The expression pattern of MUC1 (EMA) is related to tumour characteristics and clinical outcome in 'pure' ductal carcinoma in situ of the breast.
OBJECTIVE
To classify MUC1 according to five predefined expression patterns in ductal carcinoma in situ (DCIS) and related clinicopathological parameters, coexpression of other biological markers and prognosis.


RESULTS
With a manual tissue arrayer, 92% (n = 80) of the 87 DCIS samples were successfully targeted. Immunohistochemistry was carried out for MUC1, oestrogen receptor (ER), progesterone receptor (PR), Her2/Neu, p53 and cyclin D1. Entire membrane expression was related to Her2/neu negativity (P =0.042). Apical membrane expression was associated with low grade (P = 0.027), Her2/neu negativity (P = 0.014) and PR positivity (P = 0.005). Focal cytoplasmic expression was related to high grade (P = 0.006). Diffuse cytoplasmic expression was associated with high grade (P = 0.004), large tumour size (P = 0.046), Her2/neu positivity (P =0.042) and cyclin D1 positivity (P = 0.002). On the basis of these analyses the four patterns were reclassified as membranous or cytoplasmic expression. On multivariate analysis, cytoplasmic MUC1 expression (hazard ratio 8.5, 95% confidence interval 1.0, 73.0; P = 0.04) was the only independent predictor of local recurrence.


CONCLUSIONS
Four patterns of MUC1 expression are recognized in DCIS that suggest a relationship to functional differentiation and can be simplified into two types that are clinically relevant and could therefore be helpful in the distinction between different subgroups of DCIS.
de Roos
M A J
MA
Department of Surgical Oncology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands.
van der Vegt
B
B
Peterse
J L
JL
Patriarca
C
C
de Vries
J
J
de Bock
G H
GH
Wesseling
J
J
D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D056741:Cyclin D; D016213:Cyclins / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015412:Mastectomy, Segmental; D046228:Microarray Analysis; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism*; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000473:pathology; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D014408:Biomarkers, Tumor; D056741:Cyclin D; D016213:Cyclins; D018396:Mucin-1; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D016159:Tumor Suppressor Protein p53; C495901:TP53 protein, human; C508053:ERBB2 protein, human