Investigation of breast cancer sub-populations in black and white women in South Africa
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Bimodal age distributions at diagnosis have been widely observed among US and European female breast cancer populations. To determine whether bimodal breast cancer distributions are also present in a sub-Saharan African population, we investigated female breast cancer in South Africa.
Using the South African National Cancer Registry data, we examined age-at-diagnosis frequency distributions (density plots) for breast cancer overall and by their receptor (oestrogen, progesterone and HER2) determinants among black and white women diagnosed during 2009–2011 in the public healthcare sector. For comparison, we also analysed corresponding 2010–2011 US SEER data. We investigated density plots using flexible mixture models, allowing early/late-onset membership to depend on receptor status.
We included 8857 women from South Africa, 7176 (81 %) with known oestrogen receptor status, and 95064 US women. Bimodality was present in all races, with an early-onset mode between ages 40–50 years and a late-onset mode among ages 60–70 years. The early-onset mode was younger in South African black women (age 38), compared to other groups (45–54 years).
Consistent patterns of bimodality and of its receptor determinants were present across breast cancer patient populations in South Africa and the US. Although the clinical spectrum of breast cancer is well acknowledged as heterogeneous, universal early- and late-onset age distributions at diagnosis suggest that breast cancer etiology consists of a mixture two main types.
KeywordsBreast cancer Receptors Age distributions South Africa
Akaike information criterion
Fluorescence in situ hybridization
Human-epidermal growth factor-2 enriched (ER−PR−HER2+)
Surveillance, Epidemiology, and End Results
The work reported in this paper was undertaken during the tenure of a Postdoctoral Fellowship to Dr Dickens from the International Agency for Research on Cancer, partially supported by the European Commission FP7 Marie Curie Actions – People – Co-funding of regional, national and international programmes (COFUND).
Compliance with ethical standards
Conflict of Interest
The authors declare that they have no conflicts of interest.
- 10.Dickens C, Duarte R, Zietsman A, Cubasch H, Kellett P, Schuz J et al (2014) Racial comparison of receptor-defined breast cancer in Southern African women: subtype prevalence and age-incidence analysis of nationwide cancer registry data. Cancer Epidemiol Biomark Prev 23(11):2311–2321CrossRefGoogle Scholar
- 11.National Cancer Registry (2012) Cancer in South Africa 2006 Full Report. National Health Laboratory ServiceGoogle Scholar
- 13.Surveillance Epidemiology and End Results (SEER) Program (www.seer.cancer.gov). SEER*Stat Database: Incidence—SEER 18 Regs Research Data+ Hurricane Katrina Impacted Louisiana Cases, Nov 2013 Sub (1973-2011 varying)—Linked To County Attributes—Total U.S., 1969–2012 Counties, National Cancer Institute, DCCPS, Surveillance Research Program, Surveillance Systems Branch, released April 2014 (updated 5/7/2014), based on the November 2013 submission. www. seer. cancer. gov 2014
- 20.Dickens C, Joffe M, Jacobson J, Venter F, Schuz J, Cubasch H et al (2014) Stage at breast cancer diagnosis and distance from diagnostic hospital in a peri-urban setting: a South African public hospital case series of over 1000 women. Int J Cancer 135(9):2173–2182CrossRefPubMedPubMedCentralGoogle Scholar
- 22.Ferlay J, Soerjomataram I, Dikshit R, Eser S, Mathers C, Rebelo M, et al (2013) GLOBOCAN 2012 v1.0, Cancer incidence and mortality worldwide: IARC CancerBase No. 10 [Internet]. Lyon, France: International Agency for Research on Cancer. http://globocan.iarc.fr. Accessed on 20 Dec 2013)
- 23.Statistics SA (2010) Estimation of fertility from the 2007 community survey of South Africa. no. 03-00-04 (2010) ed. Pretoria South Africa : Statistics South AfricaGoogle Scholar
- 24.Statistics South Africa 2011 National Census. http://interactive.statssa.gov.za/superweb/login.do2013 [cited 4 Feb 2013]