Breast Cancer In Nigerian Women Research Articles

Abstract PO4-09-02: Making a Case for Access to Genetic Testing in a Low Resource Country: A review of 313 Cases of MBC

Abstract Background Breast Cancer is the most common malignancy in Nigerian Women. It is responsible for the highest mortality amongst all malignant conditions. Breast cancer in Nigerian women typically presents at an earlier age and with a more aggressive tumour with triple negative molecular pattern in Nigerian women. These are usually some of the criteria for Genetic testing in the NCCN Guidelines. Due to resource challenges, Genetic testing is not readily available to Nigerian women We believe that if we can demonstrate that a high proportion of Nigerian women with breast cancer meet the criteria for Genetic Testing for Hereditary Breast and Ovarian Cancers, a case can be made for deploying resources towards Genetic Testing in this population of Women. Materials and Methods We collected prospective data about Nigerian Patients with Metastatic Breast Cancer as part of a UICC MBC Grant. We evaluated these patients for criteria for testing for breast cancer and present the result of our evaluation. Results Three hundred and Thirteen patients were recruited for this study. There were 2 male and 311 female. Twelve participants did not know their age, but 146 (40.3%) were younger than 45 years while 175 (55.9%) were older than 45 years. Twenty four (7.7%) had bilateral breast cancer while the 289 (92.3%) had unilateral breast cancer. One hundred and sixty two (54.8%) participants were triple negative, 124 of whom were 60 years or younger. In total, out of 313 participants, 202 (64.5%) patients were candidates for Genetic testing in a cohort of Metastatic Breast Cancer patients in Nigeria. Conclusion Various Indications for Genetic Testing in a cohort of Nigerian patients with breast cancer exists in more than 60% of patients. Considering the importance of PARP inhibitors in the management of breast cancer and implications for family members of these patients. It is important that cost appropriate genetic testing is made available to this group of breast cancer patients. Table. Risk Factors for Genetic Testing in Nigerian Patients Citation Format: Adewumi Alabi, AbdulRazzak Lawal, Tolulope Falowo, Olamijulo Fatiregun. Making a Case for Access to Genetic Testing in a Low Resource Country: A review of 313 Cases of MBC [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-09-02.

Barriers to Early Presentation and Diagnosis of Breast Cancer in Nigerian Women

Barriers to Early Presentation and Diagnosis of Breast Cancer in Nigerian Women

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

BackgroundLeisure-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. MethodsThe 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. ResultsThe 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 + . ConclusionsLTPA may reduce the risk of breast cancer, especially TNBC, which is the more aggressive and prevalent molecular subtype of breast cancer in SSA.

Association of body composition with odds of breast cancer by molecular subtype: analysis of the Mechanisms for Established and Novel Risk Factors for Breast Cancer in Nigerian Women (MEND) study

BackgroundThe association between obesity and breast cancer (BC) has been extensively studied among US, European and Asian study populations, with often conflicting evidence. However, despite the increasing prevalence of obesity and associated conditions in Africa, the continent with the highest age-standardized BC mortality rate globally, few studies have evaluated this association, and none has examined in relation to molecular subtypes among African women. The current analysis examines the association between body composition, defined by body mass index (BMI), height, and weight, and BC by molecular subtype among African women.MethodsWe estimated odds ratios (ORs) and 95% confidence intervals (95% CI) for the association between measures of body composition and BC and molecular subtypes among 419 histologically confirmed cases of BC and 286 healthy controls from the Mechanisms for Established and Novel Risk Factors for Breast Cancer in Women of Nigerian Descent (MEND) case-control study.ResultsHigher BMI (aOR: 0.79; 95% CI: 0.67, 0.95) and weight (aOR: 0.83; 95% CI: 0.69, 0.98) were associated with reduced odds of BC in adjusted models, while height was associated with non-statistically significant increased odds of BC (aOR: 1.07, 95% CI: 0.90, 1.28). In pre/peri-menopausal, but not post-menopausal women, both higher BMI and weight were significantly associated with reduced odds of BC. Further, higher BMI was associated with reduced odds of Luminal A, Luminal B, and HER2-enriched BC among pre/peri-menopausal women, and reduced odds of triple-negative BC among post-menopausal women.ConclusionsHigher BMI and weight were associated with reduced odds of BC overall and by molecular subtype among West African women. Larger studies of women of African descent are needed to definitively characterize these associations and inform cancer prevention strategies.

