Background. Recently, gene expression profiling and its surrogate immunohistochemistry (IHC) markers classified breast cancer into four distinct molecular subtypes, which have different prognoses, targeted therapies, and/or clinical outcomes. Objective. To conduct a preliminary study, to correlate the clinical pathological profiles and taxonomy of molecular subtypes of breast cancer in Eritrea, in the Horn of Africa. Design. Review of pathology reports from Jan. 1 to Nov. 30, 2009, provided 22 cases of microscopically confirmed invasive breast carcinoma that were evaluable for histology and IHC (ER, PR, HER2, and Cytokeratin 5/6). Result. Twenty patients were female and most of them (68%) were under 50 years at presentation. 90% were invasive invasive carcinoma of no special type and were histological grade 3. The molecular subtypes were luminal A (55%), luminal B (5%), HER2 (5%), basal-like (10%), and unclassified (25%). Triple negative carcinoma (basal-like and unclassified combined) was 35%, mostly (71%) in women under 50 years with grade 3 tumours. Conclusion. Breast carcinoma in Eritrean women presents at a younger age and with a high histologic grade. The two predominant molecular subtypes are luminal A and triple negative. Determining the molecular subtype using surrogate IHC markers has important treatment and prognostic implications for Eritrean women with breast cancer. 1. Introduction Among women, breast cancer is the leading cause of cancer-related death in the world [1]. The lowest incidence is in Africa; however, the incidence has recently been increasing and is accompanied by increased mortality [1, 2]. Breast cancer in African and African-American women is characterized by late presentation, younger age, advanced stage, higher grade, more negative hormonal receptor status, and poorer prognosis, when compared to Caucasian American and western European women [3–6]. Although the causes for these disparities may include socioeconomic status, access to screening, and differences in treatment decisions, the intrinsic biology of the disease itself may play a role in the different outcomes [7–9]. Today, breast cancer is considered to be a heterogeneous disease, consisting of different molecular subtypes which correlate with disease outcomes independent of other factors. Gene expression microarrays have identified distinct breast cancer molecular subtypes, including two types of estrogen receptor (ER) negative tumors: basal-like and human epidermal growth receptor (HER2) enriched, and two types of ER-positive tumors: luminal A and luminal B [10,
References
[1]
J. Ferlay, H. R. Shin, F. Bray, D. Forman, C. Mathers, and D. M. Parkin, “Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008,” International Journal of Cancer, vol. 127, no. 12, pp. 2893–2917, 2010.
[2]
G. N. Hortobagyi, J. de la Garza Salazar, K. Pritchard et al., “The global breast cancer burden: variations in epidemiology and survival,” Clinical Breast Cancer, vol. 6, no. 5, pp. 391–401, 2005.
[3]
J. W. Eloy, H. A. Hill, V. W. Chen et al., “Racial differences in survival from breast cancer: results of the National Cancer Institute Black/White Cancer Survival Study,” Journal of the American Medical Association, vol. 272, no. 12, pp. 947–954, 1994.
[4]
R. T. Chlebowski, Z. Chen, G. L. Anderson et al., “Ethnicity and breast cancer: factors influencing differences in incidence and outcome,” Journal of the National Cancer Institute, vol. 97, no. 6, pp. 439–448, 2005.
[5]
K. C. Chu and W. F. Anderson, “Rates for breast cancer characteristics by estrogen and progesterone receptor status in the major racial/ethnic groups,” Breast Cancer Research and Treatment, vol. 74, no. 3, pp. 199–211, 2002.
[6]
R. L. Bowen, S. W. Duffy, D. A. Ryan, I. R. Hart, and J. L. Jones, “Early onset of breast cancer in a group of British black women,” British Journal of Cancer, vol. 98, no. 2, pp. 277–281, 2008.
[7]
R. Smith-Bindman, D. L. Miglioretti, N. Lurie et al., “Does utilization of screening mammography explain racial and ethnic differences in breast cancer?” Annals of Internal Medicine, vol. 144, no. 8, pp. 541–553, 2006.
[8]
L. A. Newman, K. A. Griffith, I. Jatoi, M. S. Simon, J. P. Crowe, and G. A. Colditz, “Meta-analysis of survival in African American and white American patients with breast cancer: ethnicity compared with socioeconomic status,” Journal of Clinical Oncology, vol. 24, no. 9, pp. 1342–1349, 2006.
[9]
C. M. Perou, T. S？rile, M. B. Eisen et al., “Molecular portraits of human breast tumours,” Nature, vol. 406, no. 6797, pp. 747–752, 2000.
[10]
T. S？rlie, C. M. Perou, R. Tibshirani et al., “Gene expression patterns of breast carcinomas distinguish tumor subclasses with clinical implications,” Proceedings of the National Academy of Sciences of the United States of America, vol. 98, no. 19, pp. 10869–10874, 2001.
[11]
T. S？rlie, R. Tibshirani, J. Parker et al., “Repeated observation of breast tumor subtypes in independent gene expression data sets,” Proceedings of the National Academy of Sciences of the United States of America, vol. 100, no. 14, pp. 8418–8423, 2003.
