Case-Control Study of Body Size and Breast Cancer Risk in Nigerian Women

Abstract

Previous studies have shown that weight is inversely associated with premenopausal breast cancer and positively associated with postmenopausal disease. Height has been shown to be positively correlated with breast cancer risk, but the association was not conclusive for premenopausal women. These previous studies were conducted primarily in Western countries, where height is not limited by nutritional status during childhood. The authors assessed the association between breast cancer and anthropometric measures in the Nigerian Breast Cancer Study (Ibadan, Nigeria). Between 1998 and 2009, 1,233 invasive breast cancer cases and 1,101 controls were recruited. The multivariate-adjusted odds ratio for the highest quartile group of height relative to the lowest was 2.03 (95% confidence interval (CI): 1.51, 2.72; P-trend < 0.001), with an odds ratio of 1.22 (95% CI: 1.14, 1.32) for each 5-cm increase, with no difference by menopausal status. Comparing women with a body mass index in the lowest quartile group, the adjusted odds ratio for women in the highest quartile category was 0.72 (95% CI: 0.54, 0.94; P-trend = 0.009) for premenopausal and postmenopausal women. Influence of height on breast cancer risk was quite strong in this cohort of indigenous Africans, which suggests that energy intake during childhood may be important in breast cancer development.

Breast cancer in Sub-Saharan Africa: opportunities for prevention

“…In the largest study, involving 1,233 Nigerian breast cancer cases [25], body mass index (BMI) was inversely related to risk. However, given the typical late presentation of disease among African women, such a finding must be cautiously interpreted and may reflect weight loss due to illness.…”

“…Hip circumference has been noted to be inversely related to risk [26]. In one of these studies, the relation with WHR persisted after adjustment for obesity [25]. Tallness has also been found to be a significant risk factor for breast cancer in two Nigerian studies [17, 25].…”

An Epidemiologic Investigation of Physical Activity and Breast Cancer Risk in Africa

“…The study setting and design of the Nigeria site were described in detail elsewhere (17,18). Participants from the three study sites were recruited as described below: In Nigeria, breast cancer cases were identified through the surgical oncology and radiotherapy units of the University College Hospital (UCH) in Ibadan, Nigeria which serves a population of 3 million and is the main referral center for other hospitals and thus treats the majority of the breast cancer cases in the region.…”

Obesity and the Risk for Premenopausal and Postmenopausal Breast Cancer

“…4, 5). Since 2000, several larger studies, including prospective cohort (6)(7)(8)(9)(10)(11)(12) and case-control studies (13)(14)(15)(16) and a pooled analysis of 7 prospective cohorts (17), have examined this question in diverse populations (Table 1). For premenopausal women, both prospective cohort and case-control studies consistently report a modest (20%-40%) decreased risk of breast cancer in obese women compared with normal weight women, but similar risks for overweight and normal weight women.…”

“…For postmenopausal women, prospective cohort studies have associated increasing BMI with increasing breast cancer incidence, with some heterogeneity in the strength of this trend. Recent case-control studies in postmenopausal women, however, suggest no relationship between BMI and breast cancer risk (14)(15)(16).…”