Social and emotional wellbeing of Aboriginal and Torres Strait Islander peoples in Aboriginal controlled social housing.

BACKGROUND: Little is known about the wellbeing and aspirations of Aboriginal and Torres Strait Islander peoples living in social housing. Aboriginal and Torres Strait Islander peoples living in social housing face common social housing challenges of low income, higher incidence of mental health issues and poorer health along with specific challenges due to the impacts of colonisation and its ongoing manifestations in racism and inequity. A greater understanding of social and emotional wellbeing needs and aspirations is essential in informing the provision of appropriate support. METHODS: Surveys of social and emotional wellbeing (SEWB) were completed by 95 Aboriginal people aged 16 years and older living in Aboriginal Housing Victoria social housing in 2021. The survey addressed a range of domains reflecting social and emotional wellbeing, as defined by Aboriginal and Torres Strait Islander peoples. RESULTS: Most respondents demonstrated a strong sense of identity and connection to family however 26% reported having 6 or more health conditions. Ill health and disability were reported to be employment barriers for almost a third of people (32%). Improving health and wellbeing (78%) was the most cited aspiration. Experiences of racism and ill health influenced engagement with organisations and correspondingly education and employment. CONCLUSION: Strong connections to identity, family and culture in Aboriginal peoples living in social housing coexist along with disrupted connections to mind, body and community. Culturally safe and appropriate pathways to community services and facilities can enhance these connections. Research aimed at evaluating the impact of strengths-based interventions that focus on existing strong connections will be important in understanding whether this approach is effective in improving SEWB in this population. TRIAL REGISTRATION: This trial was retrospectively registered with the ISRCTN Register on the 12/7/21 with the study ID:ISRCTN33665735.

Evaluation of an Aboriginal and Torres Strait Islander strengths based coaching program: a study protocol.

BACKGROUND: Increasingly, strength-based approaches to health and wellbeing interventions with Aboriginal and Torres Strait Islander Australians are being explored. This is a welcome counter to deficit-based initiatives which can represent a non-Indigenous view of outcomes of interest. However, the evidence base is not well developed. This paper presents the protocol for evaluating a strengths-based initiative which provides life coaching services to Aboriginal and Torres Strait Islander community housing tenants. The study aims to evaluate the effect of life coaching on social and emotional wellbeing (SEWB) of tenants in three Victorian regions. METHODS: The More Than a Landlord (MTAL) study is a prospective cohort study of Aboriginal Housing Victoria tenants aged 16 years and over that embeds the evaluation of a life coaching program. All tenant holders in one metropolitan and two regional areas of Victoria are invited to participate in a survey of SEWB, containing items consistent with key categories of SEWB as understood and defined by Aboriginal and Torres Strait Islander peoples, and key demographics, administered by Aboriginal and Torres Strait Islander peer researchers at baseline, 6 and 18 months. Survey participants are then invited to participate in strengths based life coaching, using the GROW model, for a duration of up to 18 months. Indigenous life coaches provide tenants with structured support in identifying and making progress towards their goals and aspirations, rather than needs. The study aims to recruit a minimum of 200 survey participants of which it is anticipated that approximately 73% will agree to life coaching. DISCUSSION: The MTAL study is a response to Aboriginal and Torres Strait Islander community and organisational requests to build the evidence base for an initiative originally developed and piloted within an Aboriginal controlled organisation. The study design aligns with key principles for research in Indigenous communities in promoting control, decision making and capacity building. The MTAL study will provide essential evidence to evaluate the effectiveness of strengths-based initiatives in promoting SEWB in these communities and provide new evidence about the relationship between strengths, resilience, self-determination and wellbeing outcomes. TRIAL REGISTRATION: This trial was retrospectively registered with the ISRCTN Register on the 12/7/21 with the study ID: ISRCTN33665735 .

Chronic kidney disease and socio-economic status: a cross sectional study.

