Abstract
Purpose
There are no published data from specific regions of sub-Saharan Africa describing the clinical and pathological characteristics and molecular subtypes of invasive breast cancer by ethnic group. The purpose of this study was to investigate these characteristics among the three major ethno-cultural groupings in Kenya.
Methods
The study included women with pathologically confirmed breast cancer diagnosed between March 2012 and May 2015 at 11 hospitals throughout Kenya. Sociodemographic, clinical, and reproductive data were collected by questionnaire, and pathology review and immunohistochemistry were performed centrally.
Results
The 846 cases included 661 Bantus (78.1%), 143 Nilotes (16.9%), 19 Cushites (2.3%), and 23 patients of mixed ethnicity (2.7%). In analyses comparing the two major ethnic groups, Bantus were more educated, more overweight, had an older age at first birth, and had a younger age at menopause than Nilotes (p < 0.05 for all comparisons). In analyses restricted to definitive surgery specimens, there were no statistically significant differences in tumor characteristics or molecular subtypes by ethnicity, although the Nilote tumors tended to be larger (OR for ≥ 5 cm vs. < 2 cm: 3.86, 95% CI 0.77, 19.30) and were somewhat more likely to be HER2 enriched (OR for HER2 enriched vs. Luminal A/B: 1.41, 95% CI 0.79, 2.49).
Conclusion
This case series showed no significant differences in breast cancer tumor characteristics or molecular subtypes, but significant differences in sociodemographic characteristics and reproductive factors, among the three major ethnic groups in Kenya. We suggest further evaluation of ethnic differences in breast cancer throughout the genetically and culturally diverse populations of sub-Saharan Africa.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulen J, Jemal A (2015) Global cancer statistics, 2012. CA Cancer J Clin 65(2):87–108
Korir A, Okerosi N, Ronoh V, Mutuma G, Parkin M (2015) Incidence of cancer in Nairobi, Kenya (2004–2008). Int J Cancer 2059(137):2053–2059
Bhikoo R, Srinivasa S, Yu TC, Moss D, Hill AG (2011) Systematic review of breast cancer biology in developing countries (part 1): Africa, the Middle East, Eastern Europe, Mexico, the Caribbean and South America. Cancers (Basel) 3(2):2358–2381
Porter PL, Lund MJ, Lin MG, Yuan X, Liff JM, Flagg EW et al (2004) Racial differences in the expression of cell cycle-regulatory proteins in breast carcinoma. Cancer 100(12):2533–2542
Der EM, Gyasi RK, Tetty Y, Edusei L, Bayor MTJM, Gyakobo M, LA Merajver SDN (2015) Triple negative breast cancer in Ghanaian Women: The Korle Bu Teaching Hospital experience. Breast J 21(6):627–633
Hahn KME, Bondy ML, Selvan M, Lund MJ, Liff JM, Flagg EW et al (2007) Factors associated with advanced disease stage at diagnosis in a population-based study of patients with newly diagnosed breast cancer. Am J Epidemiol 166(9):1035–1044
Middleton LP, Chen V, Perkins GH, Pinn V, Page D (2003) Histopathology of breast cancer among African-American women. Cancer 97(1 Suppl):253–257
Dickens C, Pfeiffer RM, Anderson WF, Duarte R, Kellett P, Schüz J et al (2016) Investigation of breast cancer sub-populations in black and white women in South Africa. Breast Cancer Res Treat [Internet] 160(3):531–537
Ethnic Groups of Kenya - SourceWatch (2017). http://www.sourcewatch.org/index.php/Ethnic_Groups_of_Kenya
Sayed S, Moloo Z, Wasike R, Bird P, Oigara R, Govender D et al (2014) Is breast cancer from Sub Saharan Africa truly receptor poor? Prevalence of ER/PR/HER2 in breast cancer from Kenya. The Breast 23(5):591–596
Mahdi Tazhibi, Feizi A (2014) Awareness levels about breast cancer risk factors, early warning signs, and screening and therapeutic approaches among Iranian adult women: a large population-based study using latent class analysis. Biomed Res Int. doi:10.1155/2014/306352
Sayed Shahin, Moloo Zahir, Ngugi Anthony, Allidina Amyn, Ndumia Rose, Mutuiri Anderson et al (2016) Breast camps for awareness and early diagnosis of breast cancer in countries with limited resources: a multidisciplinary model from Kenya. Oncologist 21:1138–1148
Awadelkarim KD, Arizzi C, Elamin EOM, Hamad HMA, De Blasio P, Mekki SO et al (2008) Pathological, clinical and prognostic characteristics of breast cancer in Central Sudan versus Northern Italy: implications for breast cancer in Africa. Histopathology 52(4):445–456
Miller BA, Hankey BF, Thomas TL (2002) Impact of sociodemographic factors, hormone receptor status, and tumor grade on ethnic differences in tumor stage and size for breast cancer in US women. Am J Epidemiol 155(6):534–545
