Alcohol Consumption and Breast Cancer Risk among Women in Three Sub-Saharan African Countries

Background: Alcohol drinking is linked to the development of breast cancer. However, there is little knowledge about the impact of alcohol consumption on breast cancer risk among African women.Methods: We conducted a case-control study among 2,138 women with invasive breast cancer and 2,589 controls in Nigeria, Cameroon, and Uganda from 1998 to 2013. A structured questionnaire was used to collect information on alcohol consumption, defined as consuming alcoholic beverages at least once a week for six months or more. Logistic regression was used to estimate adjusted odds ratio (aOR) and 95% confidence interval (CI).Results: Among healthy controls, the overall alcohol consumption prevalence was 10.4%, and the prevalence in Nigeria, Cameroon, and Uganda were 5.0%, 34.6%, and 50.0%, respectively. Cases were more likely to have consumed alcohol (aOR = 1.62, 95% CI: 1.33–1.97). Both past (aOR = 1.54; 95% CI: 1.19–2.00) and current drinking (aOR = 1.71; 95% CI: 1.30–2.23) were associated with breast cancer risk. A dose-response relationship was observed for duration of alcohol drinking (P-trend Conclusion: We found a positive relationship between alcohol consumption and breast cancer risk, suggesting that this modifiable risk factor should be addressed in breast cancer prevention programs in Africa.</p

Alcohol Consumption and Breast Cancer Risk among Women in Three Sub-Saharan African Countries

<div><p>Background</p><p>Alcohol drinking is linked to the development of breast cancer. However, there is little knowledge about the impact of alcohol consumption on breast cancer risk among African women.</p><p>Methods</p><p>We conducted a case-control study among 2,138 women with invasive breast cancer and 2,589 controls in Nigeria, Cameroon, and Uganda from 1998 to 2013. A structured questionnaire was used to collect information on alcohol consumption, defined as consuming alcoholic beverages at least once a week for six months or more. Logistic regression was used to estimate adjusted odds ratio (aOR) and 95% confidence interval (CI).</p><p>Results</p><p>Among healthy controls, the overall alcohol consumption prevalence was 10.4%, and the prevalence in Nigeria, Cameroon, and Uganda were 5.0%, 34.6%, and 50.0%, respectively. Cases were more likely to have consumed alcohol (aOR = 1.62, 95% CI: 1.33–1.97). Both past (aOR = 1.54; 95% CI: 1.19–2.00) and current drinking (aOR = 1.71; 95% CI: 1.30–2.23) were associated with breast cancer risk. A dose-response relationship was observed for duration of alcohol drinking (<i>P</i>-trend <0.001), with 10-year increase of drinking associated with a 54% increased risk (95% CI: 1.29–1.84).</p><p>Conclusion</p><p>We found a positive relationship between alcohol consumption and breast cancer risk, suggesting that this modifiable risk factor should be addressed in breast cancer prevention programs in Africa.</p></div

Multivariable logistic regression analyses of alcohol consumption and breast cancer risk among women in Nigeria, Cameroon and Uganda, 1998–2013, using data after multiple imputation (N = 4727).

†<p>Adjusted for age at diagnosis or interview (categorical), ethnicity, education (categorical), age at menarche (categorical), number of live births (categorical), age at first live birth (categorical), menopausal status, family history of breast cancer, benign breast disease, hormonal contraceptive use, BMI (continuous), and height (continuous);</p>‡<p>Adjusted for the above variables and study site.</p><p>Includes drinkers who drink a combination of alcoholic beverages.</p><p>Multivariable logistic regression analyses of alcohol consumption and breast cancer risk among women in Nigeria, Cameroon and Uganda, 1998–2013, using data after multiple imputation (N = 4727).</p

Patterns of alcohol consumption among women in Nigeria, Cameroon and Uganda, 1998–2013

†<p>Among drinkers.</p><p>Includes drinkers who drink a combination of alcoholic beverages, percentages may not add up to 100%.</p><p>Patterns of alcohol consumption among women in Nigeria, Cameroon and Uganda, 1998–2013</p

Stratified analyses of alcohol consumption and breast cancer risk among women in Nigeria, Cameroon, and Uganda using data after multiple imputation, 1998–2013.

<p>*Adjusted for all other variables listed in this table as well as age at first live birth and study site.</p><p>Stratified analyses of alcohol consumption and breast cancer risk among women in Nigeria, Cameroon, and Uganda using data after multiple imputation, 1998–2013.</p

Demographics of women with invasive breast cancer (cases) and those without (controls) in Nigeria, Cameroon and Uganda, 1998–2013.

<p><b>Note</b>: Numbers in parentheses are proportions (%). SD: standard deviation.</p>a<p>Proportions or means for the controls are adjusted values based on the age distribution of cases; <i>P</i>-values were also age-adjusted in logistic regressions.</p>b<p>Among parous women.</p><p>Demographics of women with invasive breast cancer (cases) and those without (controls) in Nigeria, Cameroon and Uganda, 1998–2013.</p

Percentage of healthy controls who were current drinkers by age group in the three African countries.

<p>Percentage of healthy controls who were current drinkers by age group in the three African countries.</p