Albergaria et al. BMC Cancer 2011, 11:299 http://www.biomedcentral.com/1471-2407/11/299 5. Diaz LK, Cryns VL, Symmans WF, Sneige N: Triple negative breast carcinoma and the basal phenotype: from expression profiling to clinical practice. Adv Anat Pathol 2007, 14(6):419-430. 6. Perou CM, Sorlie T, Eisen MB, van de Rijn M, Jeffrey SS, Rees CA, Pollack JR, Ross DT, Johnsen H, Akslen LA, et al: Molecular portraits of human breast tumours. Nature 2000, 406(6797):747-752. 7. Perou CM, Jeffrey SS, van de Rijn M, Rees CA, Eisen MB, Ross DT, Pergamenschikov A, Williams CF, Zhu SX, Lee JC, et al: Distinctive gene expression patterns in human mammary epithelial cells and breast cancers. Proc Natl Acad Sci USA 1999, 96(16):9212-9217. 8. Sorlie T, Perou CM, Tibshirani R, Aas T, Geisler S, Johnsen H, Hastie T, Eisen MB, van de Rijn M, Jeffrey SS, et al: Gene expression patterns of breast carcinomas distinguish tumor subclasses with clinical implications. Proc Natl Acad Sci USA 2001, 98(19):10869-10874. 9. Sorlie T, Tibshirani R, Parker J, Hastie T, Marron JS, Nobel A, Deng S, Johnsen H, Pesich R, Geisler S, et al: Repeated observation of breast tumor subtypes in independent gene expression data sets. Proc Natl Acad Sci USA 2003, 100(14):8418-8423. 10. Brenton JD, Carey LA, Ahmed AA, Caldas C: Molecular classification and molecular forecasting of breast cancer: ready for clinical application? J Clin Oncol 2005, 23(29):7350-7360. 11. Reis-Filho JS, Tutt AN: Triple negative tumours: a critical review. Histopathology 2008, 52(1):108-118. 12. Reis-Filho JS, Westbury C, Pierga JY: The impact of expression profiling on prognostic and predictive testing in breast cancer. J Clin Pathol 2006, 59(3):225-231. 13. Hu Z, Fan C, Oh DS, Marron JS, He X, Qaqish BF, Livasy C, Carey LA, Reynolds E, Dressler L, et al: The molecular portraits of breast tumors are conserved across microarray platforms. BMC Genomics 2006, 7:96. 14. Parker JS, Mullins M, Cheang MC, Leung S, Voduc D, Vickery T, Davies S, Fauron C, He X, Hu Z, et al: Supervised risk predictor of breast cancer based on intrinsic subtypes. J Clin Oncol 2009, 27(8):1160-1167. 15. Rakha EA, Reis-Filho JS, Ellis IO: Basal-like breast cancer: a critical review. J Clin Oncol 2008, 26(15):2568-2581. 16. Gusterson BA, Ross DT, Heath VJ, Stein T: Basal cytokeratins and their relationship to the cellular origin and functional classification of breast cancer. Breast Cancer Res 2005, 7(4):143-148. 17. Jones C, Mackay A, Grigoriadis A, Cossu A, Reis-Filho JS, Fulford L, Dexter T, Davies S, Bulmer K, Ford E, et al: Expression profiling of purified normal human luminal and myoepithelial breast cells: identification of novel prognostic markers for breast cancer. Cancer Res 2004, 64(9):3037-3045. 18. Lakhani SR, O’Hare MJ: The mammary myoepithelial cell–Cinderella or ugly sister? Breast Cancer Res 2001, 3(1):1-4. 19. Nofech-Mozes S, Trudeau M, Kahn HK, Dent R, Rawlinson E, Sun P, Narod SA, Hanna WM: Patterns of recurrence in the basal and non-basal subtypes of triple-negative breast cancers. Breast Cancer Res Treat 2009, 118(1):131-137. 20. Matos I, Dufloth R, Alvarenga M, Zeferino LC, Schmitt F: p63, cytokeratin 5, and P-cadherin: three molecular markers to distinguish basal phenotype in breast carcinomas. Virchows Arch 2005, 447(4):688-694. 21. Nielsen TO, Hsu FD, Jensen K, Cheang M, Karaca G, Hu Z, Hernandez- Boussard T, Livasy C, Cowan D, Dressler L, et al: Immunohistochemical and clinical characterization of the basal-like subtype of invasive breast carcinoma. Clin Cancer Res 2004, 10(16):5367-5374. 22. Paredes J, Correia AL, Ribeiro AS, Albergaria A, Milanezi F, Schmitt FC: P- cadherin expression in breast cancer: a review. Breast Cancer Res 2007, 9(5):214.. 23. Paredes J, Lopes N, Milanezi F, Schmitt FC: P-cadherin and cytokeratin 5: useful adjunct markers to distinguish basal-like ductal carcinomas in situ. Virchows Arch 2007, 450(1):73-80. 24. Savage K, Lambros MB, Robertson D, Jones RL, Jones C, Mackay A, James M, Hornick JL, Pereira EM, Milanezi F, et al: Caveolin 1 is overexpressed and amplified in a subset of basal-like and metaplastic breast carcinomas: a morphologic, ultrastructural, immunohistochemical, and in situ hybridization analysis. Clin Cancer Res 2007, 13(1):90-101. 