Association of Life-Course Educational Attainment and Breast Cancer Grade in the MEND Study.

Background:Nigeria reports the highest age-standardized mortality rate for breast cancer (BC) among African countries and disproportionately high rates of high-grade cancer. Histological grade is a strong predictor of mortality, and evidence suggests that educational attainment influences cancer outcomes.Objective:We characterize the association between educational trends across the life-course and BC grade at diagnosis.Methods:Data on 224 BC patients enrolled in the Mechanisms for Established and Novel Risk Factors for Breast Cancer in Nigerian Women (MEND) study was analyzed. Participant and parental (mother and father) education was categorized as low (primary school or less) or high (secondary school or greater). Accordingly, the educational trend across the life-course was determined for each participant relative to each parent: stable high, increasing, decreasing, or stable low. BC grade was classified as high (grade 3) or low (grades 1–2).Findings:About 34% of participants, 71% of fathers, and 85% of mothers had low education. Approximately one-third of participants were diagnosed with high-grade BC. Participants with low-grade BC were more likely to have highly educated fathers (p = 0.04). After adjusting for age, comorbidities, marital status and mammogram screening, participants with highly educated fathers were 60% less likely to have high-grade BC (aOR 0.41; 95% CI 0.20 to 0.84) compared to those with less-educated fathers. Stable high life-course education relative to father was also associated with a significantly lower likelihood of having high-grade BC (aOR 0.36; 95% CI 0.15 to 0.87) compared to stable low life-course education. No significant associations were observed for the participant’s education, mother’s education, or life-course education relative to mother.Conclusions:Early-life socioeconomic status (SES) may influence BC grade. This deserves further study to inform policies that may be useful in reducing high-grade BC in Nigeria.

Factors influencing the health-seeking behaviors of women with advanced stages of breast cancer in Southwestern Nigeria: An interpretive description study

BackgroundThe World Health Organization (WHO) indicates the survival rate from breast cancer in Nigerian women is 48.9%. Little is known about the health-seeking behaviors and the factors that influence women with advanced breast cancer in Southwestern Nigeria to seek care. ObjectivesThis paper presents the factors influencing the health-seeking activities of women with advanced breast cancer from the time the participants observed breast changes until they presented in the hospital for care. MethodsQualitative methods, specifically Interpretive Description (ID), was employed within the conceptual framework of the Health Belief Model (HBM). A University Human Ethics Review Board (REB) approved the study, while operational approval was granted by the hospital where the data collection took place. Thirty women with advanced breast cancer were recruited for the study using purposive sampling. Data was collected by engaging the participants in audio-recorded, semi-structured, face-to-face, one-on-one interviews guided by open-ended questions and a demographic form. The interview transcripts were analyzed using thematic analysis, while the demographic information was analyzed using descriptive statistics. ResultsThe study identified motivating and enabling factors as well as barriers to engaging in health-seeking behaviors. Breast changes, interpretation of symptoms, the financial challenges of breast cancer treatments, sociocultural factors, and a desire to live influenced the participants’ health-seeking behaviors. ConclusionKnowledge of these factors may help nurses and other healthcare providers to consider their patients’ health beliefs and perceptions, thereby empowering nurses to provide comprehensive, holistic, contextually relevant and efficient care to their patients. Community interventions should include strategies to raise breast cancer awareness and reduce the stigma associated with the illness.