Objective: This cross-sectional study investigated the relationship between individual-level markers of disadvantage, renal function and cardio-metabolic risk within an Indigenous population characterised by a heavy burden of chronic kidney disease and disadvantage.Design: Using data from 20 Indigenous communities across Australia, an aggregate socio-economic status (SES) score was created from individual-level socio-economic variables reported by participants. Logistic regression was used to assess the association of individual-level socio-economic variables and the SES score with kidney function (an estimated glomerular function rate (eGFR) cut-point of <60 ml/min/1.73 m2) as well as clinical indicators of cardio-metabolic risk.Results: The combination of lower education and unemployment was associated with poorer kidney function and higher cardio-metabolic risk factors. Regression models adjusted for age and gender showed that an eGFR < 60 ml/min/1.73 m2 was associated with a low socio-economic score (lowest vs. highest 3.24 [95% CI 1.43-6.97]), remote living (remote vs. highly to moderately accessible 3.24 [95% CI 1.28-8.23]), renting (renting vs. owning/being purchased 5.76[95% CI 1.91-17.33]), unemployment (unemployed vs employed 2.85 [95% CI 1.31-6.19]) and receiving welfare (welfare vs. salary 2.49 [95% CI 1.42-4.37]). A higher aggregate socio-economic score was inversely associated with an eGFR < 60 ml/min/1.73 m2 (0.75 [95% CI 063-0.89]).Conclusion: This study extends upon our understanding of associations between area-level markers of disadvantage and burden of end stage kidney disease amongst Indigenous populations to a detailed analysis of a range of well-characterised individual-level factors such as overall low socio-economic status, remote living, renting, unemployment and welfare. With the increasing burden of end-stage kidney disease amongst Indigenous people, the underlying socio-economic conditions and social and cultural determinants of health need to be understood at an individual as well as community-level, to develop, implement, target and sustain interventions.

Health and wellbeing outcomes of programs for Indigenous Australians that include strategies to enable the expression of cultural identities: a systematic review.

Indigenous people have long maintained that strong cultural identities are critical to health and wellbeing. The purpose of this systematic review is to examine whether interventions that entail strategies to enable expression of cultural identities for Australian Indigenous peoples are associated with measurable improvements in health and wellbeing. Peer-reviewed articles that reported quantitatively expressed health and wellbeing outcomes involving Indigenous Australian participants only were included. The cultural intervention component was defined and assessed by Indigenous researchers on the team. A narrative analysis was conducted. The protocol was registered on PROSPERO (CRD42015027387). Thirteen articles describing eleven studies were identified, including one randomised control trial (RCT), one cluster RCT and two studies with non-randomised controls. Other studies reported on case series or cross-sectional studies. All except two studies described multiple intervention strategies. Eight studies showed significant improvement in at least one psychosocial, behavioural or clinical measure, with two showing a positive direction of effect and one showing no improvement. Publication bias may discourage researchers to report negative findings of these interventions. Although studies vary in quality, this review provides evidence that interventions that include opportunities for expression of cultural identities can have beneficial effects for Australian Indigenous peoples.

The impact of health promotion on trachoma knowledge, attitudes and practice (KAP) of staff in three work settings in remote Indigenous communities in the Northern Territory.

BACKGROUND: Globally, trachoma is the leading cause of infectious blindness and Australia is the only developed country with endemic trachoma. It is found in remote Indigenous communities burdened with poverty, overcrowding and poor hygiene. Lack of culturally appropriate health promotion, a small trachoma workforce and lack of awareness and support for trachoma elimination in general, were early barriers. METHODS: A cross-sectional pre-post study using a convenience sample, was conducted in clinics, schools and community work-settings from 63 of the 82 remote Aboriginal communities identified as being at risk of trachoma in the Northern Territory (NT). The study assessed the effect of a multi-component health promotion strategy aimed at increasing knowledge, attitude and practice amongst health, education and community support settings staff. Data were collected between 2010 and 2012. The health promotion initiatives were introduced in communities in staggered delivery over a one-year period; 272 participants were surveyed at baseline and 261 at follow-up. RESULTS: Trachoma related knowledge, attitudes and practice increased across all settings and for all primary outcome measures. Across all settings, there was a significant increase in the proportion of participants reporting the most important thing to do if a child has a 'dirty' face is to 'wash it every time its dirty' (61.6% cf 69.7%; X2p = 0.047), a significant reduction in the proportion of respondents answering 'no' to the question "Is it normal for kids to have dirty faces in your community' (40.5% cf 29.6%; X2p = 0.009) and a significant increase in reported capacity to teach others about trachoma prevention (70.8% cf 83.3%; X2p <0.001). CONCLUSION: Health promotion was associated with increased trachoma knowledge, attitude and practice amongst health, education and community support staff working with children and in remote NT communities. In the early stages of the trachoma health promotion program, this increased trachoma awareness and improved local workforce capacity and support for trachoma elimination in three health promotion settings in remote communities in the NT.

