconomic status, except for the least disadvantaged quintile, which showed a higher survival. Higher sub-hazard ratios for death occurred for women with breast cancer aged 70 + years, and more advanced stage. Adjusted analyses indicated more advanced stage in lower socioeconomic areas, with less breast reconstruction and radiotherapy, and marginally less hormone therapy for women from these areas. Conversely, among these women who had breast conserving surgery, there was higher use of chemotherapy. Remoteness of residence was associated in adjusted analyses with less radiotherapy and less immediate breast reconstruction. In these short term data, remoteness of residence was not associated with lower survival. Conclusion This study provides benchmarks for monitoring future variations in treatment and survival.

The contribution of prognostic factors to socio‐demographic inequalities in breast cancer survival in Victoria, Australia

“…Some Australian studies of female breast cancer survival have reported no strong disparities in breast cancer survival between inner‐regional areas and urban areas 9,24,26,32 albeit in different Australian states. Yu et al 34 reported that for the most recent period covered in their study (2002–2005), after adjusting for SES (as well as age and stage of diagnosis), the estimated relative excess risk of breast cancer death for women living in inner‐regional areas compared with major city dwellers was 0.90, but this survival advantage was not statistically significant, albeit after adjusting for cancer stage.…”

“…There have been several Australian studies that have examined socio‐economic and rural–urban disparities in breast cancer mortality 29,30 . Some have examined socio‐economic disparities alone 7,31 rural–urban disparities alone 24,26 or both 8,9,32–34 . In most Australian studies that included a measure of cancer stage at initial diagnosis, the effect of stage on survival was either statistically controlled when estimating socio‐economic and rural–urban disparities 7–9,32,34 or it was used to stratify the sample, and then disparities were examined within stage 26 .…”

Breast cancer care and surgery in Australia and New Zealand: compliance of the BreastSurgANZ quality audit with international standards

“…We note that the stratification of hospitals as high and low volume using the EUSOMA definition of 150 patients per year is not validated for the ANZ population, where a significant proportion of the population live in regional or geographically remote regions. In Australia, geographic remoteness is associated with higher rates of mastectomy, 23 reduced used of radiotherapy and less immediate breast reconstruction, but not lower survival 24 . In ANZ, a ‘low‐volume’ regional surgeon may participate in a ‘high‐volume’ metropolitan MDT and refer patients to metropolitan services.…”

“…and high-volume centre (HVH ≥150 patients p.a.). As per EUSOMA definition 90.9% (239) of centres were considered low-volume centres and 9.1% (24) were high-volume centres.…”

“…In Australia, geographic remoteness is associated with higher rates of mastectomy, 23 reduced used of radiotherapy and less immediate breast reconstruction, but not lower survival. 24 In ANZ, a 'low-volume' regional surgeon may participate in a 'high-volume' metropolitan MDT and refer patients to metropolitan services. Internal audit has shown that ANZ surgeons meet the ANZ quality threshold for BQA QI-7 and QI-9 (Table 1) if they manage at least 50 patients per year.…”