Abstract 5468: Gene fusions in breast cancer in Nigerian women

Abstract Background: As a chromosomal rearrangement event, gene fusion plays a critical role in the pathogenesis of cancer by creating potentially oncogenic chimeric proteins. However, gene fusions have been understudied in breast cancer patients of African ancestry, who are often diagnosed at a younger age and with more aggressive molecular features of cancer than patients of other races/ethnicities. Methods: Ninety-six women diagnosed with invasive breast cancer were recruited from Ibadan, Nigeria with mean age at diagnosis of 51.6 ± 12.4 years. Primary tumors were collected, of which 62 (64.6%) were hormone receptor negative (HR-) by immunohistochemistry, and 31 (32.3%) were basal-like subtype by PAM50 classification. Paired-end reads from RNA-seq on these tumors were used for gene fusion detection by three programs, STAR-Fusion, STAR-SEQR, and Arriba. To increase specificity, we applied an ensembling method by selecting fusions identified by at least two of the three callers. Multiple filters were applied to fusion candidates to remove likely false positives, including fusions containing genes of mitochondrial origin, fusions consisting of pairs of paralogues or orthologs, fusions involving HLA genes, and fusions found in several databases of non-cancer tissues. To investigate potentially druggable fusion transcripts, we compared our call set with the OncoKB precision oncology knowledge base. Results: STAR-Fusion, STAR-SEQR, and Arriba identified 682, 4529, and 3056 unique fusion transcripts, respectively. Following application of the ensembling method and filtering to select final fusions, 709 unique fusions were identified. Comparison with 13 databases and published papers identified 62 of these fusions as previously reported. The mean fusion burden per sample was 7.7 ± 7.4. The fusion burden per sample was significantly smaller for tumors classified as Luminal A subtypes by PAM50 classification than Luminal B, Basal, and HER2 subtypes (P &amp;lt; 0.03) as well as normal like (P &amp;lt; 0.01). Fusion burden was highest in HER2 tumors (NS), consistent with previous reports. The number of fusion transcripts per sample did not differ significantly according to the patient's age. Ninety-six percent of fusion transcripts were only identified in a single sample, including the ETV6-NTRK3 fusion, previously reported in secretory breast carcinoma, and BCR-ABL1, both of which are targeted by a drug identified in OncoKB. The most commonly observed fusion, EDDM13–ZNF71, appeared in 4.2% (4/96) of samples. Conclusion: The vast majority of breast cancer samples from Nigerian women demonstrate unique fusion transcripts in expressed RNA. Fusion burden per sample was related to PAM50 classification. Future work will incorporate functional studies of the recurrent gene fusion events identified in our cohort. We will additionally focus on validation and refinement of our approach to detecting gene fusions in this understudied population, in order to better identify patients who can benefit from new therapies. Citation Format: Anna Elizabeth Woodard, Toshio F. Yoshimatsu, WABCS Working Group, Jason J. Pitt, Yonglan Zheng, Olufunmilayo I. Olopade. Gene fusions in breast cancer in Nigerian women [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5468.

Matched Case-Control Study of Beans Intakes and Breast Cancer Risk in Urbanized Nigerian Women

Abstract Objectives To examine the association between dietary intake of beans and breast cancer in Nigerian women. Methods Overall 630 newly diagnosed patients with primary invasive breast cancer were age-matched (±5 years) with 630 controls from the Nigerian Integrative Epidemiology of Breast Cancer (NIBBLE) Study from 01/2014 to 07/2016. Dietary intakes were collected using a food frequency questionnaire (FFQ) to derive daily intake of beans. The daily bean intakes included intakes of beans alone, bean porridge, bean cake (akara), bean pudding (moinmoin), beans and corn (adalu) and bean soup (gbegiri). We categorized the daily bean intake into low, medium and high equally based on the distribution. Additional covariates included occupation, education, wealth index, contraceptive use, menopause status, number of pregnancies, breastfeeding, Body Mass Index, Waist to Hip Ratio and physical activity. Conditional logistic regression models were utilized to estimate the crude and adjusted Odds Ratio (OR) of total beans intake per day and breast cancer. Results The mean (SD) age of the cases was 42.5 (10.1) and controls was 41.5 (9.2) years. Among controls, almost 36% consume a high intake of total bean compared to 30% among cases, whereas among the cases 37.3% consumed the low intake of total bean compared to 31.6% among controls. In the multivariable, we found a significant association between total beans intakes and breast cancer (OR = 0.85; 95% CI: 0.74–0.97, p-value = 0.02). Comparing the highest category (approximately two portions or more a day) with the lowest category (less than one portion a day), the adjusted OR was 0.72 (95% CI: 0.52–0.98, p-value for trend = 0.04). Conclusions We found a significant association between high intakes of beans and reduce risks for breast cancer. Future studies are needed to evaluate the causality of this relationship and the specific component of beans that is responsible for this reduction. Funding Sources National Human Genome Research Institute of the National Institutes of Health's African Collaborative Center for Microbiome and Genomics Research grant, Award Number U54HG006947; the Fogarty International Center of the National Institutes of Health's Training Program in Nigeria for Non-communicable Diseases Research (TRAPING NCD), Award Number D43TW009106, the Maryland Department of Health's Cigarette Restitution Fund Program.

