CGH analysis of ductal carcinoma of the breast with basaloid/myoepithelialcell differentiation

2-18% of ductal carcinoma-No Special Type (NST) are reported to express bas al cell keratin 14 and such tumours may have a different metastatic pattern and prognosis. We performed immunohistochemistry for cytokeratins 19 (lumi nal) and 14 (basal) on 92 ductal carcinoma-NST. Those tumours showing CK14 expression were further characterized by immunohistochemistry for myoepithe lial cell phenotype and analysed by comparative genomic hybridization. The 7 cases of ductal carcinoma-NST exhibiting a basal cell phenotype were all grade III tumours and showed a molecular cytogenetic profile similar to mor e conventional myoepithelial cell carcinomas. Therefore it appears that gra de Ill invasive ductal carcinomas contain a subset of tumours with specific morphological and cytogenetic characteristics, and probably prognosis for the patient. (C) 2001 Cancer Research Campaign.