Infiltrating adenocarcinomas of the pancreas are believed to arise from histologically identifiable intraductal precursors [pancreatic intraepithelial neoplasias (PanINs)] that undergo a series of architectural, cytological, and genetic changes. The role of DPC4 tumor suppressor gene inactivation in this progression has not been defined. Immunohistochemistry for the Dpc4 protein in formalin-fixed, paraffin-embedded tissue is a sensitive and specific marker for DPC4 gene status, providing a tool to examine DPC4 status in these putative precursor lesions. A total of 188 PanINs were identified in 40 pancreata, 38(95%) of which also contained an infiltrating adenocarcinoma. Sections containing these 188 duct lesions were labeled with a monoclonal antibody to Dpc4. All 82 flat (PanIN-1A), all 54 papillary (PanIN-1B),and all 23 atypical papillary (PanIN-2) intraductal lesions expressed Dpc4. In contrast, 9 of 29 (31%) severely atypical lesions (PanIN-3 lesions, carcinomas in situ) did not. The difference in Dpc4 expression between histologically low-grade (PanIN-1 and -2) and histologically high-grade (PanIN-3) duct lesions was statistically significant (P < 0.0001). In three cases, the pattern of Dpc4 expression in the PanIN-3 lesions did not match the pattern of expression in the associated infiltrating carcinomas, indicating that these high-grade lesions did not simply represent infiltrating carcinoma growing along benign ducts. Loss of Dpc4 expression occurs biologically late in the neoplastic progression that leads to the development of infiltrating pancreatic cancer, at the stage of histologically recognizable carcinoma.

Recent evidence suggests that, in the pancreas, there is a neoplastic progression very similar to the adenoma-carcinoma sequence in the colon (1, 2, 3, 4). That is, in some pancreatic ducts and ductules, a mucinous epithelium with cytological and architectural atypia replaces the normal cuboidal epithelium. These duct lesions are also known as PanINs,3and they are believed to progress from flat to papillary without atypia to papillary with atypia to carcinoma in situ (PanIN-1A to PanIN-1B to PanIN-2 to PanIN-3; Refs. 3, 4, 5, 6, 7). Some in situ lesions then eventually progress to infiltrating adenocarcinoma. Thus, even those clinically “early” infiltrating pancreatic cancers are, in fact, biologically late (4).

Infiltrating pancreatic cancers that are clinically early are also genetically late. Most infiltrating pancreatic cancers have accumulated numerous genetic alterations by the time they come to clinical presentation (8). For example, Rozenblum et al.(8) found nine separate key genetic alterations in a single infiltrating pancreatic cancer. Not surprisingly, PanINs also show many of these same genetic changes. For example, we and others(9, 10, 11, 12, 13, 14, 15, 16, 17, 18) have identified K-ras, HER-2/neu, p16, BRCA2, and p53 alterations in a variety of PanINs using both genetic and immunohistochemical analyses. By doing so, we have been able to establish the presumed relative timing of these genetic alterations in the pancreatic cancer progression model (see Table 1 for a literature review of gene alterations in PanINs).

Whereas alterations in these five genes have been studied in PanINs,inactivation of the DPC4 tumor suppressor gene has not. DPC4 is one of the major tumor suppressor genes targeted in infiltrating pancreatic adenocarcinoma. It is inactivated in over half of invasive pancreatic adenocarcinomas, and its inactivation is relatively specific for invasive pancreatic adenocarcinoma(19, 20, 21). That is, whereas many cancer types harbor alterations in the K-ras, p16, BRCA2,and p53 genes, inactivation of DPC4 occurs only infrequently in nonpancreatic cancers (19, 20, 21, 22, 23, 24, 25, 26).