Anthropometric variables in relation to risk of breast cancer in Nigerian women

Anthropometric variables in relation to risk of breast cancer in Nigerian women

Abstract LB-300: The life history of breast cancer in Nigerian women: Evidence for ethnic differences in tumor evolution based on whole-genome sequencing

Abstract Breast cancer is a heterogeneous disease and the incidence to mortality ratio is highest for women of African ancestry. Paucity of data from non-European ancestry groups limits our understanding of the underlying etiological differences or alternative routes to progression that may explain differential outcomes. To examine the contribution of genomic differences, we performed high-depth whole-genome sequencing on 100 breast tumors (90X) and their paired normal samples (30X) from indigenous African women with breast cancer in Southwest Nigeria and performed comparative analysis with 84 TCGA whole genome sequences of breast tumor/normal pairs (46 White, 30 African American and 8 samples representing other ethnicities). High confidence somatic single nucleotide variants (SNVs) were obtained by using MuTect and Strelka. To analyse intra-tumoral heterogeneity (ITH), Battenberg and DPClust were used to call copy number aberrations (CNA) and cluster somatic SNVs based on cancer cell fraction (CCF) respectively. We find that in the HR-/HER2+ subtype, clonal losses of chromosome 14q are highly enriched in Nigerians (41%) but absent in the Whites even though the proportion of this subtype was comparable between the two groups (42% and 33% respectively). This is an interesting observation since not only 14q loss is known to be an event associated with breast cancer aggressiveness, but HR-/HER2+ has also been reported to be enriched within the relatively younger Nigerian patients with breast cancer. This may in part explain inter-ethnic disparity in survival. Also, somatic SNV clustering analysis showed that Nigerian cancers have a higher level of ITH than Whites, which may explain the pronounced aggressiveness of breast cancer in women of African ancestry. In contrast, early drivers (e.g. TP53 and PIK3CA) and whole genome duplication rates were mostly similar between the groups. Our observations suggest differences in the underlying evolutionary trajectories of breast cancer across ethnic backgrounds. These data underscore the need for larger and more in-depth studies of diverse cancer genomes and, if validated, may translate into clinical intervention opportunities tailored to women of African ancestry and accelerate progress in precision cancer care. Note: This abstract was not presented at the meeting. Citation Format: Naser Ansari-Pour, Jason J. Pitt, Stefan Dentro, Dominic Fitzgerald, Yonglan Zheng, Toshio F. Yoshimatsu, Padma Rajagopal, Andreas Gruber, Ayodele Sanni, Olayiwola Oluwasola, Mustapha Ajani, Abayomi Odetunde, Abiodun Popoola, Adeyinka Falusi, Temidayo Ogundiran, John Obafunwa, Oladosu Ojengbede, Nasiru Ibrahim, Kevin P. White, Dezheng Huo, Peter Van Loo, David C. Wedge, Olufunmilayo Olopade. The life history of breast cancer in Nigerian women: Evidence for ethnic differences in tumor evolution based on whole-genome sequencing [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr LB-300.

Practice and Barriers of Breast Self-Examination Among Women in a Rural Community in South Western, Nigeria

Background: Breast cancer (BC) is the most common cancer and the second cause of cancer deaths in women worldwide as well as in Nigeria .The incidence of the disease appears to be rising faster in a population groups which had hitherto enjoyed low incidence, with the peak age of breast cancer in Nigerian women being about ten years earlier than CaucasiansAim: This study investigated the practice of BSE and its possible barriers among women in a rural community in South Western area of Oyo State; Nigeria.Study design: The study utilized Participatory Action Research (PAR) design using purposive and cross sectional sampling technique for survey and 95 women for the focus group discussion. The PAR framework involves four phases: Observe, Reflect, Plan and Act. Structured questionnaire was used for phase one, and A - 3 session FGD was used for phases on Reflect and Plan. Data was analyzed using the SPSS version 21, while content analysis for FGD to identify common themes.Results: The study reveals that 75.1% had no knowledge of breast self-examination at all while only 24.9% had knowledge of what BSE, their sources of information was majorly health Professionals ( 47.5%), electronic media (21.4%), . 76.5%) did not practice BSE. Also, about 77% of the respondents expressed one form of barrier or another to BSE practice. Major barriers to the practice of BSE identified are revealed based on these themes: - ‘knowledge/awareness of BSE’, ‘practice and appeal for intervention’, and ‘misconceptions and fear of being diagnosed’.Conclusion: More than half of the participants do not practiced BSE. Some socio demographic significantly influenced the practice of the BSE. Lack of knowledge, not having any symptoms, myths and being afraid of being diagnosed with breast cancer were the main barriers to practicing BSE. There is need to develop a continuous awareness campaign among rural women on the importance of performing BSE.

