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

Abstract

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.

• Authors: Mariana Brandão, Assucena Guisseve, Albertino Damasceno, Genoveva Bata, Carla Silva-Matos, Matos Alberto, Josefo Ferro, Carlos Garcia, Clésio Zaqueu, Cesaltina Lorenzoni, Dina Leitão, Otília Soares, Alberto Gudo-Morais, Fernando Schmitt, Samantha Morais, Satish Tulsidás, Carla Carrilho, Nuno Lunet
• Journal: Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology (Cancer Epidemiol Biomarkers Prev) Vol. 30 Issue 6 Pg. 1250-1259 (06 2021) ISSN: 1538-7755 [Electronic] United States
• PMID: 33849971 (Publication Type: Journal Article, Observational Study, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: ©2021 American Association for Cancer Research.

Topics

• Adult
• Aged
• Aged, 80 and over
• Biopsy, Fine-Needle
• Body Mass Index
• Breast (pathology)
• Breast Neoplasms (diagnosis, epidemiology, pathology)
• Case-Control Studies
• Educational Status
• Female
• Humans
• Incidence
• Middle Aged
• Mozambique (epidemiology)
• Obesity (epidemiology)
• Prevalence
• Risk Assessment (statistics & numerical data)
• Risk Factors
• Young Adult