Risk Factors for Breast Cancer, Overall and by Tumor Subtype, among Women from Mozambique, Sub-Saharan Africa.

BACKGROUND: Breast cancer incidence is rising in Africa, but there are scare data regarding risk factors in this region. We assessed the relation between risk factors and the occurrence of breast cancer, overall and by tumor subtype in women from Mozambique. METHODS: The associations between education, number of births, height, weight, body mass index (BMI), and breast cancer risk among 138 cases (participants from the Moza-BC cohort) and 638 controls from the general population (from a World Health Organization stepwise approach to surveillance survey), recruited during 2014 to 2017, were investigated. Adjusted ORs (aOR) and 95% confidence intervals (CI) were estimated using multivariable logistic regression. RESULTS: Multiparity (≥6 vs. 0-1 live births) was a protective factor for the development of hormone receptor (HR)-positive (aOR = 0.22; 95% CI, 0.08-0.64) and HR-positive/HER2-negative tumors (aOR = 0.20; 95% CI, 0.06-0.68), whereas a higher educational level (≥8 vs. 0 schooling years) increased breast cancer risk across all subtypes (overall aOR = 1.98; 95% CI, 1.04-3.80). Higher weight and BMI were associated with a higher breast cancer risk among postmenopausal women (per 1-kg increase: aOR = 1.05; 95% CI, 1.02-1.08; per 1-kg/m2 increase: aOR = 1.11; 95% CI, 1.04-1.18, respectively), but were protective in premenopausal women (aOR = 0.98; 95% CI, 0.96-0.99; aOR = 0.95; 95% CI, 0.91-0.99, respectively), regardless of subtype. Higher height increased the risk of HR-negative tumors in postmenopause (per 10-cm increase: aOR = 2.81; 95% CI, 1.41-6.03). CONCLUSION: These results demonstrate the etiological heterogeneity of breast cancer among native African women, namely regarding the differential effect of multiparity, education, and body parameters in breast cancer risk. IMPACT: As the prevalence of obesity grows, these findings are important to inform public health policies on cancer prevention, by highlighting obesity as a modifiable risk factor for breast cancer among African women.

Comparing the cost of non-metastatic breast cancer care in a low-income vs a high-income country: A plea for an optimal allocation of health resources in Sub-Saharan Africa.

Breast cancer incidence is rising in low-income countries, but there is limited information regarding health resource allocation for its care. We assessed the cost of care during the first three years after diagnosis in a low-income country (Mozambique; n = 162 women) and compared it with a high-income country (Portugal, n = 703 women). Local currency prices were converted to 2019 international dollars (Int$). In Mozambique, the median cost was lower than in Portugal (2888 vs 18,533 Int$, respectively) and did not vary across stage or tumor subtype. These findings may help improving resource allocation for breast cancer care in Sub-Saharan Africa, despite reflecting an underfunding of treatment in this setting.

Survival Impact and Cost-Effectiveness of a Multidisciplinary Tumor Board for Breast Cancer in Mozambique, Sub-Saharan Africa.

BACKGROUND: Despite the international endorsement of multidisciplinary tumor boards (MTBs) for breast cancer care, implementation is suboptimal worldwide, and evidence regarding their effectiveness in developing countries is lacking. We assessed the impact on survival and the cost-effectiveness of implementing an MTB in Mozambique, sub-Saharan Africa. MATERIALS AND METHODS: This prospective cohort study included 205 patients with breast cancer diagnosed between January 2015 and August 2017 (98 before and 107 after MTB implementation), followed to November 2019. Pre- and post-MTB implementation subcohorts were compared for clinical characteristics, treatments, and overall survival. We used hazard ratios and 95% confidence intervals (CI), computed by Cox proportional hazards regression. The impact of MTB implementation on the cost per quality-adjusted life year (QALY) was estimated from the provider perspective. RESULTS: We found no significant differences between pre- and post-MTB subcohorts regarding clinical characteristics or treatments received. Among patients with early breast cancer (stage 0-III; n = 163), the 3-year overall survival was 48.0% (95% CI, 35.9-59.1) in the pre-MTB and 73.0% (95% CI, 61.3-81.6) in the post-MTB subcohort; adjusted hazard ratio, 0.47 (95% CI, 0.27-0.81). The absolute 3-year mean cost increase was $119.83 per patient, and the incremental cost-effectiveness ratio was $802.96 per QALY, corresponding to 1.6 times the gross domestic product of Mozambique. CONCLUSION: The implementation of a MTB in Mozambique led to a 53% mortality decrease among patients with early breast cancer, and it was cost-effective. These findings highlight the feasibility of implementing this strategy and the need for scaling-up MTBs in developing countries, as a way to improve patient outcomes. IMPLICATIONS FOR PRACTICE: Currently, more than half of the deaths from breast cancer in the world occur in developing countries. Strategies that optimize care and that are adjusted for available resources are needed to improve the outcomes of patients with breast cancer in these regions. The discussion of cases at multidisciplinary tumor boards (MTBs) may improve survival outcomes, but implementation is suboptimal worldwide, and evidence regarding their effectiveness in developing countries is lacking. This study evaluated the impact of implementing an MTB on the care and survival of patients with breast cancer in Mozambique, sub-Saharan Africa and its cost-effectiveness in this low-income setting.

Breast cancer subtypes: implications for the treatment and survival of patients in Africa-a prospective cohort study from Mozambique.

BACKGROUND: Data regarding breast cancer epidemiology, treatment and survival in Africa are scarce. We aimed to assess the distribution of breast cancer subtypes in Mozambique and its impact on patients' treatment and survival. The concordance of biomarker assessment between cytological and histological samples was also evaluated. METHODS: Prospective cohort study including 210 patients diagnosed between January 2015 and August 2017, followed to November 2019. Clinicopathological characteristics, treatment, 3-year overall survival (OS) and disease-free survival (DFS) were compared across classic tumour subtypes (oestrogen receptor (ER)-positive/human epidermal growth factor receptor 2 (HER2)-negative, HER2-positive and triple-negative breast cancer (TNBC)) and surrogate intrinsic subtypes (St. Gallen classification). Concordance was measured using Cohen's κ statistics. RESULTS: A total of 51% of patients had ER-positive/HER2-negative tumours, 24% HER2-positive and 25% TNBC. Concordance between cytological and histological samples regarding ER and HER2 status was substantial (κ=0.762 and κ=0.603, respectively). There were no significant differences across subtypes regarding clinical characteristics and treatment, except for HIV positivity and high histological grade (more prevalent among TNBC) or endocrine therapy (higher use among ER-positive/HER2-negative and HER2-positive patients). Three-year OS was 52.5% (95% CI, 44.3% to 60.0%), being higher in ER-positive/HER2-negative (61.1%) compared with HER2-positive (53.2%) and TNBC (31.9%) patients. Adjusted HRs were 1.96 (95% CI, 1.13 to 3.39) among HER2-positive and 3.10 (95% CI, 1.81 to 5.31) among TNBC versus ER-positive/HER2-negative patients. Three-year DFS was 46.6% (95% CI, 38.0% to 54.8%), being lower among TNBC versus ER-positive/HER2-negative patients (HR 2.91; 95% CI, 1.64 to 5.16). Results were similar between surrogate intrinsic subtypes. CONCLUSION: There was a high proportion of HER2-positive and TNBC among Mozambican patients and their survival was poor compared with ER-positive/HER2-negative patients, partly due to the limited treatment options. A systematic assessment of ER, PR and HER2 status is feasible and may help tailoring and optimise the treatment of patients with breast cancer in low-resource settings, potentially leading to survival gains in this underserved population.