Leisure Time Physical Activity Is Associated with Substantial Reduction in Risk of Breast Cancer and Breast Cancer Subtypes in Nigerian Women (P16-007-19)

Abstract Objectives To examine the association between leisure-time physical activity (LTPA) and breast cancer in Nigerian women. The hypothesis was that LTPA decreased breast cancer cases in Nigerian women. To examine the association between LTPA and estrogen receptor positive (ER+), triple negative breast cancer (TNBC+), Luminal A breast cancer in Nigerian women. The hypothesis was that LTPA decreased breast cancer subtypes in Nigerian women. Methods We enrolled 739 newly diagnosed primary invasive breast cancer and 739 age-matched controls in Nigeria from 01/2014 to 07/2016. This analysis is restricted to the 40% of cases for whom we have complete ER, TNBC, and Luminal-A data and their matched controls. We derived the average amount of time per week spent on LTPA over the past year using a modified Nurses’ Health Study II PA questionnaire. LTPA was calculated from the total metabolic equivalent (METs) assigned for each reported physical activity hour/week (i.e., walking, cycling, and dancing). We examined LTPA by comparing participants who attained the WHO physical activity recommendations of at least 150 minutes of moderate-intensity or/and 75 minutes of vigorous-intensity aerobic activity weekly with those who did not. We used conditional logistic regression to estimate the adjusted Odds Ratio (OR) of LTPA and overall as well as subtypes of breast cancer. Results The mean (SD) age of cases was 41.6 (9.1) and controls 43.9 (11.8) years. Women who attained the WHO physical activity recommendations had 43% decreased the risk of breast cancer (OR = 0.57, 95% CI:0.42–0.77) compared with those who did not, after controlling for demographic, anthropometric and fertility-related factors. LTPA was also associated with reduced risk of breast cancer subtypes by 41% for ER+, 59% for TNBC+and 59% for Luminal A. Conclusions Physical activity is associated with reduced risk of breast cancer overall and by subtypes in Nigerian women. Funding Sources Training Program in Nigeria for Non-Communicable Diseases Research (TRAPING NCD) grant number FIC/NIH D43TW009106 from the Fogarty International Centre. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Fogarty International Centre or the National Institutes of Health.

Association of leisure time physical activity with breast cancer risk and breast cancer sub-types in Nigerian women.

e13085 Background: The association between physical activity and breast cancer has not been studied among Nigerian women and in particular by breast cancer sub-types. Therefore are studies aims are to examine the association between leisure time physical activity (LTPA) and breast cancer in Nigerian women and to examine the association between LTPA and estrogen receptor positive (ER+), triple negative breast cancer (TNBC+), Luminal A breast cancer in Nigerian women. Methods: We enrolled 739 newly diagnosed primary invasive breast cancer and 739 age-matched controls in Nigeria from 01/2014 to 07/2016. This analysis is restricted to the 40% of cases for whom we have complete ER, TNBC and Luminal-A data and their matched controls. We derived the average amount of time per week spent on LTPA over the past one year using a modified Nurses’ Health Study II PA questionnaire. LTPA was calculated from the total metabolic equivalent (METs) assigned for each reported physical activity hour/week (i.e. walking, cycling, and dancing). We examined LTPA by comparing participants who attained the WHO physical activity recommendations of at least 150 minutes of moderate-intensity or/and 75 minutes of vigorous-intensity aerobic activity weekly with those who did not. We used conditional logistic regression to estimate the adjusted Odds Ratio (OR) of LTPA and overall as well as subtypes of breast cancer. Results: The mean (SD) age of cases was 41.6 (9.1) and controls was 43.9 (11.8) years. Women who attained the WHO physical activity recommendations had 43% decreased risk of breast cancer (OR = 0.57 95% CI:0.42-0.77) compared with those who did not, after controlling for demographic, anthropometric and fertility related factors. LTPA was also associated with reduced risk of breast cancer subtypes by 41% for ER+, 59% for TNBC+ and 59% for Luminal A. Conclusions: Physical activity is associated with reduced risk of breast cancer overall and by subtypes in Nigerian women.