Low rates of predominant breastfeeding in hospital after gestational diabetes, particularly among Indigenous women in Australia.

OBJECTIVES: To investigate rates of 'any' and 'predominant' breastfeeding in hospital among Indigenous and non-Indigenous women with and without gestational diabetes mellitus (GDM). METHODS: A retrospective study of singleton infants born from July 2007 to December 2010 at Cairns Hospital, Australia, following GDM pregnancy, using linked hospital and birth data (n=617 infants), with a subsample of medical record reviews (n=365 infants). Aggregate data were used to compare to breastfeeding rates among infants born following non-GDM pregnancy (n=7,894 infants). RESULTS: More than 90% of all women reported any breastfeeding before hospital discharge. About 80% of women without GDM reported predominant breastfeeding. Despite significant increases over time (p<0.0001), women with GDM were less likely to predominantly breastfeed (OR 0.32, 95%CI 0.27-0.38, p<0.0001); with lower rates among Indigenous women (53%) compared with non-Indigenous (60%) women (OR 0.78, 0.70-0.88, p<0.0001); and women having a caesarean birth or pre-term infant. CONCLUSIONS: Rates of predominant in-hospital breastfeeding were lower among women with GDM, particularly among Indigenous women and women having a caesarean or pre-term birth. IMPLICATIONS: Strategies are needed to support predominant in-hospital breastfeeding among women with GDM.

Clinical outcomes associated with albuminuria in central Australia: a cohort study.

BACKGROUND: Chronic kidney disease (CKD) and end-stage-kidney disease (ESKD) continue to be under-diagnosed and a major burden for Aboriginal communities in central Australia. The aim of this study was to examine the risk of poor clinical outcomes associated with elevated albumin-to-creatinine ratio (ACR) among Aboriginal people in central Australia. METHODS: Cox proportional hazards models were used to estimate the risk of end stage kidney disease (ESKD), dialysis, CVD (cardiovascular disease) and mortality associated with participants' baseline albuminuria reading from a 10-year cohort study of Aboriginal people (n = 623) from three communities in central Australia. Predictors of progression of albuminuria were also examined in the context of the Kidney Health Australia (KHA) Risk Matrix. RESULTS: A baseline ACR level of ≥3.5 mg/mmol was associated with an almost 10-fold increased risk of ESKD (95%CI 2.07-43.8) and a 15-fold risk of dialysis (95%CI 1.89-121). Albuminuria ≥3.5 mg/mmol was also associated with a borderline 63 % increased risk of CVD (95%CI 0.98-2.71). No significant association was observed with mortality from all-causes or chronic disease. Diabetes and a waist-to-hip ratio ≥0.90 independently predicted a two-fold increased risk of a progression to higher ACR levels. CONCLUSIONS: A single measure of moderately increased albuminuria was a strong predictor of renal failure in this population. A single spot urine ACR analysis in conjunction with the KHA Risk Matrix may be a useful and efficient strategy to screen for risk of CKD and progression to dialysis in remote communities. A focus on individuals with diabetes and/or central obesity for strategies to avoid increases in albuminuria may also prevent future CKD and CVD complications.

Progression of Kidney Disease in Indigenous Australians: The eGFR Follow-up Study.