Kakarala M, Rozek L, Cote M, Liyanage S, Brenner DE (2010) Breast cancer histology and receptor status characterization in Asian Indian and Pakistani women in the U.S.–a SEER analysis. BMC Cancer 10:191
Li CI, Malone KE, Daling JR (2002) Differences in breast cancer hormone receptor status and histology by race and ethnicity among women 50 years of age and older. Cancer Epidemiol Prev Biomark 11(7):601–607
Jemal A, Fedewa S (2012) Is the prevalence of ER-negative breast cancer in the US higher among Africa-born than US-born black women? Breast Cancer Res Treat 135(3):867–873
Bird PA, Hill AG, Houssami N (2008) Poor hormone receptor expression in East African breast cancer: evidence of a biologically different disease? Ann Surg Oncol 15(7):1983–1988
Pasquet P, Maguelle-Dicoum Biyong A, Rikong-Adie H et al (1999) Age at menarche and urbanization in Cameroon: current status and secular trends. Ann Hum Biol 26(1):89–97
Henderson KD, Bernstein L, Henderson B, Kolonel L, Pike MC (2008) Predictors of the timing of natural menopause in the multiethnic cohort study. Am J Epidemiol 167(11):1287–1294
Elks CE, Perry JRB, Sulem P, Chasman DI, Franceschini N, He C et al (2010) Thirty new loci for age at menarche identified by a meta-analysis of genome-wide association studies. Nat Genet 42(12):1077–1085. http://www.ncbi.nlm.nih.gov/pubmed/21102462
Stolk L, Perry JRB, Chasman DI, He C, Mangino M, Sulem P, et al (2012) Meta-analyses identify 13 loci associated with age at menopause and highlight DNA repair and immune pathways. Nat Genet 44(3):260–268. http://www.ncbi.nlm.nih.gov/pubmed/22267201
Christensen DL, Eis J, Hansen AW, Larsson MW, Mwaniki DL, Kilonzo B et al (2008) Obesity and regional fat distribution in Kenyan populations: impact of ethnicity and urbanization. Ann Hum Biol 35(2):232–249
Osuch JR, He J (2000) Current knowledge and new insights into the effects of reproductive and hormonal risk factors in black and white populations. Cancer 88:1230–1238
Kobayashi S, Sugiura H, Ando Y, Shiraki N, Yanagi T, Yamashita H et al (2012) Reproductive history and breast cancer risk. Breast Cancer 19(4):302–308
Sighoko D, Ogundiran T, Ademola A, Adebamowo C, Chen L, Odedina S et al (2015) Breast cancer risk after full-term pregnancies among African women from Nigeria, Cameroon, and Uganda. Cancer 121(13):2237–2243
Watson BM, Watson B (2013) Ethnicity and breastfeeding in kenya ethnicity and breastfeeding in Kenya. University of Tennessee Honors Thesis Projects. http://trace.tennessee.edu/utk_chanhonoproj/1642
Palmer JR, Boggs DA, Wise LA, Ambrosone CB, Adams-Campbell LL, Rosenberg L (2011) Parity and lactation in relation to estrogen receptor negative breast cancer in African American women. Cancer Epidemiol Biomark Prev 20(9):1883–1891
Kenya Demographics Profile (2017). https://www.indexmundi.com/kenya/demographics_profile.html
Acknowledgements
The authors would like to thank GSK-ERI for funding, administrative staff of Aga Khan University, all participating institutions, and all nurses and technologists at the participating sites. In addition, the authors would like to thank Angela Mutuku and Gaylord Mwangi (AKU) for their assistance in formatting and assistance with the illustrations in this manuscript. This study was supported in part by the Intramural Research Program of the Division of Cancer Epidemiology and Genetics of the U.S. National Cancer Institute.
Author information
Authors and Affiliations
Contributions
SS, ZM, and MS conceived and carried out the study; SS, ZM, PO, and SG carried out the centralized laboratory work; IA, CK, TH, and SM performed data management; TH, SM, CK, GLG, SF, MM, and MP analyzed the data; RW, PB, RO, FWN, AJ, SVP, SV, RC, AZ, MM, BB, CM, OAS, AM, AG, JG, JK, RN, RN, IM, JOO, DOR, EBM, and IA contributed to data collection and/or data management. All authors were involved in writing/reviewing the manuscript. All authors gave final approval of the submitted version of the manuscript.
Corresponding author
Ethics declarations
Conflict of interest
All the authors have no competing interest to declare.
Ethical approval
Aga Khan University Hospital, Nairobi Research and Ethics Committee (REF: 2011/25), and the institutional review boards of all participating health facilities approved the study. Written informed consent was obtained from all study participants.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
Sayed, S., Moloo, Z., Wasike, R. et al. Ethnicity and breast cancer characteristics in Kenya. Breast Cancer Res Treat 167, 425–437 (2018). https://doi.org/10.1007/s10549-017-4511-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10549-017-4511-2