[12]
L. A. Carey, C. M. Perou, C. A. Livasy et al., “Race, breast cancer subtypes, and survival in the Carolina Breast Cancer Study,” Journal of the American Medical Association, vol. 295, no. 21, pp. 2492–2502, 2006.
[13]
T. O. Nielsen, F. D. Hsu, K. Jensen, et al., “Immunohistochemical and clinical characterization of the basal-like subtype of invasive breast carcinoma,” Clinical Cancer Research, vol. 10, pp. 5367–5374, 2004.
[14]
D. Huo, F. Ikpatt, A. Khramtsov et al., “Population differences in breast cancer: survey in indigenous african women reveals over-representation of triple-negative breast cancer,” Journal of Clinical Oncology, vol. 27, no. 27, pp. 4515–4521, 2009.
[15]
C. A. Adebamowo, A. Famooto, T. O. Ogundiran, T. Aniagwu, C. Nkwodimmah, and E. E. Akang, “Immunohistochemical and molecular subtypes of breast cancer in Nigeria,” Breast Cancer Research and Treatment, vol. 110, no. 1, pp. 183–188, 2008.
[16]
B. S. Coya Tapia, A. Elia Ishak, S. Gaber, et al., “Molecular subtype analysis determines the association of advanced breast cancer in Egypt with favorable biology,” Journal of BMC Womens' Health, vol. 44, no. 11, pp. 1472–11478, 2011.
[17]
K. D. Awadelkarim, C. Arizzi, E. O. M. Elamin et al., “Pathological, clinical and prognostic characteristics of breast cancer in Central Sudan versus Northern Italy: implications for breast cancer in Africa,” Histopathology, vol. 52, no. 4, pp. 445–456, 2008.
[18]
K. D. Awadelkarim, C. Arizzi, E. O. M. Elamin, et al., “Basal-like phenotype in a breast carcinoma case series from Sudan: prevalence and clinical/pathological correlations,” Pathology Research International, vol. 2011, Article ID 806831, 10 pages, 2011.
[19]
C. Fan, D. S. Oh, L. Wessels et al., “Concordance among gene-expression-based predictors for breast cancer,” The New England Journal of Medicine, vol. 355, no. 6, pp. 560–569, 2006.
[20]
K. M. O'Brien, S. R. Cole, C. K. Tse et al., “Intrinsic breast tumor subtypes, race, and long-term survival in the carolina breast cancer study,” Clinical Cancer Research, vol. 16, no. 24, pp. 6100–6110, 2010.
[21]
P. A. Bird, A. G. Hill, and N. Houssami, “Poor hormone receptor expression in East African breast cancer: evidence of a biologically different disease?” Annals of Surgical Oncology, vol. 15, no. 7, pp. 1983–1988, 2008.
[22]
R. Bhikoo, S. Srinivasa, T. C. Yu, D. Moss, and A. G. Hill, “Systematic review of breast cancer biology in developing countries (part 1): Africa, the Middle East, Eastern Europe, Mexico, the Caribbean and South America,” Cancers, vol. 3, no. 2, pp. 2358–2381, 2011.
[23]
A. C. Wolff, M. E. Hammond, J. N. Schwartz, et al., “American Society of Clinical Oncology/ College of American Pathologists guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer,” Journal of Clinical Oncology, vol. 25, pp. 118–145, 2007.
[24]
A. K. El-Hawary, A. S. Abbas, A. A. Elsayed, and K. R. Zalata, “Molecular subtypes of breast carcinoma in Egyptian women: clinicopathological features,” Pathology, vol. 208, no. 7, pp. 382–386, 2012.
[25]
I. Roy and E. Othieno, “Breast carcinoma in Uganda: microscopic study and receptor profile of 45 cases,” Archives of Pathology and Laboratory Medicine, vol. 135, no. 2, pp. 194–199, 2011.
[26]
K. A. Cronin, L. C. Harlan, K. W. Dodd, J. S. Abrams, and R. Ballard-Barbash, “Population-based estimate of the prevalence of HER-2 positive breast cancer tumors for early stage patients in the US,” Cancer Investigation, vol. 28, no. 9, pp. 963–968, 2010.
[27]
K. A. Adeniji, D. Huo, A. Khramtsov, C. Zhang, and O. I. Olopade, “Molecular profiles of breast cancer in Ilorin, Nigeria,” Journal of Clinical Oncology, vol. 28, no. 15, supplement, 2010, abstract no.1602.
[28]
K. E. Malone, J. R. Daling, D. R. Doody et al., “Prevalence and predictors of BRCA1 and BRCA2 mutations in a population-based study of breast cancer in White and Black American women ages 35 to 64 years,” Cancer Research, vol. 66, no. 16, pp. 8297–8308, 2006.
[29]
C. K. Anders and L. A. Carey, “Biology, metastatic patterns, and treatment of patients with triple-negative breast cancer,” Clinical Breast Cancer, vol. 9, no. 2, pp. S73–S81, 2009.
[30]
A. Tesfamariam, A. Gebremichael, and J. Mufunda, “Overview of breast cancer clinicopathological presentation, gravity, and challenge in Eritrea,” South African Medical Journal. In press.