Therefore, we examined the expression of the Dpc4 protein in a spectrum of PanINs. We have recently shown that immunohistochemistry for Dpc4 is an extremely sensitive and specific marker for DPC4 gene inactivation, independent of whether inactivation occurs by homozygous deletion (deletion of both alleles of the DPC4 gene) or by mutation in one allele coupled with loss of the other allele (loss of heterozygosity; Ref. 17). Determining the patterns of Dpc4 expression in a large number of histologically defined PanINs will help to establish the role of DPC4 inactivation in the development of pancreatic neoplasia.

Specimen Selection.

Pancreaticoduodenectomy specimens (Whipple resection specimens) from 40 patients were studied. Thirty-eight resections (95%) were performed for infiltrating adenocarcinoma, and two resections were performed for chronic pancreatitis. These resections fell into two groups:(a) 31 resections were originally selected for the study because the infiltrating adenocarcinoma in each of them had been previously analyzed genetically for DPC4 gene mutations and analyzed immunohistochemically for Dpc4 expression (17, 19, 20, 21); and (b) 9 pancreata were added to the analyses because they contained well-defined, severely atypical intraductal neoplasias (PanIN-3 lesions, carcinomas in situ).

Identification of Duct Lesions.

Multiple H&E-stained slides of pancreatic tissue from each of the cases were screened by light microscopy for PanINs. Criteria established at a National Cancer Institute-sponsored Pancreas Cancer Think Tank in September, 1999, in Park City, Utah were used to classify each lesion(3, 5, 6, 7, 27, 28, 29).4Unstained 5-μm sections containing the PanINs were then cut from paraffin blocks for immunohistochemical analysis.

Immunohistochemistry.

Unstained sections were treated with a monoclonal antibody (clone B8;Santa Cruz Biotechnology, Santa Cruz, CA; 1:100 dilution) to Dpc4 under previously described conditions (17). Briefly, each slide was deparaffinzed by routine techniques, treated with sodium citrate buffer (diluted to 1× HIER buffer from 10× HIER buffer; Ventana-Bio Tek Solutions, Tucson, AZ), and steamed for 20 min at 80°C. After cooling for 5 min, the slides were labeled with the antibody using the Bio Tek-Mate 1000 automated stainer (Ventana-Bio Tek Solutions). The anti-Dpc4 antibody was detected by adding biotinylated secondary antibodies, avidin-biotin complex, and 3,3′-diaminobenzidine. Sections were counterstained with hematoxylin. For negative controls, the primary antibody was replaced with normal saline.

Immunohistochemical Interpretation.

Two of the authors of this study (R. E. W. and R. H. H.)independently evaluated the immunohistochemical labeling of each PanIN,without knowledge of the gene status or expression phenotype of the associated infiltrating adenocarcinoma. The labeling of each lesion was scored as “positive,” “weakly positive,” or “negative” as described previously (17). Positive labeling was defined as strong and uniform expression of Dpc4 in the cytoplasm of the majority of cells, with focal expression of Dpc4 in nuclei. Weakly positive PanINs showed weak expression of Dpc4 in the cytoplasm of the majority of cells, with or without expression of Dpc4 in nuclei. Cases were regarded as negative only when no expression of Dpc4 was seen in the cytoplasmic or nuclear compartments of cells. Positive and weakly positive cases were grouped together as positive for subsequent analysis.

The interpretation of immunohistochemical labeling of the lesions was highly robust, with agreement between the observers in 185 of the 188(98%) PanINs. Two of the three discordant cases were called positive by one author and weakly positive by the other. The third PanIN was interpreted as weakly positive by one author and as negative by the other. Re-examination of these cases by both authors together resulted in agreement that the former PanINs were weakly positive and that the latter was negative.

Normal pancreatic ducts, islets of Langerhans, acini, lymphocytes, and stromal fibroblasts, all of which show moderate to strong expression of the DPC4 gene product, served as positive internal controls in each of the sections.

Statistical Analysis.

The presence of Dpc4 expression in PanINs was analyzed with two-tailed Fisher’s exact tests. Tests were performed using Statistica for Windows (StatSoft, Tulsa, OK).