BACKGROUND AND OBJECTIVES: Indigenous Australians experience a heavy burden of CKD. To address this burden, the eGFR Follow-Up Study recruited and followed an Indigenous Australian cohort from regions of Australia with the greatest ESRD burden. We sought to better understand factors contributing to the progression of kidney disease. Specific objectives were to assess rates of progression of eGFR in Indigenous Australians with and without CKD and identify factors associated with a decline in eGFR. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This observational longitudinal study of Indigenous Australian adults was conducted in >20 sites. The baseline cohort was recruited from community and primary care clinic sites across five strata of health, diabetes status, and kidney function. Participants were then invited to follow up at 2-4 years; if unavailable, vital status, progression to RRT, and serum creatinine were obtained from medical records. Primary outcomes were annual eGFR change and combined renal outcome (first of ≥30% eGFR decline with follow-up eGFR<60 ml/min per 1.73 m(2), progression to RRT, or renal death). RESULTS: Participants (n=550) were followed for a median of 3.0 years. Baseline and follow-up eGFR (geometric mean [95% confidence interval], 83.9 (80.7 to 87.3) and 70.1 (65.9 to 74.5) ml/min per 1.73 m(2), respectively. Overall mean annual eGFR change was -3.1 (-3.6 to -2.5) ml/min per 1.73 m(2). Stratified by baseline eGFR (≥90, 60-89, <60 ml/min per 1.73 m(2)), annual eGFR changes were -3.0 (-3.6 to -2.4), -1.9 (-3.3 to -0.5), and -5.0 (-6.5 to -3.6) ml/min per 1.73 m(2). Across baseline eGFR categories, annual eGFR decline was greatest among adults with baseline albumin-to-creatinine ratio (ACR) >265 mg/g (30 mg/mmol). Baseline determinants of the combined renal outcome (experienced by 66 participants) were higher urine ACR, diabetes, lower measured GFR, and higher C-reactive protein. CONCLUSIONS: The observed eGFR decline was three times higher than described in nonindigenous populations. ACR was confirmed as a powerful predictor for eGFR decline across diverse geographic regions.

Nutritional predictors of successful chronic disease prevention for a community cohort in Central Australia.

OBJECTIVE: To investigate biomarkers of nutrition associated with chronic disease absence for an Aboriginal cohort. DESIGN: Screening for nutritional biomarkers was completed at baseline (1995). Evidence of chronic disease (diabetes, CVD, chronic kidney disease or hypertension) was sought from primary health-care clinics, hospitals and death records over 10 years of follow-up. Principal components analysis was used to group baseline nutritional biomarkers and logistic regression modelling used to investigate associations between the principal components and chronic disease absence. SETTING: Three Central Australian Aboriginal communities. SUBJECTS: Aboriginal people (n 444, 286 of whom were without chronic disease at baseline) aged 15-82 years. RESULTS: Principal components analysis grouped twelve nutritional biomarkers into four components: 'lipids'; 'adiposity'; 'dietary quality'; and 'habitus with inverse quality diet'. For the 286 individuals free of chronic disease at baseline, lower adiposity, lower lipids and better dietary quality components were each associated with the absence at follow-up of most chronic diseases examined, with the exception of chronic kidney disease. Low 'adiposity' component was associated with absence of diabetes, hypertension and CVD at follow-up. Low 'lipid' component was associated with absence of hypertension and CVD, and high 'dietary quality' component was associated with absence of CVD at follow-up. CONCLUSIONS: Lowering or maintenance of the factors related to 'adiposity' and 'lipids' to healthy thresholds and increasing access to a healthy diet appear useful targets for chronic disease prevention for Aboriginal people in Central Australia.

Economic rationalisation of health behaviours: the dangers of attempting policy discussions in a vacuum.

When analysing the health behaviours of any group of people, understanding the constraints and possibilities for individual agency as shaped by the broader societal context is critical. In recent decades, our understanding of the ways in which physical and social environments influence health and health behaviours has expanded greatly. The authors of a recent analysis of Australian Aboriginal health data using an economic 'rational choice model,' published in this journal, claim to make a useful contribution to policy discussions relating to Aboriginal health, but neglect context. By doing so, they neglect the very factors that determine the success or failure of policy change. Notwithstanding the technical sophistication of the analyses, by ignoring most relevant determinants of health, the conclusions misrepresent the lives of Aboriginal and Torres Strait Islander people and therefore risk perpetuating harm, rather than improving health.

Reproductive factors and risk of hormone receptor positive and negative breast cancer: a cohort study.

