A cohort study of ethnic differences in use of adjuvant chemotherapy and radiation therapy for breast cancer in New Zealand

Abstract

BackgroundEthnic and socioeconomic inequities in use of breast cancer adjuvant therapy are well documented in many countries including the USA, and are known to contribute to lower breast cancer survival among minority ethnic and socioeconomically deprived women. We investigated ethnic and socioeconomic inequities in use of adjuvant radiotherapy and chemotherapy in a cohort of women with invasive breast cancer in New Zealand.MethodsAll women with newly diagnosed invasive breast cancer during 1999-2012 were identified from the Waikato Breast Cancer Register. Rates of chemotherapy use and radiotherapy use were assessed in women who were deemed to be eligible for chemotherapy (n = 1212) and radiotherapy (n = 1708) based on guidelines. Factors associated with use of chemotherapy and radiation therapy were analysed in univariate and multivariate regression models, adjusting for covariates.ResultsOverall, rates of chemotherapy and radiotherapy use were 69% (n = 836) and 87.3% (n = 1491), respectively. In the multivariate model, significantly lower rates of radiotherapy use were associated with Māori compared with NZ European (Odds Ratio [OR] = 0.63, 0.40-0.98), presence of comorbidity (OR = 0.49, 0.34-0.72), distance from hospital of over 100km (OR = 0.47, 0.23-0.96), mastectomy compared with breast conserving surgery (OR = 0.32, 0.17-0.56) and non-screen compared with screen detection (OR = 0.53, 0.35-0.79). No significant associations were observed between chemotherapy use and ethnic or socio-demographic factors.ConclusionsImproving access for radiotherapy, especially for women who are at a higher risk of not receiving optimum cancer therapy due to ethnicity, geography or socioeconomic status need to be recognized as a priority to reduce inequities in breast cancer care in New Zealand.

Spatial distribution of breast cancer mortality: Socioeconomic disparities and access to treatment in the state of Parana, Brazil

“…Thus, increasing availability and improving access to adjuvant breast CA therapy for women who are at higher risk of not receiving such treatment because of ethnicity, geography or socioeconomic status should be prioritized, which may help minimize the inequalities of breast CA [ 50 ].…”

Driving quality improvement through better data: The story of New Zealand's radiation oncology collection

“…[2][3][4][5] However, access to radiation therapy for cancer treatment may vary due to factors including age, ethnicity, comorbidity, geography/rurality, hospital volume, waiting times and referral pathways. [6][7][8][9] Robust and complete radiation therapy data is needed to assess this variation across geographic, demographic and institutional divides. In Aotearoa/New Zealand, variation in radiation therapy treatment depending on where providers were located relative to where patients lived was noted in 2014, but the data at this time were not considered accurate enough to explore or confirm these variations.…”

“…Globally it is estimated that around half of patients with cancer would benefit from radiation therapy, either as a curative treatment or as palliation 2–5 . However, access to radiation therapy for cancer treatment may vary due to factors including age, ethnicity, comorbidity, geography/rurality, hospital volume, waiting times and referral pathways 6–9 …”