Associated Infiltrating Adenocarcinomas.

Thirty-one of the 40 resections included in this study contained infiltrating adenocarcinomas previously analyzed genetically for DPC4 mutations and immunohistochemically for Dpc4 expression(17, 19, 20, 21). Of these 31 infiltrating adenocarcinomas, 25 were conventional ductal adenocarcinomas of the pancreas, 1 was a poorly differentiated adenocarcinoma of the pancreas with clear cell features, 4 were adenocarcinomas of the distal common bile duct, and 1 was an adenocarcinoma of the papilla (ampulla) of Vater.

This group of 31 cancers included 20 infiltrating cancers with inactivated DPC4 genes and 11 cancers with at least one wild-type DPC4 allele. Of the 20 cancers with inactivated genes, 19 had homozygously deleted genes, and 1 had a mutant allele coupled with loss of the other allele (loss of heterozygosity). As reported previously (17), all 11 of the infiltrating cancers with wild-type alleles showed Dpc4 expression by immunohistochemistry. Eighteen of the 19 (95%) infiltrating cancers with homozygously deleted genes did not express Dpc4, and the one cancer with a mutant allele coupled with loss of heterozygosity also did not express Dpc4. Therefore, our previous study showed that immunohistochemistry detects inactivation of the DPC4 gene,regardless of the mechanism of inactivation (17).

Nine pancreata were added to the study because they harbored well-defined PanIN-3 lesions; seven (78%) of these also had separate areas of infiltrating adenocarcinoma. Six (86%) of the infiltrating cancers were conventional ductal adenocarcinomas of the pancreas, and one was an adenocarcinoma of the distal common bile duct. Four of these seven (57%) infiltrating cancers, including the one originating in the common bile duct, expressed the Dpc4 protein. The two pancreata with only chronic pancreatitis had been entirely submitted for histological examination to rule out foci of invasive cancer.

Thus, 38 of the 40 (95%) pancreata included in this study harbored an infiltrating adenocarcinoma, and 22 of these 38 (58%) infiltrating cancers showed loss of Dpc4 expression.

PanINs.

A total of 188 PanINs were identified in the 40 pancreata included in this study. Overall, 179 (95%) of these PanINs expressed Dpc4. All 82 PanIN-1As, all 54 PanIN-1Bs (Figs. 1 and 2), and all 23 PanIN-2s expressed Dpc4 (Table 2). In contrast, Dpc4 expression was found in 20 of the 29 (69%)PanIN-3s (Figs. 1 and 2). The difference in Dpc4 expression between“early” (PanIN-1A, PanIN-1B, and PanIN-2) and “advanced”(PanIN-3) duct lesions was statistically significant(P < 0.0001).

There was no progressive weakening in intensity of Dpc4 expression from early PanINs to advanced PanINs to invasive carcinomas. Whereas both strongly and weakly positive cases were indeed grouped together for analysis, it is important to note that the overwhelming majority of PanINs that express Dpc4 do so strongly. For example, 52 of the 52(100%) PanIN-1As, 50 of the 54 (93%) PanIN-1Bs, and 22 of the 23(96%) PanIN-2s included in this study labeled strongly for Dpc4. In addition, of the 20 PanIN-3s that expressed Dpc4, 18 (90%) did so strongly. Finally, a previous study on Dpc4 expression in infiltrating carcinomas revealed that 17 of 19 (90%) infiltrating carcinomas expressing Dpc4 labeled strongly with our technique (17).

Evaluation of Dpc4 Expression in PanIN-3s (Carcinomas in Situ).

Twenty-nine PanIN-3s were identified in 12 pancreata (see Table 3). Twenty (69%) of these lesions expressed Dpc4, and nine (31%) did not. The 20 PanIN-3s that expressed Dpc4 were from eight different patients. The eight resections included the following: (a)three with associated infiltrating pancreatic ductal adenocarcinomas that expressed Dpc4; (b) two with associated infiltrating pancreatic ductal adenocarcinomas that did not express Dpc4;(c) one with an associated infiltrating pancreatic ductal adenocarcinoma that focally expressed Dpc4; (d) one with an associated infiltrating distal common bile duct adenocarcinoma that expressed Dpc4; and (e) one without an infiltrating carcinoma.

