Isabelle Romieu1, Carine Biessy2, Maureen Joffe3,4, Herbert Cubasch3,5, Shane Norris4, Hester H Vorster6, Christine Taljaard-Krugell6, Marc J Gunter2, Sabina Rinaldi7. 1. Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Mexico. 2. Section of Nutrition and Metabolism, International Agency for Research On Cancer, 150, Cours Albert Thomas, 69008, Lyon, France. 3. Non-Communicable Diseases Research Division, Wits Health Consortium (PTY) Ltd, Johannesburg, South Africa. 4. MRC Developmental Pathways To Health Research Unit, Department of Pediatrics, Faculty of Health, Sciences, University of Witwatersrand, Johannesburg, South Africa. 5. Department of Surgery, Faculty of Health Sciences, University of Witwatersrand, Johannesburg, South Africa. 6. Centre of Excellence for Nutrition, North-West University, Potchefstroom, South Africa. 7. Section of Nutrition and Metabolism, International Agency for Research On Cancer, 150, Cours Albert Thomas, 69008, Lyon, France. rinaldis@iarc.fr.
Abstract
PURPOSE: Breast cancer (BC) is increasing in black South African women, but few studies have investigated its risk factors. METHODS: We conducted an analysis of reproductive factors and BC risk in the South African Breast Cancer (SABC) study-a population-based case-control study of black South African women from Soweto that included 399 cases and 399 matched controls. Information on lifestyle and reproductive history was obtained by interviews. Conditional logistic regression was used to determine the association of reproductive factors with BC, adjusting for potential confounding factors. RESULTS: Seventy-five percent of all BC cases were ER+, 66% PR+, 30% HER2+, and 16% TN. None of the reproductive variables were associated with BC overall or by subtype in the overall population, nor in pre- (n = 135 cases) or in post-menopausal women separately. In HIV-negative pre-menopausal women (n = 97 cases), later age at first pregnancy and longer time between menarche and first full-time pregnancy were inversely related to BC risk (OR 0.89 (95% CI 0.82-0.97; and 0.93 95% CI 0.86-1.01, respectively). CONCLUSION: In this population of black South African women, reproductive factors were not associated with BC risk.
PURPOSE:Breast cancer (BC) is increasing in black South African women, but few studies have investigated its risk factors. METHODS: We conducted an analysis of reproductive factors and BC risk in the South African Breast Cancer (SABC) study-a population-based case-control study of black South African women from Soweto that included 399 cases and 399 matched controls. Information on lifestyle and reproductive history was obtained by interviews. Conditional logistic regression was used to determine the association of reproductive factors with BC, adjusting for potential confounding factors. RESULTS: Seventy-five percent of all BC cases were ER+, 66% PR+, 30% HER2+, and 16% TN. None of the reproductive variables were associated with BC overall or by subtype in the overall population, nor in pre- (n = 135 cases) or in post-menopausal women separately. In HIV-negative pre-menopausal women (n = 97 cases), later age at first pregnancy and longer time between menarche and first full-time pregnancy were inversely related to BC risk (OR 0.89 (95% CI 0.82-0.97; and 0.93 95% CI 0.86-1.01, respectively). CONCLUSION: In this population of black South African women, reproductive factors were not associated with BC risk.
Entities:
Keywords:
Black South African women; Breast cancer; Reproductive factors
Authors: Jonine D Figueroa; Brittny C Davis Lynn; Lawrence Edusei; Nicholas Titiloye; Ernest Adjei; Joe-Nat Clegg-Lamptey; Joel Yarney; Beatrice Wiafe-Addai; Baffour Awuah; Maire A Duggan; Seth Wiafe; Kofi Nyarko; Francis Aitpillah; Daniel Ansong; Stephen M Hewitt; Thomas Ahearn; Montserrat Garcia-Closas; Louise A Brinton Journal: Int J Cancer Date: 2020-03-13 Impact factor: 7.316