25. Savage K, Leung S, Todd SK, Brown LA, Jones RL, Robertson D, James M, Parry S, Rodrigues Pinilla SM, Huntsman D, et al: Distribution and significance of caveolin 2 expression in normal breast and invasive breast cancer: an immunofluorescence and immunohistochemical analysis. Breast Cancer Res Treat 2008, 110(2):245-256. Page 9 of 10 26. Arnes JB, Brunet JS, Stefansson I, Begin LR, Wong N, Chappuis PO, Akslen LA, Foulkes WD: Placental cadherin and the basal epithelial phenotype of BRCA1-related breast cancer. Clin Cancer Res 2005, 11(11):4003-4011. 27. Sitterding SM, Wiseman WR, Schiller CL, Luan C, Chen F, Moyano JV, Watkin WG, Wiley EL, Cryns VL, Diaz LK: AlphaB-crystallin: a novel marker of invasive basal-like and metaplastic breast carcinomas. Ann Diagn Pathol 2008, 12(1):33-40. 28. Paredes J, Albergaria A, Oliveira JT, Jeronimo C, Milanezi F, Schmitt FC: P- cadherin overexpression is an indicator of clinical outcome in invasive breast carcinomas and is associated with CDH3 promoter hypomethylation. Clin Cancer Res 2005, 11(16):5869-5877. 29. Albergaria A, Ribeiro AS, Pinho S, Milanezi F, Carneiro V, Sousa B, Sousa S, Oliveira C, Machado JC, Seruca R, et al: ICI 182,780 induces P-cadherin overexpression in breast cancer cells through chromatin remodelling at the promoter level: a role for C/EBPα in CDH3 gene activation. Hum Mol Genet 2010, 11(13):2554-2566. 30. Weigelt B, Mackay A, A’Hern R, Natrajan R, Tan DS, Dowsett M, Ashworth A, Reis-Filho JS: Breast cancer molecular profiling with single sample predictors: a retrospective analysis. Lancet Oncol 2010, 11:339-349. 31. Cheang MC, Voduc D, Bajdik C, Leung S, McKinney S, Chia SK, Perou CM, Nielsen TO: Basal-like breast cancer defined by five biomarkers has superior prognostic value than triple-negative phenotype. Clin Cancer Res 2008, 14(5):1368-1376. 32. Fulford LG, Reis-Filho JS, Ryder K, Jones C, Gillett CE, Hanby A, Easton D, Lakhani SR: Basal-like grade III invasive ductal carcinoma of the breast: patterns of metastasis and long-term survival. Breast Cancer Res 2007, 9(1):R4.. 33. Rakha E, Ellis I, Reis-Filho J: Are triple-negative and basal-like breast cancer synonymous? Clin Cancer Res 2008, 14(2):618, author reply 618-619. 34. Reis-Filho JS, Milanezi F, Steele D, Savage K, Simpson PT, Nesland JM, Pereira EM, Lakhani SR, Schmitt FC: Metaplastic breast carcinomas are basal-like tumours. Histopathology 2006, 49(1):10-21. 35. Irvin WJ jr, Carey LA: What is triple-negative breast cancer? Eur J Cancer 2008, 44(18):2799-2805. 36. Kreike B, van Kouwenhove M, Horlings H, Weigelt B, Peterse H, Bartelink H, van de Vijver MJ: Gene expression profiling and histopathological characterization of triple-negative/basal-like breast carcinomas. Breast Cancer Res 2007, 9(5):R65. 37. Sotiriou C, Pusztai L: Gene-expression signatures in breast cancer. N Engl J Med 2009, 360(8):790-800. 38. Rakha EA, Elsheikh SE, Aleskandarany MA, Habashi HO, Green AR, Powe DG, El-Sayed ME, Benhasouna A, Brunet JS, Akslen LA, et al: Triple-negative breast cancer: distinguishing between basal and nonbasal subtypes. Clin Cancer Res 2009, 15(7):2302-2310. 39. Dent R, Hanna WM, Trudeau M, Rawlinson E, Sun P, Narod SA: Pattern of metastatic spread in triple-negative breast cancer. Breast Cancer Res Treat 2009, 115(2):423-428. 40. Dent R, Trudeau M, Pritchard KI, Hanna WM, Kahn HK, Sawka CA, Lickley LA, Rawlinson E, Sun P, Narod SA: Triple-negative breast cancer: clinical features and patterns of recurrence. Clin Cancer Res 2007, 13(15):4429-4434. 41. Tischkowitz M, Brunet JS, Begin LR, Huntsman DG, Cheang MC, Akslen LA, Nielsen TO, Foulkes WD: Use of immunohistochemical markers can refine prognosis in triple negative breast cancer. BMC Cancer 2007, 7:134. 42. Hicks DG, Short SM, Prescott NL, Tarr SM, Coleman KA, Yoder BJ, Crowe JP, Choueiri TK, Dawson AE, Budd GT, et al: Breast cancers with brain metastases are more likely to be estrogen receptor negative, express the basal cytokeratin CK5/6, and overexpress HER2 or EGFR. Am J Surg Pathol 2006, 30(9):1097-1104. 43. Rodriguez-Pinilla SM, Sarrio D, Honrado E, Hardisson D, Calero F, Benitez J, Palacios J: Prognostic significance of basal-like phenotype and fascin expression in node-negative invasive breast carcinomas. Clin Cancer Res 2006, 12(5):1533-1539. 44. Tsuda H, Takarabe T, Hasegawa T, Murata T, Hirohashi S: Myoepithelial differentiation in high-grade invasive ductal carcinomas with large central acellular zones. Hum Pathol 1999, 30(10):1134-1139. 45. Lee AH, Ellis IO: The Nottingham prognostic index for invasive carcinoma of the breast. Pathol Oncol Res 2008, 14(2):113-115. 46. Miller DV, Leontovich AA, Lingle WL, Suman VJ, Mertens ML, Lillie J, Ingalls KA, Perez EA, Ingle JN, Couch FJ, et al: Utilizing Nottingham