Nine of the 29 (31%) PanIN-3s did not express Dpc4, and these originated in four patients. Within these four pancreata, 11 PanIN-1As,3 PanIN-1Bs, and 2 PanIN-2s, all expressing Dpc4, were also identified. These four resections included the following: (a) two with associated infiltrating pancreatic ductal adenocarcinomas that did not express Dpc4; (b) one with an associated infiltrating distal common bile duct adenocarcinoma that expressed Dpc4; and (c)one without an infiltrating carcinoma. Table 3 summarizes the results from all of the cases containing at least one PanIN-3.

Thus, in two cases with PanIN-3, there was no associated infiltrating cancer. In 7 of the 10 (70%) remaining cases, the pattern of Dpc4 expression in the PanIN-3s matched the pattern of Dpc4 expression in the associated infiltrating carcinomas. In contrast, in three cases,the pattern of labeling in the PanIN-3s did not match that in the associated infiltrating cancers. These findings demonstrate that these PanIN-3s were not simply an artifact of an infiltrating carcinoma extending along preexisting benign ducts.

Pancreatic adenocarcinoma is a genetic disease. For example,approximately 55% of pancreatic adenocarcinomas show inactivation of the DPC4 gene (17, 19, 20, 21). Homozygous deletion(deletion of both alleles) inactivates DPC4 in 35% of pancreatic adenocarcinomas, and intragenic mutation in one allele coupled with loss of the second allele (loss of heterozygosity)inactivates it in another 20% of pancreatic adenocarcinomas(19, 20, 21).

Genetic changes are also seen in PanINs, the putative precursors of infiltrating duct adenocarcinoma of the pancreas (9, 10, 11). These precursors can show a spectrum of architectural and cellular changes. They can be flat (PanIN-1A), papillary (PanIN-1B), papillary with moderate atypia (PanIN-2), or severely atypical (PanIN-3,carcinoma in situ; Refs. 3, 4, 5, 7, and27, 28, 29; see Fig. 3). Alterations in the sequences or expression levels of the K-ras, HER-2/neu, p16, BRCA2, and p53 genes have already been detected in PanINs, and the prevalence of these mutations increases with increasing grade of the PanIN (Refs. 9, 10, 11, 12, 13, 14, 15, 16, 17, 18; see Table 1). If we assume that the higher-grade PanINs represent more advanced lesions than the lower-grade PanINs, then these data help establish the relative timing of genetic alterations in the progression model of pancreatic adenocarcinoma.

Whereas the prevalence of alterations in these five genes has been studied in various grades of PanIN, the prevalence of DPC4alterations has not. We therefore examined the expression of the Dpc4 protein in a spectrum of PanINs. We chose this indirect immunohistochemical method because we have previously shown that immunohistochemistry for Dpc4 is an extremely sensitive and specific marker for DPC4 gene status (17).

A total of 188 PanINs were identified in the 40 pancreata included in this study. All (100%) of the PanIN-1As, PanIN-1Bs, and PanIN-2s expressed Dpc4. In contrast, approximately one-third of the PanIN-3s(severely atypical duct lesions, carcinomas in situ) lost Dpc4 expression. The difference in Dpc4 expression between the former and the latter was statistically significant (P < 0.0001).

These data lead to several striking conclusions. First, and most obviously, inactivation of the DPC4 gene occurs late in the development of pancreatic adenocarcinoma, at the stage of in situ or even invasive carcinoma. That is, loss of Dpc4 is synonymous with the onset of carcinomatous change. This fact has important implications for tumor biology because it shows that dramatic biological alterations may be strongly associated with the loss of a particular gene. Our findings also should stimulate the creation of experimental models that investigate the molecular basis of the transition between “benign” and “malignant,” similar to DPC4-APC compound mutant mice that have already been developed (30).