Inherited Breast Cancer in Nigerian Women.

PurposeAmong Nigerian women, breast cancer is diagnosed at later stages, is more frequently triple-negative disease, and is far more frequently fatal than in Europe or the United States. We evaluated the contribution of an inherited predisposition to breast cancer in this population.Patients and MethodsCases were 1,136 women with invasive breast cancer (mean age at diagnosis, 47.5 ± 11.5 years) ascertained in Ibadan, Nigeria. Patients were selected regardless of age at diagnosis, family history, or prior genetic testing. Controls were 997 women without cancer (mean age at interview, 47.0 ± 12.4 years) from the same communities. BROCA panel sequencing was used to identify loss-of-function mutations in known and candidate breast cancer genes.ResultsOf 577 patients with information on tumor stage, 86.1% (497) were diagnosed at stage III (241) or IV (256). Of 290 patients with information on tumor hormone receptor status and human epidermal growth factor receptor 2, 45.9% (133) had triple-negative breast cancer. Among all cases, 14.7% (167 of 1,136) carried a loss-of-function mutation in a breast cancer gene: 7.0% in BRCA1, 4.1% in BRCA2, 1.0% in PALB2, 0.4% in TP53, and 2.1% in any of 10 other genes. Odds ratios were 23.4 (95% CI, 7.4 to 73.9) for BRCA1 and 10.3 (95% CI, 3.7 to 28.5) for BRCA2. Risks were also significantly associated with PALB2 (11 cases, zero controls; P = .002) and TP53 (five cases, zero controls; P = .036). Compared with other patients, BRCA1 mutation carriers were younger (P < .001) and more likely to have triple-negative breast cancer (P = .028).ConclusionAmong Nigerian women, one in eight cases of invasive breast cancer is a result of inherited mutations in BRCA1, BRCA2, PALB2, or TP53, and breast cancer risks associated with these genes are extremely high. Given limited resources, prevention and early detection services should be especially focused on these highest-risk women.

Breast Cancer in Nigerian Women: Evaluating the Utility of Circulating Immune Complexes and Cancer Antigens (CA 15-3 and CA 27.29) in Disease Surveillance

Breast Cancer in Nigerian Women: Evaluating the Utility of Circulating Immune Complexes and Cancer Antigens (CA 15-3 and CA 27.29) in Disease Surveillance

Determinants of stage at diagnosis of breast cancer in Nigerian women: sociodemographic, breast cancer awareness, health care access and clinical factors.

Advanced stage at diagnosis is a common feature of breast cancer in Sub-Saharan Africa (SSA), contributing to poor survival rates. Understanding its determinants is key to preventing deaths from this cancer in SSA. Within the Nigerian Integrative Epidemiology of Breast Cancer Study, a multicentred case-control study on breast cancer, we studied factors affecting stage at diagnosis of cases, i.e. women diagnosed with histologically confirmed invasive breast cancer between January 2014 and July 2016 at six secondary and tertiary hospitals in Nigeria. Stage was assessed using clinical and imaging methods. Ordinal logistic regression was used to examine associations of sociodemographic, breast cancer awareness, health care access and clinical factors with odds of later stage (I, II, III or IV) at diagnosis. A total of 316 women were included, with a mean age (SD) of 45.4 (11.4) years. Of these, 94.9% had stage information: 5 (1.7%), 92 (30.7%), 157 (52.4%) and 46 (15.3%) were diagnosed at stages I, II, III and IV, respectively. In multivariate analyses, lower educational level (odds ratio (OR) 2.35, 95% confidence interval: 1.04, 5.29), not believing in a cure for breast cancer (1.81: 1.09, 3.01), and living in a rural area (2.18: 1.05, 4.51) were strongly associated with later stage, whilst age at diagnosis, tumour grade and oestrogen receptor status were not. Being Muslim (vs. Christian) was associated with lower odds of later stage disease (0.46: 0.22, 0.94). Our findings suggest that factors that are amenable to intervention concerning breast cancer awareness and health care access, rather than intrinsic tumour characteristics, are the strongest determinants of stage at diagnosis in Nigerian women.

