Biologically different subgroups of invasive ductal carcinoma of the pancreas: Dpc4 status according to the ratio of intraductal carcinoma components.
OBJECTIVE
Among invasive ductal carcinomas of the pancreas (IDCP), there is a morphologically characteristic subgroup accompanied by abundant intraductal carcinoma components (ICCs). With the aim of determining whether ICC-rich IDCP are biologically different from ICC-poor IDCP, the expression status of Dpc4 protein was analyzed.


METHODS
A total of 43 IDCP was subdivided into two groups: (a). ICC-rich IDCP (ICCs area occupies >or=10% of the entire tumorous area); and (b). ICC-poor IDCP (with <10% of ICCs area). A total of 10 invasive carcinomas derived from intraductal papillary-mucinous neoplasms (ICs from IPMNs) were also analyzed. Each invasive and intraductal carcinoma area was then evaluated for Dpc4 protein status by immunohistochemistry.


RESULTS
In a total of 43 IDCP, there were 23 ICC-rich IDCP and 20 ICC-poor IDCP. Dpc4-positive immunostaining was observed in the invasive carcinoma component of ICC-rich IDCP, ICC-poor IDCP, and ICs from IPMN in 18 of 23 (78%), 4 of 20 (20%), and 7 of 10 (70%) cases, respectively. In the intraductal component, positive staining for Dpc4 was found in 20 of 23 (87%), 3 of 7 (41%), and 8 of 10 (80%) cases, respectively. Dpc4 expression was found in both the invasive and ICC components of ICC-rich IDCP, similar to that found in IC derived from IPMN, whereas the expression of Dpc4 was largely diminished in ICC-poor IDCP.


CONCLUSIONS
Morphologically distinct subgroups of invasive ductal carcinomas of the pancreas, namely ICC-rich IDCP and ICC-poor IDCP, are also biologically distinguishable as revealed by the differential expression of Dpc4.
Takahashi
Hidenori
H
Pathology Division, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
Oda
Tatsuya
T
Hasebe
Takahiro
T
Aoyagi
Yasuyuki
Y
Kinoshita
Taira
T
Konishi
Masaru
M
Nakagohri
Toshio
T
Inoue
Kazuto
K
Takahashi
Shinichiro
S
Kawahira
Hiroshi
H
Monden
Morito
M
Ochiai
Atsushi
A
D000230:Adenocarcinoma / Q000473:pathology; D000328:Adult; D000368:Aged; D021441:Carcinoma, Pancreatic Ductal / Q000175:diagnosis / Q000473:pathology*; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007834:Lasers; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051901:Smad4 Protein; D013997:Time Factors; D015534:Trans-Activators / Q000096:biosynthesis*
D004268:DNA-Binding Proteins; D012333:RNA, Messenger; C497796:SMAD4 protein, human; D051901:Smad4 Protein; D015534:Trans-Activators