Second, because inactivation of DPC4 occurs late in the progression of pancreatic adenocarcinoma, immunohistochemistry for Dpc4 may be useful as a clinical marker for pancreatic carcinoma. The loss of Dpc4 expression appears to be very specific for highly advanced neoplasia/carcinoma. Conversely, however, because only 55% of invasive pancreatic adenocarcinomas show inactivation of the DPC4gene, the presence of intact Dpc4 cannot be used to indicate that a lesion is benign.

Third, these data help establish that the lesions we have designated as PanIN-3s do not simply represent a “cancerization of benign ducts.”In three of the cases we examined, the pattern of Dpc4 expression in the PanIN-3s (carcinomas in situ) did not match the pattern of Dpc4 expression in the associated infiltrating adenocarcinomas, and in two additional cases, an infiltrating carcinoma was not present. Therefore, these PanIN-3s (carcinomas in situ) could not simply be a manifestation of infiltrating cancer growing along preexisting ducts. While cancerization of benign ducts does occur within the pancreas, our data show that malignant-appearing cells within a duct do not always reflect such a process. Instead, PanIN-3s may represent lesions independent from an associated infiltrating carcinoma. In addition, the case with a Dpc4-positive biliary carcinoma and a Dpc4-negative PanIN-3 suggests that although pancreatic and biliary neoplasia can occur together, they may be genetically distinct.

Finally, these data and previous data allow us to begin to construct a genetic model of pancreatic cancer progression (Table 1; Fig. 3). K-ras mutations and HER-2/neu overexpression are the earliest changes in the progression model (9, 12, 13, 14, 15, 18). Alterations in p16 occur at different histological stages but are found primarily in PanIN-2s and PanIN-3s (9, 10). DPC4, BRCA2, and p53 appear to be inactivated very late in the progression model (11, 16, 31).

Clearly, this progression model of pancreatic neoplasia is still under construction. More genes may be identified, and as greater numbers of cases are examined, the timing of the known alterations may be more accurately determined. Nevertheless, it is clear that DPC4genetic alterations are important in the progression to carcinoma and that immunohistochemistry provides an indirect but effective and convenient means to determine DPC4 expression in a large number of cases.

We thank Jennifer A. Galford for her hard work in preparing the manuscript and Josephine Geh for her expertise in performing the immunohistochemical assays.

The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

      
1

Supported in part by the NIH Specialized Program of Research Excellence in Gastrointestinal Cancer CA62924, by USPHS Grant CA67751-03, and by generous donations from the Helen S. Heller and Daniel Kim Memorial Funds for Pancreatic Cancer Research.

            
3

The abbreviation used is: PanIN, pancreatic intraepithelial neoplasia.

      
4

http://pathology.jhu.edu/pancreas_panin

Table 1

Review of gene alterations in normal pancreatic ducts,(PanINs)a, and infiltrating pancreatic ductal adenocarcinomas

Gene (reference no.)NormalPanIN-1APanIN-1BPanIN-2PanIN-3Infiltrating
HER-2/neu (12) 5% 82% 86% 92% 100% 69% 
K-ras (9, 13–15, 18, 32, 33) 0–15%b 35% 43% c 86% ∼90% 
p16 (9, 10, 34, 35) 0% 24% 19% 55% 71% ∼95% 
p53 (11, 16, 36) 0% 0% 0% d 21% ∼75% 
DPC4 (17, 19, this study) 0% 0% 0% 0% 31% ∼55% 
BRCA2 (31, 37)e 0% 0% 0% 0% F 7% 
Gene (reference no.)NormalPanIN-1APanIN-1BPanIN-2PanIN-3Infiltrating
HER-2/neu (12) 5% 82% 86% 92% 100% 69% 
K-ras (9, 13–15, 18, 32, 33) 0–15%b 35% 43% c 86% ∼90% 
p16 (9, 10, 34, 35) 0% 24% 19% 55% 71% ∼95% 
p53 (11, 16, 36) 0% 0% 0% d 21% ∼75% 
DPC4 (17, 19, this study) 0% 0% 0% 0% 31% ∼55% 
BRCA2 (31, 37)e 0% 0% 0% 0% F 7% 
a