BREAST CANCER RISK PREDICTION USING DATA MINING CLASSIFICATION TECHNIQUES

Breast cancer poses serious threat to the lives of people and it is the second leading cause of death in women today and the most common cancer in women in developing countries in Nigeria where there are no services in place to aid the early detection of breast cancer in Nigerian women. A number of studies have been undertaken in order to understand the prediction of breast cancer risks using data mining techniques. Hence, this study is focused at using two data mining techniques to predict breast cancer risks in Nigerian patients using the naive bayes’ and the J48 decision trees algorithms. The performance of both classification techniques was evaluated in order to determine the most efficient and effective model. The J48 decision trees showed a higher accuracy with lower error rates compared to that of the naive bayes’ method while the evaluation criteria proved the J48 decision trees to be a more effective and efficient classification techniques for the prediction of breast cancer risks among patients of the study location.

Risk factors for pregnancy-associated breast cancer: a report from the Nigerian Breast Cancer Study

PurposeLittle is known about risk factors for pregnancy-associated breast cancer (PABC), diagnosed during pregnancy or postpartum. MethodsWe enrolled 1715 premenopausal women from the Nigerian Breast Cancer Study from 1998 to 2011. Based on recency of last pregnancy from diagnosis, breast cancer cases were categorized as (1) PABC diagnosed 2 years or longer postpartum, (2) PABC diagnosed 3 to 5 years postpartum, or (3) non-PABC diagnosed more than 5 years postpartum. Controls were matched to cases on recency of last pregnancy. Multiple logistic regressions were performed comparing cases and controls within each group. ResultsOf the 718 cases, 152 (21.2%) had PABC 2 or more years postpartum, and 145 (20.2%) 3 to 5 years postpartum. Although not statistically significant, women with higher parity tend to have an elevated risk of PABC but reduced risk of non-PABC (p for heterogeneity = 0.097). Family history of breast cancer might be a strong predictor particularly for PABC 2 or more years postpartum (odds ratio, 3.28; 95% confidence interval, 1.05–10.3). Compared with non-PABC cases, PABC 2 or more years postpartum cases were more likely to carry BRCA1/2 mutations (P = .03). ConclusionsParity may have different roles in the development of PABC versus other premenopausal breast cancer in Nigerian women. Prospective mothers with multiple births and a family history of breast cancer may have an elevated risk of breast cancer during their immediate postpartum period.

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

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. 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. 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. 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.

Biology of breast cancer in Nigerian women: A pilot study

Compared to the developed world, there are relatively few studies that describe the tumor biology of breast cancer in African women. While little is known about the tumor biology, clinical and epidemiologic studies suggest that breast cancer in African women are characterized by presentation at late stage and poor clinical outcomes. Analysis of the biological features of breast cancers in Nigerian women was designed to bring additional insight to better understand the spectrum of disease, the phenotypes that present, and the types of interventions that might improve outcomes. We performed histological analyses for hormone receptors (estrogen and progesterone receptors), HER2, and tumor infiltrating macrophages (TAM) on 17 breast cancers, obtained from Abia State University Teaching Hospital (Aba, Nigeria), between November 2008 and October 2009. On a subset of these cases, we investigated the potential role of a virus in the etiology of these aggressive cancers. The majority of cases in this cohort were characterized as high grade (100% were grade III), triple-negative (65%), and occur in young women (mean age 47 years). We observed high infiltration of TAMs in these tumors, but no evidence of a viral etiology. Our findings indicate that breast cancers in Nigerian women have a highly aggressive phenotype (high grade, hormone receptor negative), which is similar to other studies from Africa and other developing nations, as well as from African American women, but is significantly different from Caucasian women in the developed world. The presence of high numbers of TAMs in these tumors raises the possibility of targeting the immune microenvironment for therapeutic interventions.