BACKGROUND: The association of reproductive factors with hormone receptor (HR)-negative breast tumors remains uncertain. METHODS: Within the EPIC cohort, Cox proportional hazards models were used to describe the relationships of reproductive factors (menarcheal age, time between menarche and first pregnancy, parity, number of children, age at first and last pregnancies, time since last full-term childbirth, breastfeeding, age at menopause, ever having an abortion and use of oral contraceptives [OC]) with risk of ER-PR- (n = 998) and ER+PR+ (n = 3,567) breast tumors. RESULTS: A later first full-term childbirth was associated with increased risk of ER+PR+ tumors but not with risk of ER-PR- tumors (≥35 vs. ≤19 years HR: 1.47 [95% CI 1.15-1.88] p(trend) < 0.001 for ER+PR+ tumors; ≥35 vs. ≤19 years HR: 0.93 [95% CI 0.53-1.65] p(trend) = 0.96 for ER-PR- tumors; P(het) = 0.03). The risk associations of menarcheal age, and time period between menarche and first full-term childbirth with ER-PR-tumors were in the similar direction with risk of ER+PR+ tumors (p(het) = 0.50), although weaker in magnitude and statistically only borderline significant. Other parity related factors such as ever a full-term birth, number of births, age- and time since last birth were associated only with ER+PR+ malignancies, however no statistical heterogeneity between breast cancer subtypes was observed. Breastfeeding and OC use were generally not associated with breast cancer subtype risk. CONCLUSION: Our study provides possible evidence that age at menarche, and time between menarche and first full-term childbirth may be associated with the etiology of both HR-negative and HR-positive malignancies, although the associations with HR-negative breast cancer were only borderline significant.

Physical activity and risk of breast cancer overall and by hormone receptor status: the European prospective investigation into cancer and nutrition.

Physical activity is associated with reduced risks of invasive breast cancer. However, whether this holds true for breast cancer subtypes defined by the estrogen receptor (ER) and the progesterone receptor (PR) status is controversial. The study included 257,805 women from the multinational EPIC-cohort study with detailed information on occupational, recreational and household physical activity and important cofactors assessed at baseline. During 11.6 years of median follow-up, 8,034 incident invasive breast cancer cases were identified. Data on ER, PR and combined ER/PR expression were available for 6,007 (67.6%), 4,814 (54.2%) and 4,798 (53.9%) cases, respectively. Adjusted hazard ratios (HR) were estimated by proportional hazards models. Breast cancer risk was inversely associated with moderate and high levels of total physical activity (HR = 0.92, 95% confidence interval (CI): 0.86-0.99, HR = 0.87, 95%-CI: 0.79-0.97, respectively; p-trend = 0.002), compared to the lowest quartile. Among women diagnosed with breast cancer after age 50, the largest risk reduction was found with highest activity (HR = 0.86, 95%-CI: 0.77-0.97), whereas for cancers diagnosed before age 50 strongest associations were found for moderate total physical activity (HR = 0.78, 95%-CI: 0.64-0.94). Analyses by hormone receptor status suggested differential associations for total physical activity (p-heterogeneity = 0.04), with a somewhat stronger inverse relationship for ER+/PR+ breast tumors, primarily driven by PR+ tumors (p-heterogeneity < 0.01). Household physical activity was inversely associated with ER-/PR- tumors. The results of this largest prospective study on the protective effects of physical activity indicate that moderate and high physical activity are associated with modest decreased breast cancer risk. Heterogeneities by receptor status indicate hormone-related mechanisms.

Height, age at menarche and risk of hormone receptor-positive and -negative breast cancer: a cohort study.

Associations of breast cancer overall with indicators of exposures during puberty are reasonably well characterized; however, uncertainty remains regarding the associations of height, leg length, sitting height and menarcheal age with hormone receptor-defined malignancies. Within the European Prospective Investigation into Cancer and Nutrition cohort, Cox proportional hazards models were used to describe the relationships of adult height, leg length and sitting height and age at menarche with risk of estrogen and progesterone receptor negative (ER-PR-) (n = 990) and ER+PR+ (n = 3,524) breast tumors. Height as a single risk factor was compared to a model combining leg length and sitting height. The possible interactions of height, leg length and sitting height with menarche were also analyzed. Risk of both ER-PR- and ER+PR+ malignancies was positively associated with standing height, leg length and sitting height and inversely associated with increasing age at menarche. For ER+PR+ disease, sitting height (hazard ratios: 1.14[95% confidence interval: 1.08-1.20]) had a stronger risk association than leg length (1.05[1.00-1.11]). In comparison, for ER-PR- disease, no distinct differences were observed between leg length and sitting height. Women who were tall and had an early menarche (≤13 years) showed an almost twofold increase in risk of ER+PR+ tumors but no such increase in risk was observed for ER-PR- disease. Indicators of exposures during rapid growth periods were associated with risks of both HR-defined breast cancers. Exposures during childhood promoting faster development may establish risk associations for both HR-positive and -negative malignancies. The stronger associations of the components of height with ER+PR+ tumors among older women suggest possible hormonal links that could be specific for postmenopausal women.

