Specific morphological features predictive for the basal phenotype in grade 3 invasive ductal carcinoma of breast.
OBJECTIVE
Cytokeratin (CK) 14, a myoepithelial marker, is also expressed in a proportion of breast carcinomas. There is evidence that these tumours show a differing metastatic pattern and clinical outcome from other invasive ductal carcinomas (IDCs) and may need different management. Currently, they are not identified in routine practice and no morphological guidelines exist to aid their identification. The aim of this study was to analyse the histological features of CK14+ IDC.


RESULTS
A detailed histological review of 453 grade 3 IDCs revealed 88 (19.4%) that expressed CK14. Assessment was made independently by two pathologists using a standardized 'tick-box' proforma covering grade, architectural and cytological features. The results were analysed using logistic regression to identify features that predicted for basal phenotype. Concordance between the two pathologists was fair to good for most parameters (kappa 0.4-0.6). On multiple logistic regression, the basal phenotype was highly significantly associated with the presence of a central scar (P = 0.005), tumour necrosis (P < 0.0001), presence of spindle cells (P = 0.006) or squamous metaplasia (P < 0.0001), high total mitotic count (> 40 per 10 high-power field) (P = 0.0002) and high nuclear-cytoplasmic ratio (P = 0.0002).


CONCLUSIONS
Specific morphological features are strongly associated with basal-like breast carcinoma. These could be used in routine diagnostic practice to identify this important subset of tumours.
Fulford
L G
LG
The Breakthrough Breast Cancer Research Centre, London, UK. laura.work@gmail.com
Easton
D F
DF
Reis-Filho
J S
JS
Sofronis
A
A
Gillett
C E
CE
Lakhani
S R
SR
Hanby
A
A
D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D018270:Carcinoma, Ductal, Breast / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053547:Keratin-14; D007633:Keratins / Q000378:metabolism; D018295:Neoplasms, Basal Cell / Q000145:classification / Q000378:metabolism / Q000473:pathology; D010641:Phenotype
D014408:Biomarkers, Tumor; C507540:KRT14 protein, human; D053547:Keratin-14; D007633:Keratins