A matched case-control study of bean intake and breast cancer risk in urbanized Nigerian women.

PURPOSE: Bean intake has been associated with reduced risk of breast cancer, however; only a few studies considered molecular subtypes status and none in African women living in Sub-Saharan Africa (SSA). Therefore, the purpose of this study was to examine the associations between dietary intake of beans and breast cancer including its subtypes in Nigerian women. METHODS: Overall, 472 newly diagnosed patients with primary invasive breast cancer were age-matched (± 5 years) with 472 controls from the Nigerian Integrative Epidemiology of Breast Cancer (NIBBLE) Study from 01/2014 to 07/2016. We collected the dietary intake of beans using a food frequency questionnaire (FFQ). Beans_alone intake was categorized into three levels never (never in the past year), low (≤ 1 portion/week), and high intake (> 1 portion/week). We used conditional and unconditional logistic regression models to estimate the Odds Ratio (OR) and 95% Confidence Intervals (CI) of beans_alone intake and the risk of breast cancer and by its molecular subtypes, respectively. RESULTS: The mean (SD) age of cases was 44.4(10.0) and of controls was 43.5(9.5) years. In the case group, more than half (51.1%) have never consumed beans_alone in the past year compared to 39.0% in the control group. The multivariable models showed inverse associations between beans_alone (high vs. none) and breast cancer (OR = 0.55; 95%CI: 0.36-0.86, p-trend = 0.03), triple-negative (OR = 0.51 95%CI: 0.28-0.95, p-trend = 0.02) and marginally associated with hormone receptor-positive (OR = 0.53, 95%CI: 0.29-0.96, p-trend = 0.06). CONCLUSION: Dietary intake of beans_alone may play a significant role in reducing the incidence of breast cancer, particularly of the more aggressive molecular subtype, triple-negative, in African women living in SSA.

Prevalence of vaginal HPV infection among adolescent and early adult girls in Jos, North-Central Nigeria.

PURPOSE: Knowledge of the prevalence of HPV infection among adolescent and early adult girls is essential to determining the best age for the introduction of HPV vaccine, monitoring vaccine efficacy, and giving insight into determinants of persistent high-risk HPV infection, a necessary cause of cervical cancer. Yet, there have been limited studies of HPV infection among adolescent and early adult girls in low-and-middle-income countries. METHODS: In this cross-sectional study, we randomly selected 205 girls, aged 9-20 years, from 10 schools in central Nigeria. We obtained informed consent and assent, collected data, and trained participants to self-collect vaginal samples using swab stick. We genotyped HPV using SPF10-DEIA/LiPA25 and analyzed data using Stata 14®. RESULTS: The mean (SD) age of the girls was 14.9 (2.3) years. We found HPV in 13.2% of vaginal swabs. The earliest age at which anyHPV and hrHPV infections were detected was 10 and 12 years respectively. The prevalence of any HPV peaked at 16 and 17 years, hrHPV at 16 years, lrHPV at 17 and 18 years and multiple hrHPV 18 years of age. The prevalence of hrHPV infection was 1.5% among the 9-12 years age group, 2.9% among 13-16 years and 3.4% among 17-20 years old. The commonest hrHPV types detected were 52 (3.9%), 18 (1.5%) and 51 (2.4%). The most common lrHPV types was 6 (2.9%). CONCLUSION: The prevalence of HPV infection in these urbanized young girls in Nigeria is high and commences after 9 years of age. HPV vaccination in this population should start at 9 years of age or younger to prevent the establishment of persistent HPV infection.

Age-specific prevalence of human papilloma virus infection among Nigerian women.

BACKGROUND: Inconsistent trends in HPV prevalence by age have been described in Africa. We examined the age prevalence pattern and distribution of 37 HPV-DNA types among urban Nigerian women. METHODS: The study population was a sample of 278 women who presented to cervical cancer screening programs in Abuja, Nigeria, between April and August 2012. Using a nurse administered questionnaire, information on demographic characteristics and risk factors of cervical cancer was collected and samples of cervical exfoliated cells were obtained from all participants. Roche Linear Array HPV Genotyping Test® was used to characterize prevalent HPV and log-binomial regression models were used to examine the association between potential correlates and the prevalence of HPV infection. RESULTS: The mean age (SD) of the women enrolled was 38 (8) years. The overall prevalence of HPV was 37%. HPV 35 was the most prevalent HPV type in the study population. Among women age ≤ 30 years, 52% had HPV infection compared to 23% of those women who were older than 45 years (p = 0.006). We observed a significant linear association between age and the prevalence of HPV infections. The prevalence ratio (PR) and 95% confidence interval (CI) was 2.26 (1.17, 4.34) for any HPV infection, 3.83 (1.23, 11.94) for Group 1 HPV (definite carcinogens), and 2.19 (0.99, 4.84) for Group 2a or 2b HPV (probable or possible carcinogens) types, among women aged 18-30 years, compared to women who were older than 45 years. CONCLUSION: The prevalence of HPV infection was highest among younger women and decreased steadily with age among this population of urban Nigerian women.