Prospective study on physical activity and risk of in situ breast cancer.

BACKGROUND: Physical activity has been identified as protective factor for invasive breast cancer risk, whereas comparable studies on in situ carcinoma are rare. METHODS: The study included data from 283,827 women of the multinational European Prospective Investigation into C7ancer and Nutrition (EPIC)-cohort study. Detailed information on different types of physical activity conducted during the prior year, such as occupational, recreational, and household activity, as well as on important cofactors, was assessed at baseline. Adjusted HRs for in situ breast cancer were estimated by Cox proportional hazards models. RESULTS: During a median follow-up period of 11.7 years, 1,059 incidents of breast carcinoma in situ were identified. In crude and adjusted multivariable models, no associations were found for occupational, household, and recreational physical activity. Furthermore, total physical activity was not associated with risk of in situ breast cancer. Comparing moderately inactive, moderately active, and active participants with inactive study participants resulted in adjusted HRs of 0.99 [95% confidence interval (CI), 0.83-1.19], 0.99 (95% CI, 0.82-1.20), and 1.07 (95% CI, 0.81-1.40), respectively (P value of trend test: 0.788). No inverse associations were found in any substrata defined by age at diagnosis or body mass index (BMI) status. CONCLUSIONS: In this large prospective study, we did not find any evidence of an association between physical activity and in situ breast cancer risk. If not by chance, the contrast between our results for carcinoma in situ and the recognized inverse association for invasive breast cancer suggests that physical activity may have stronger effects on proliferation and late stage carcinogenesis.

Adiposity, hormone replacement therapy use and breast cancer risk by age and hormone receptor status: a large prospective cohort study.

INTRODUCTION: Associations of hormone-receptor positive breast cancer with excess adiposity are reasonably well characterized; however, uncertainty remains regarding the association of body mass index (BMI) with hormone-receptor negative malignancies, and possible interactions by hormone replacement therapy (HRT) use. METHODS: Within the European EPIC cohort, Cox proportional hazards models were used to describe the relationship of BMI, waist and hip circumferences with risk of estrogen-receptor (ER) negative and progesterone-receptor (PR) negative (n = 1,021) and ER+PR+ (n = 3,586) breast tumors within five-year age bands. Among postmenopausal women, the joint effects of BMI and HRT use were analyzed. RESULTS: For risk of ER-PR- tumors, there was no association of BMI across the age bands. However, when analyses were restricted to postmenopausal HRT never users, a positive risk association with BMI (third versus first tertile HR = 1.47 (1.01 to 2.15)) was observed. BMI was inversely associated with ER+PR+ tumors among women aged ≤49 years (per 5 kg/m2 increase, HR = 0.79 (95%CI 0.68 to 0.91)), and positively associated with risk among women ≥65 years (HR = 1.25 (1.16 to 1.34)). Adjusting for BMI, waist and hip circumferences showed no further associations with risks of breast cancer subtypes. Current use of HRT was significantly associated with an increased risk of receptor-negative (HRT current use compared to HRT never use HR: 1.30 (1.05 to 1.62)) and positive tumors (HR: 1.74 (1.56 to 1.95)), although this risk increase was weaker for ER-PR- disease (Phet = 0.035). The association of HRT was significantly stronger in the leaner women (BMI ≤22.5 kg/m2) than for more overweight women (BMI ≥25.9 kg/m2) for, both, ER-PR- (HR: 1.74 (1.15 to 2.63)) and ER+PR+ (HR: 2.33 (1.84 to 2.92)) breast cancer and was not restricted to any particular HRT regime. CONCLUSIONS: An elevated BMI may be positively associated with risk of ER-PR- tumors among postmenopausal women who never used HRT. Furthermore, postmenopausal HRT users were at an increased risk of ER-PR- as well as ER+PR+ tumors, especially among leaner women. For hormone-receptor positive tumors, but not for hormone-receptor negative tumors, our study confirms an inverse association of risk with BMI among young women of premenopausal age. Our data provide evidence for a possible role of sex hormones in the etiology of hormone-receptor negative tumors.