MUC1 overexpression is the most reliable marker of invasive carcinoma in intraductal papillary-mucinous tumor (IPMT).
OBJECTIVE
To clarify the development of pancreatic cancer we performed immunohistochemical analysis of the presence of the major apomucin and cell-cycle regulatory proteins using the tissues of IPMT and ductal adenocarcinoma (DC) of the pancreas.


METHODS
Formalin-fixed and paraffin-embedded tissues of 24 IPMT and 21 DC cases were subjected to immunohistochemical staining for MUC1, MUC2, p16, p53 and DPC4. According to the WHO classification, there were 10 intraductal papillary-mucinous adenomas (IPMA); 3 borderline intraductal papillary-mucinous neoplasms (IPMB); 4 intraductal papillary-mucinous carcinomas (IPMC), non-invasive type (nIPMC); 4 IPMCs with invasive muci nous carcinoma (IPMC/muc); and 3 IPMCs with invasive tubular adenocarcinoma (IPMC/tub).


RESULTS
MUC1 expression was seen in 6 of 7 invasive IPMCs (86%) and in all DCs (100%). MUC2 was only seen in non-invasive IPMT and in a part of IPMC/muc. p53 nuclear staining was positive only in 3 of 7 invasive IPMCs (43%) and 9 of 21 DCs (43%). DPC4 nuclear expression was positive in almost all cases of non-invasive IPMT, but negative or reduced in 4 of 7 invasive IPMCs (57%), and 14 of 21 DCs (67%).


CONCLUSIONS
MUC1 overexpression is considered to be the most sensitive and specific marker of invasive carcinoma, followed by DPC4 and p53 with less sensitivity.
Ueda
Michio
M
Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan. michiou@med.yokohama-cu.ac.jp
Miura
Yasuhiko
Y
Kunihiro
Osamu
O
Ishikawa
Takashi
T
Ichikawa
Yasushi
Y
Endo
Itaru
I
Sekido
Hitoshi
H
Togo
Shinji
S
Shimada
Hiroshi
H
D002288:Adenocarcinoma, Mucinous / Q000378:metabolism / Q000473:pathology*; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology*; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008875:Middle Aged; D018396:Mucin-1 / Q000378:metabolism*; D055262:Mucin-2; D009077:Mucins / Q000378:metabolism; D009361:Neoplasm Invasiveness; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D051901:Smad4 Protein; D013194:Staining and Labeling; D015534:Trans-Activators / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D014408:Biomarkers, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16; D004268:DNA-Binding Proteins; C524625:MUC2 protein, human; D018396:Mucin-1; D055262:Mucin-2; D009077:Mucins; C497796:SMAD4 protein, human; D051901:Smad4 Protein; D015534:Trans-Activators; D016159:Tumor Suppressor Protein p53