The South African breast cancer and HIV outcomes study: Profiling the cancer centres and cohort characteristics, diagnostic pathways, and treatment approaches.

The South African Breast Cancer and HIV Outcomes prospective cohort (SABCHO) study was established to investigate survival determinants among HIV-positive and HIV-negative SA women with breast cancer. This paper describes common and unique characteristics of the cancer centres and their participants, examining disparities in pathways to diagnosis, treatment resources and approaches adopted to mitigate resource constraints. The Johannesburg (Jhb), Soweto (Sow), and Durban (Dbn) sites treat mainly urban, relatively better educated and more socioeconomically advantaged patients whereas the Pietermaritzburg (Pmb) and Empangeni (Emp) sites treat predominantly rural, less educated and more impoverished communities The Sow, Jhb, and Emp sites had relatively younger patients (mean ages 54 ±14.5, 55±13.7 and 54±14.3 respectively), whereas patients at the Dbn and Pmb sites, with greater representation of Asian Indian women, were relatively older (mean age 57 ±13.9 and 58 ±14.6 respectively). HIV prevalence among the cohort was high, ranging from 15%-42%, (Cohort obesity (BMI ≥ 30 kg/m2) at 60%, self-reported hypertension (41%) and diabetes (13%). Direct referral of patients from primary care clinics to cancer centre occurred only at the Sow site which uniquely ran an open clinic and where early stage (I and II) proportions were highest at 48.5%. The other sites relied on indirect patient referral from regional hospitals where significant delays in diagnostics occurred and early-stage proportions were a low (15%- 37.3%). The Emp site referred patients for all treatments to the Dbn site located 200km away; the Sow site provided surgery and endocrine treatment services but referred patients to the Jhb site 30 Km away for chemo- and radiation therapy. The Jhb, Dbn and Pmb sites all provided complete oncology treatment services. All treatment centres followed international guidelines for their treatment approaches. Findings may inform policy interventions to address national and regional disparities in breast cancer care.

The Impact of HIV Infection on Neoadjuvant and Adjuvant Chemotherapy Relative Dose Intensity in South African Patients with Breast Cancer.

INTRODUCTION: In the South African Breast Cancer and HIV Outcomes (SABCHO) study, we previously found that breast cancer patients living with HIV and treated with neoadjuvant chemotherapy achieve lower rates of complete pathologic response than patients without HIV. We now assess the impact of comorbid HIV on receipt of timely and complete neoadjuvant and adjuvant chemotherapy. MATERIALS AND METHODS: Since June 2015, the SABCHO study has collected data on women diagnosed with breast cancer at 6 South African hospitals. We selected a sample of participants with stages I-III cancer who received ≥2 doses of neoadjuvant or adjuvant chemotherapy. Data on chemotherapies prescribed and received, filgrastim receipt, and laboratory values measured during treatment were captured from patients' medical records. We calculated the mean relative dose intensity (RDI) for all prescribed chemotherapies. We tested for association between full regimen RDI and HIV status, using linear regression to control for demographic and clinical covariates, and for association of HIV with laboratory abnormalities. RESULTS: The 166 participants living with HIV and 159 without HIV did not differ in median chemotherapy RDI: 0.89 (interquartile range (IQR) 0.77-0.95) among those living with HIV and 0.87 (IQR 0.77-0.94) among women without HIV. Patients living with HIV experienced more grade 3+ anemia and leukopenia than those without HIV (anemia: 10.8% vs. 1.9%, P = .001; leukopenia: 8.4% vs. 1.9%, P = .008) and were more likely to receive filgrastim (24.7% vs. 10.7%, P = .001). CONCLUSIONS: HIV status did not impact neoadjuvant or adjuvant chemotherapy RDI, although patients with breast cancer living with HIV experienced more myelotoxicity during treatment.

Drivers of disparities in stage at diagnosis among women with breast cancer: South African breast cancers and HIV outcomes cohort.

OBJECTIVE: In low- and middle-income countries (LMICs), advanced-stage diagnosis of breast cancer (BC) is common, and this contributes to poor survival. Understanding the determinants of the stage at diagnosis will aid in designing interventions to downstage disease and improve survival from BC in LMICs. METHODS: Within the South African Breast Cancers and HIV Outcomes (SABCHO) cohort, we examined factors affecting the stage at diagnosis of histologically confirmed invasive breast cancer at five tertiary hospitals in South Africa (SA). The stage was assessed clinically. To examine the associations of the modifiable health system, socio-economic/household and non-modifiable individual factors, hierarchical multivariable logistic regression with odds of late-stage at diagnosis (stage III-IV), was used. RESULTS: The majority (59%) of the included 3497 women were diagnosed with late-stage BC disease. The effect of health system-level factors on late-stage BC diagnosis was consistent and significant even when adjusted for both socio-economic- and individual-level factors. Women diagnosed in a tertiary hospital that predominantly serves a rural population were 3 times (OR = 2.89 (95% CI: 1.40-5.97) as likely to be associated with late-stage BC diagnosis when compared to those diagnosed at a hospital that predominantly serves an urban population. Taking more than 3 months from identifying the BC problem to the first health system entry (OR = 1.66 (95% CI: 1.38-2.00)), and having luminal B (OR = 1.49 (95% CI: 1.19-1.87)) or HER2-enriched (OR = 1.64 (95% CI: 1.16-2.32)) molecular subtype as compared to luminal A, were associated with a late-stage diagnosis. Whilst having a higher socio-economic level (a wealth index of 5) reduced the probability of late-stage BC at diagnosis, (OR = 0.64 (95% CI: 0.47-0.85)). CONCLUSION: Advanced-stage diagnosis of BC among women in SA who access health services through the public health system was associated with both modifiable health system-level factors and non-modifiable individual-level factors. These may be considered as elements in interventions to reduce the time to diagnosis of breast cancer in women.