Histologic classification of PanINs is given in the text.

b

Authors are not in agreement that normal ductal epithelium harbors K-ras mutations.

c

Insufficient numbers of PanIN-2 were present in these studies to present an accurate result.

d

One PanIN-2 identified by Hameed et al.(16) overexpressed p53, but the total number of PanINs-2 was not reported. Therefore, a percentage could not be calculated.

e

BRCA2 data in PanINs are restricted to patients with germ-line BRCA2 inactivating mutations.

f

Only one PanIN-3 was studied by Goggins et al.,(31) and it showed a BRCA2 germ-line mutation coupled with loss of heterozygosity.

Fig. 1.

A, a PanIN-1B expresses the Dpc4 protein in both the cytoplasmic and nuclear compartments. All PanIN-1Bs in this study expressed the Dpc4 protein. B, a PanIN-3 has strong and uniform expression of the Dpc4 protein.

Fig. 1.

A, a PanIN-1B expresses the Dpc4 protein in both the cytoplasmic and nuclear compartments. All PanIN-1Bs in this study expressed the Dpc4 protein. B, a PanIN-3 has strong and uniform expression of the Dpc4 protein.

Close modal
Fig. 2.

A, a PanIN-1B (right) and a PanIN-3 (left) from the same pancreas. The PanIN-1B expresses Dpc4, but the PanIN-3 does not. B, higher power view of the PanIN-1B. C, higher power view of the PanIN-3.

Fig. 2.

A, a PanIN-1B (right) and a PanIN-3 (left) from the same pancreas. The PanIN-1B expresses Dpc4, but the PanIN-3 does not. B, higher power view of the PanIN-1B. C, higher power view of the PanIN-3.

Close modal
Table 2

Dpc4 expression in subtypes of PanINsa

ExpressionPanIN-1APanIN-1BPanIN-2PanIN-3Total
Positive 82 54 23 20 179 
Negative 
Total 82 54 23 29 188 
ExpressionPanIN-1APanIN-1BPanIN-2PanIN-3Total
Positive 82 54 23 20 179 
Negative 
Total 82 54 23 29 188 
a

Histological classification and immunohistochemical interpretations are given in the text. P < 0.0001 (PanIN-1 and 2 versus PanIN-3, Fisher’s exact test).

Table 3

Catalogue of cases with PanIN-3a

CaseNo. of PanINs-3 with Dpc4 expressionNo. of PanINs-3 without Dpc4 expressionAssociated invasive carcinomaDpc4 expression in associated invasive carcinomaOther PanINs identifiedb
Pancreaticc Present None 
Pancreatic Present None 
Pancreatic Present 1 PanIN-1B and 1 PanIN-2 
Pancreatic Absent None 
Pancreatic Absent None 
Pancreatic Focally present 2 PanIN-1As 
Bile ductd Present 2 PanIN-2s 
None NAe None 
Pancreatic Absent None 
10 Pancreatic Absent 8 PanIN-1As and 2 PanIN-2s 
11 Bile duct Present 3 PanIN-1As and 2 PanIN-1Bs 
12 None NA 1 PanIN-1B 
CaseNo. of PanINs-3 with Dpc4 expressionNo. of PanINs-3 without Dpc4 expressionAssociated invasive carcinomaDpc4 expression in associated invasive carcinomaOther PanINs identifiedb
Pancreaticc Present None 
Pancreatic Present None 
Pancreatic Present 1 PanIN-1B and 1 PanIN-2 
Pancreatic Absent None 
Pancreatic Absent None 
Pancreatic Focally present 2 PanIN-1As 
Bile ductd Present 2 PanIN-2s 
None NAe None 
Pancreatic Absent None 
10 Pancreatic Absent 8 PanIN-1As and 2 PanIN-2s 
11 Bile duct Present 3 PanIN-1As and 2 PanIN-1Bs 
12 None NA 1 PanIN-1B 
a

