Mucin expression profile is related to biological and clinical characteristics of intraductal papillary-mucinous tumors of the pancreas.
OBJECTIVE
Biologic and clinical characteristics of intraductal papillary-mucinous tumors of the pancreas (IPMTs) were studied in reference to immunohistochemical mucin (MUC1, MUC2, and MUC5AC) expression.


METHODS
Histologic grade, immunohistochemical ki-67 and p53 expression, and findings in imaging tests of 21 IPMTs (9 carcinomas, 6 borderline tumors, and 6 adenomas) were examined according to the mucin expression profile.


RESULTS
IPMTs were divided into groups: M1 group (MUC1+, n = 4), M2 group (MUC2 + MUC1-, n = 12), and M5 group (MUC5AC + MUC1-MUC2-, n = 5). The M2 group was subdivided into M2s (strongly positive) and M2w (weakly positive) groups. The rates of carcinoma in the M1, M2s, M2w, and M5 groups were 100%, 40%, 0%, and 0%, respectively. The Ki-67 labeling indexes were significantly higher in the M1 and M2s groups. p53 staining was positive in 50% and 40% of the IPMTs in the M1 and M2s groups, respectively, but in none of the IPMT in the M2w and M5 groups. Morphologic changes in imaging tests during the observation periods were most remarkable in the M1 group.


CONCLUSIONS
Our results suggest that MUC1 is related to malignant character but MUC5AC alone is related to benign character in IPMTs and that malignant potential of IPMTs expressing MUC2 depends on the degree of MUC2 expression.
Ito
Hideto
H
First Department of Internal Medicine, Sapporo Medical University, School of Medicine, Sapporo, Japan. hideto@nsp.hosp.go.jp
Endo
Takao
T
Oka
Toshikuni
T
Matumoto
Takeshi
T
Abe
Tamaki
T
Toyota
Minoru
M
Imai
Kohzoh
K
Satoh
Masaaki
M
Maguchi
Hiroyuki
H
Shinohara
Toshiya
T
D002288:Adenocarcinoma, Mucinous / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D002291:Carcinoma, Papillary / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D055271:Mucin 5AC; D018396:Mucin-1 / Q000378:metabolism; D055262:Mucin-2; D009077:Mucins / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; C524625:MUC2 protein, human; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D018396:Mucin-1; D055262:Mucin-2; D009077:Mucins; D016159:Tumor Suppressor Protein p53