Socio-economic status and the risk of breast cancer among Nigerian women: a case control study.

Introduction: an increased risk of breast cancer associated with high socio-economic status has been reported in high income countries. A few available African studies have reported inconsistent findings using different single socio-economic measures. Our aim was to investigate the association between socio-economic status and the risk of breast cancer among Nigerian women based on a range of socio-economic status measures. Methods: we conducted a hospital-based case-control study involving participants from five hospitals in Lagos and Abuja. Women were interviewed in-person between October 2016 and May 2017 using a semi-structured questionnaire. Socio-economic status was assessed based on education, occupation, income, wealth, and socio-economic index. Multivariable logistic regression was applied in data analysis using Statistical Package for Social Sciences (SPSS) version 23. Level of significance was based on 95% confidence interval or p-values less than 0.05. Results: we recruited 379 histologically confirmed breast cancer cases and 403 controls. Following full adjustments, breast cancer risk reduced as socio-economic index increased (p for trend=0.028). Although women in the highest categories of educational attainment [Odds ratio (OR)=0.21, 95% confidence interval (CI): 0.09, 0.53], and personal income (OR=0.37, 95% CI: 0.19, 0.72) had a reduced risk of breast cancer compared to women in the lowest categories respectively after adjustments for relevant covariates, income alone exhibited a significant risk reduction following mutual adjustment for other socio-economic status measures (p for trend=0.014). Conclusion: the observed associations between high socio-economic status and lower breast cancer risk in Nigeria contrast with predominant findings in high-income countries. It suggests the need for socio-economic intervention and other preventive programmes such as improved access to screening and diagnostic services targeted at women of low socio-economic status in Nigeria.

Physical activity and the risk of breast cancer among Nigerian women.

BACKGROUND: Although physical activity has been associated with a reduced risk of breast cancer risk in high income countries (HIC), its role has not been widely studied in sub-Saharan Africa. Our aim was to investigate the association between physical activity (PA) and the risk of breast cancer in Nigeria. METHODS: We conducted a hospital-based case-control study involving participants from five hospitals in Lagos and Abuja. Women were interviewed in-person between October 2016 and May 2017 using a semi-structured questionnaire. Total PA was estimated by summing occupational, household, transport and leisure PA scores. PA was summarised as metabolic equivalents (MET) hours per week (MET-hr/wk). The putative association between breast cancer incidence and PA was analysed using multivariable logistic regression. RESULTS: 379 histologically confirmed breast cancer cases and 403 controls took part. Compared to women in the lowest categories, women in the upper middle category of total PA(adjusted OR-AOR 0.44, 95% CI: 0.27, 0.78),uppermost categories of total non-vigorous PA (AOR 0.26, 95%CI:0.09,0.75), household PA(AOR 0.0.38, 95% CI: 0.20, 0.71) and occupational PA (AOR 0.64, 95% 0.40, 1.02) had a reduced risk of breast cancer following adjustment for relevant confounders. Transport and leisure PA were not significantly associated with a reduced risk of breast cancer. CONCLUSION: The total effect of various PA related to regular activities of Nigerian women was associated with a reduced risk of breast cancer. PA especially at household and occupational environments should be promoted as part of breast cancer prevention strategy in Nigeria.

Radiotherapy waiting time in Northern Nigeria: experience from a resource-limited setting.

BACKGROUND: Access and availability of radiotherapy treatment is limited in most low- and middle-income countries, which leads to long waiting times and poor clinical outcomes. The aim of our study is to determine the magnitude of waiting times for radiotherapy in a resource-limited setting. METHODS: This is a retrospective cohort study of patients with the five most commonly treated cancers managed with radiotherapy between 2010 and 2014. Data includes diagnosis, patients' demographics and treatment provided. The waiting time was categorised into intervals (1) between diagnosis and first radiation consultation (2) First consultation to radiotherapy treatment (3) Decision-to-treat to treatment and (4) Diagnosis to treatment. RESULTS: A total of 258 cases were involved, including cervical (50%; 129/258), breast (27.5%; 71/258), nasopharynx (12.8%; 33/258), colorectal (5%; 13/258) and prostate cancers (4.7%; 12/258). Mean age was 48 (±12.9) years. Treatment with radical intent comprised 67% (178/258) of cases, while 33% (80/258) had palliative treatment. The median time from diagnosis to first radiation consultation was 40 (IQR 17-157.75) days for all the patients, with prostate cancer having the longest time - 305 days (IQR 41-393.8). The median time between the first radiation oncology consultations and first radiotherapy treatment was 130.5 (IQR 14-211.5) days; cervical cancer patients waited a median of 139 (IQR 13-195.5) days. The median time between diagnosis and first radiotherapy for breast cancer patients was 329 (IQR 207-464) days, compared to 213 (IQR 101.5-353.5) days for all the patients. CONCLUSION: The study shows that waiting time for radiotherapy in Nigeria was generally longer than what is recommended internationally. This reflects the need to improve access to radiotherapy in order to improve cancer treatment outcomes in resource-limited settings.

Body fat distribution and breast cancer risk: findings from the Nigerian breast cancer study.

PURPOSE: The relationship between overall obesity and breast cancer risk has been well recognized, but the role of central obesity in breast cancer development is uncertain. METHODS: Between 1998 and 2009, 1,233 invasive breast cancer cases and 1,101 community controls were recruited into the Nigerian Breast Cancer Study at Ibadan, Nigeria. Logistic regressions were used to calculate multivariate odds ratio (OR) and 95% confidence intervals (CI), adjusting for age, body mass index (BMI), and other known risk factors for breast cancer. RESULTS: The OR for the highest quartile group of waist circumference relative to the lowest was 2.39 (95% CI, 1.59-3.60; P-trend < 0.001). Comparing women with waist/hip ratio (WHR) in the lowest quartile group, the OR for women in the highest quartile category was 2.15 (95% CI, 1.61-2.85; P-trend < 0.001). An inverse association was observed between hip circumference and breast cancer, with an OR of 0.36 for the highest quartile (95% CI, 0.24-0.55; P-trend < 0.001). The effects of these three measures existed in both pre- and postmenopausal women. Of note, we found a significant interaction between WHR and BMI (P-interaction = 0.016): the OR comparing the highest to the lowest WHR quartile was 2.81 (95% CI, 1.90-4.16) for women with BMI < 25 kg/m2 and 1.70 (95% CI, 1.11-2.61) for women with BMI ≥ 25 kg/m2. CONCLUSIONS: These results suggest that central adiposity, measured by waist circumference and waist/hip ratio, was an important risk factor for breast cancer in Nigerian women, and the effect of central adiposity was strong in normal-weight women.

Case-control study of body size and breast cancer risk in Nigerian women.

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.