Histological classification of PanINs is given in the text.

b

All of the PanIN-1As,-1Bs, and -2s expressed Dpc4.

c

“Pancreatic” refers to ductal adenocarcinomas originating within the pancreas.

d

“Bile duct” refers to adenocarcinomas arising within the distal common bile duct.

e

NA, not applicable.

Fig. 3.

Progression model for duct adenocarcinoma of the pancreas. It is hypothesized that a duct lesion can progress from a histologically normal duct to flat duct lesion(PanIN-1A) to papillary duct lesion(PanIN-1B) to atypical papillary duct lesion(PanIN-2) to severely atypical duct lesion/carcinoma in situ (PanIN-3). The approximate timing of alterations in the K-ras, HER-2/neu, p16, p53, BRCA2, and DPC4 genes is indicated on the model (see also Table 1;artwork by Jennifer L. Parsons).

Fig. 3.

Progression model for duct adenocarcinoma of the pancreas. It is hypothesized that a duct lesion can progress from a histologically normal duct to flat duct lesion(PanIN-1A) to papillary duct lesion(PanIN-1B) to atypical papillary duct lesion(PanIN-2) to severely atypical duct lesion/carcinoma in situ (PanIN-3). The approximate timing of alterations in the K-ras, HER-2/neu, p16, p53, BRCA2, and DPC4 genes is indicated on the model (see also Table 1;artwork by Jennifer L. Parsons).