The Impact of Breast Cancer Treatment Delays on Survival Among South African Women.

BACKGROUND: In high-income settings, delays from breast cancer (BC) diagnosis to initial treatment worsen overall survival (OS). We examined how time to BC treatment initiation (TTI) impacts OS in South Africa (SA). METHODS: We evaluated women enrolled in the South African BC and HIV Outcomes study between July 1, 2015 and June 30, 2019, selecting women with stages I-III BC who received surgery and chemotherapy. We constructed a linear regression model estimating the impact of sociodemographic and clinical factors on TTI and separate multivariable Cox proportional hazard models by first treatment (surgery and neoadjuvant chemotherapy (NAC)) assessing the effect of TTI (in 30-day increments) on OS. RESULTS: Of 1260 women, 45.6% had upfront surgery, 54.4% had NAC, and 19.5% initiated treatment >90 days after BC diagnosis. Compared to the surgery group, more women in the NAC group had stage III BC (34.8% vs 81.5%). Living further away from a hospital and having hormone receptor positive (vs negative) BC was associated with longer TTI (8 additional days per 100 km, P = .003 and 8 additional days, P = .01, respectively), while Ki67 proliferation index >20 and upfront surgery (vs NAC) was associated with shorter TTI (12 and 9 days earlier; P = .0001 and.007, respectively). Treatment initiation also differed among treating hospitals (P < .0001). Additional 30-day treatment delays were associated with worse survival in the surgery group (HR 1.11 [95%CI 1.003-1.22]), but not in the NAC group. CONCLUSIONS: Delays in BC treatment initiation are common in SA public hospitals and are associated with worse survival among women treated with upfront surgery.

Impact of HIV infection on survival among women with stage I-III breast cancer: Results from the South African breast cancer and HIV outcomes study.

In some countries of sub-Saharan Africa, the prevalence of HIV exceeds 20%; in South Africa, 20.4% of people are living with HIV. We examined the impact of HIV infection on the overall survival (OS) of women with nonmetastatic breast cancer (BC) enrolled in the South African Breast Cancer and HIV Outcomes (SABCHO) study. We recruited women with newly diagnosed BC at six public hospitals from 1 July 2015 to 30 June 2019. Among women with stages I-III BC, we compared those with and without HIV infection on sociodemographic, clinical, and treatment factors. We analyzed the impact of HIV on OS using multivariable Cox proportional hazard models. Of 2367 women with stages I-III BC, 499 (21.1%) had HIV and 1868 (78.9%) did not. With a median follow-up of 29 months, 2-year OS was poorer among women living with HIV (WLWH) than among HIV-uninfected women (72.4% vs 80.1%, P < .001; adjusted hazard ratio (aHR) 1.49, 95% confidence interval (CI) = 1.22-1.83). This finding was consistent across age groups ≥45 years and <45 years, stage I-II BC and stage III BC, and ER/PR status (all P < .03). Both WLWH with <50 viral load copies/mL and WLWH with ≥50 viral load copies/mL had poorer survival than HIV-uninfected BC patients [aHR: 1.35 (1.09-1.66) and 1.54 (1.20-2.00), respectively], as did WLWH who had ≥200 CD4+ cells/mL at diagnosis [aHR: 1.39 (1.15-1.67)]. Because receipt of antiretroviral therapy has become widespread, WLWH is surviving long enough to develop BC; more research is needed on the causes of their poor survival.

Impact of HIV infection on overall survival among women with stage IV breast cancer in South Africa.

PURPOSE: Advanced breast cancer (BC) at diagnosis is common in sub-Saharan Africa (SSA), including among women living with HIV (WLWH). In public hospitals across South Africa (SA), 10-15% of women present with stage IV BC, compared to < 5% in the United States (US); 20% of new BC diagnoses in SA are in WLWH. We evaluated the impact of HIV on overall survival (OS) among women with stage IV BC. METHODS: We conducted a prospective cohort study of women diagnosed with stage IV BC between February 2, 2015 and September 18, 2019 at six public hospitals in SA. Multivariate Cox regression models were used to estimate the association between HIV status and OS. RESULTS: Among 550 eligible women, 147 (26.7%) were WLWH. Compared to HIV-negative BC patients, WLWH were younger (median age 45 vs. 60 years, p < 0.001), predominantly black (95.9% vs. 77.9%, p < 0.001), and more likely to have hormone receptor-negative (hormone-negative) BC (32.7% vs. 22.6%, p = 0.016). Most women received systemic cancer-directed therapy (80.1%). HIV status was not associated with treatment or OS (Hazard Ratio (HR) 1.13 [95%CI 0.89-1.44]). On exploratory subgroup analysis, WLWH and hormone-negative BC had shorter OS compared to HIV-uninfected women (1-year OS: 27.1% vs. 48.8%, p = 0.003; HR 1.94 [95%CI 1.27-2.94]; p = 0.002), which was not observed for hormone receptor-positive BC. CONCLUSION: HIV status was not associated with worse OS in women with stage IV BC in SA and cannot account for the poor survival in this cohort. Subgroup analysis revealed that WLWH with hormone-negative BC had worse OS, which warrants further investigation.