Leisure-time physical activity is associated with reduced risks of breast cancer and triple negative breast cancer in Nigerian women.

BACKGROUND: Leisure-time physical activity(LTPA) is associated with a reduced risk of breast cancer, but this has less been investigated by cancer subtypes in Africans living in Sub-Saharan Africa(SSA). We examined the associations between LTPA and breast cancer including its subtypes in Nigerian women and explored the effect modification of body size on such associations. METHODS: The sample included 508 newly diagnosed primary invasive breast cancer cases and 892 controls from the Nigerian Integrative Epidemiology of Breast Cancer(NIBBLE) Study. Immunohistochemical(IHC) analysis was available for 294 cases. Total metabolic equivalents(METs) per hour/week of LTPA were calculated and divided by quartiles(Q1 <3.75, Q2:3.75-6.69, Q3:6.70-14.74, Q4:14.75 ≤). We applied logistic regressions to estimate the adjusted Odds Ratios(ORs) between LTPA and breast cancer and by its molecular subtypes and whether age-adjusted associations are modified by BMI. RESULTS: The mean age(Mean±SD) of cases vs. controls(45.5 ± 11.1vs.40.1 ± 9.0) was higher, and the mean total METs hour/week was higher in controls vs. cases(11.9 ± 14.9vs.8.3 ± 11.1,p-value<0.001). Overall, 43.2%(N = 127/294) were classified as HRP, and 41.8%(N = 123/294) as TNBC. Women in the higher LTPA quartiles(Q3-Q4) vs. Q1 had lower odds of having breast cancer(ORQ4vs.Q1=0.51,95%CI:0.35-0.74) and TNBC(ORQ4vs.Q1=0.51, 95%CI:0.27-0.96), but not HRP(ORQ4vs.Q1=0.61,95%CI:0.34-1.09) after adjusting for age, age at first menarche, body size, breastfeeding, menopausal, parity, contraceptives, demographics, alcohol, smoking, and physical activity at home and work. Lastly, LTPA and its age-adjusted association with breast cancer was more pronounced in women with BMI< 30 vs. BMI 30 + . CONCLUSIONS: LTPA may reduce the risk of breast cancer, especially TNBC, which is the more aggressive and prevalent molecular subtype of breast cancer in SSA.

RPS19 and TYMS SNPs and Prevalent High Risk Human Papilloma Virus Infection in Nigerian Women.

High risk HPV (hrHPV) infection is a necessary cause of cervical cancer but the host genetic determinants of infection are poorly understood. We enrolled 267 women who presented to our cervical cancer screening program in Abuja, Nigeria between April 2012 and August 2012. We collected information on demographic characteristics, risk factors of cervical cancer and obtained samples of blood and cervical exfoliated cells from all participants. We used Roche Linear Array HPV Genotyping Test® to characterize the prevalent HPV according to manufacturer's instruction; Sequenom Mass Array to test 21 SNPs in genes/regions previously associated with hrHPV and regression models to examine independent factors associated with HPV infection. We considered a p<0.05 as significant because this is a replication study. There were 65 women with and 202 women without hrHPV infection. Under the allelic model, we found significant association between two SNPs, rs2305809 on RPS19 and rs2342700 on TYMS, and prevalent hrHPV infection. Multivariate analysis of hrHPV risk adjusted for age, body mass index, smoking, age of menarche, age at sexual debut, lifetime total number of sexual partners and the total number of pregnancies as covariates, yielded a p-value of 0.071 and 0.010 for rs2305809 and rs2342700, respectively. Our findings in this unique population suggest that a number of genetic risk variants for hrHPV are shared with other population groups. Definitive studies with larger sample sizes and using genome wide approaches are needed to understand the genetic architecture of hrHPV risk in multiple populations.