Close modal
1
Vogelstein B., Kinzler K. W. The multistep nature of cancer.
Trends Genet.
,
9
:
138
-141,  
1993
.
2
Fearon E. R., Vogelstein B. A genetic model for colorectal tumorigenesis.
Cell
,
61
:
759
-767,  
1990
.
3
Homology to pancreatic ribonucleasesHruban, R. H., and Wilentz, R. E. Pancreas. In: N. Weidner, R. J. Cote, S. Suster, and L. M. Weiss (eds.), Modern Surgical Pathology. Philadelphia: W. B. Saunders Co., in press, 2000.
4
Brat D. J., Lillemoe K. D., Yeo C. J., Warfield P. B., Hruban R. H. Progression of pancreatic intraductal neoplasias (high-grade PanIN) to infiltrating adenocarcinoma of the pancreas.
Am. J. Surg. Pathol.
,
22
:
163
-169,  
1998
.
5
Kozuka S., Sassa R., Taki T., Masamoto K., Nagasawa S., Saga S., Hasegawa K., Takeuchi M. Relation of pancreatic duct hyperplasia to carcinoma.
Cancer (Phila.)
,
43
:
1418
-1428,  
1979
.
6
Pour P. M., Sayed S., Sayed G. Hyperplastic, preneoplastic and neoplastic lesions found in 83 human pancreases.
Am. J. Clin. Pathol.
,
77
:
137
-152,  
1982
.
7
Furukawa T., Chiba R., Kobari M., Matsuno S., Nagura H., Takahashi T. Varying grades of epithelial atypia in the pancreatic ducts of humans.
Classification based on morphometry and multivariate analysis and correlated with positive reactions of carcinoembryonic antigen. Arch. Pathol. Lab. Med.
,
118
:
227
-234,  
1994
.
8
Rozenblum E., Schutte M., Goggins M., Hahn S. A., Panzer S., Zahurak M., Goodman S. N., Sohn T. A., Hruban R. H., Yeo C. J., Kern S. E. Tumor-suppressive pathways in pancreatic carcinoma.
Cancer Res.
,
57
:
1731
-1734,  
1997
.
9
Moskaluk C. A., Hruban R. H., Kern S. E. p16 and K-ras gene mutations in the intraductal precursors of human pancreatic adenocarcinoma.
Cancer Res.
,
57
:
2140
-2143,  
1997
.
10
Wilentz R. E., Geradts J., Maynard R., Offerhaus G. J. A., Kang M., Goggins M., Yeo C. J., Kern S. E., Hruban R. H. Inactivation of the p16 (INK4A) tumor-suppressor gene in pancreatic duct lesions: loss of intranuclear expression.
Cancer Res.
,
58
:
4740
-4744,  
1998
.
11
DiGiuseppe J. A., Hruban R. H., Goodman S. N., Polak M., van den Berg F. M., Allison D. C., Cameron J. L., Offerhaus G. J. A. Overexpression of p53 protein in adenocarcinoma of the pancreas.
Am. J. Clin. Pathol.
,
101
:
684
-688,  
1994
.
12
Day J. D., DiGiuseppe J. A., Yeo C. J., Loi-Goldman M., Anderson S., Kern S. E., Hruban R. H. Immunohistochemical evaluation of HER-2/neu oncogene expression in pancreatic adenocarcinoma and pancreatic intraepithelial neoplasms.
Hum. Pathol.
,
27
:
119
-124,  
1996
.
13
Yanagisawa A., Ohtake K., Ohashi K., Hori M., Kitagawa T., Sugano H., Kato Y. Frequent c-Ki-ras oncogene activation in mucous cell hyperplasias of pancreas suffering from chronic inflammation.
Cancer Res.
,
53
:
953
-956,  
1993
.
14
Tada M., Ohashi M., Shiratori Y., Okudaira T., Komatsu Y., Kawabe T., Yoshida H., Machinami R., Kishi K., Omata M. Analysis of K-ras gene mutation in hyperplastic duct cells of the pancreas without pancreatic disease.
Gastroenterology
,
110
:
227
-231,  
1996
.
15
Caldas C., Hahn S. A., Hruban R. H., Redston M. S., Yeo C. J., Kern S. E. Detection of K-ras mutations in the stool of patients with pancreatic adenocarcinoma and pancreatic ductal hyperplasia.
Cancer Res.
,
54
:
3568
-3573,  
1994
.
16
Hameed M., Marrero A. M., Conlon K. C., Brennan M. F., Klimstra D. S. Expression of p53 nucleophosphoprotein in in situ pancreatic ductal adenocarcinoma: an immunohistochemical analysis of 100 cases.
Lab. Investig.
,
70
:
132A
1994
.
17
Wilentz R. E., Su G. H., Dai J. L., Sparks A. B., Argani P., Sohn T. A., Yeo C. J., Kern S. E., Hruban R. H. Immunohistochemistry labeling for Dpc4 mirrors genetic status in pancreatic and peripancreatic adenocarcinomas: a new marker of DPC4 inactivation.
Am. J. Pathol.
,
156
:
37
-43,  
2000
.
18
Lüttges J., Schlehe B., Menke M. A., Vogel I., Henne-Bruns D., Klöppel G. The K-ras mutation pattern in pancreatic ductal adenocarcinoma usually is identical to that in associated normal, hyperplastic, and metaplastic ductal epithelium.
Cancer (Phila.)
,
85
:
1703
-1710,  
1999
.
19
Hahn S. A., Schutte M., Hoque A. T. M. S., Moskaluk C. A., daCosta L. T., Rozenblum E., Weinstein C. L., Fischer A., Yeo C. J., Hruban R. H., Kern S. E. DPC4, a candidate tumor suppressor gene at human chromosome 18q21.1.
Science (Washington DC)
,
271
:
350
-353,  
1996
.
20
Hahn S. A., Hoque A. T. M. S., Moskaluk C. A., daCosta L. T., Schutte M., Rozenblum E., Seymour A., Weinstein C. L., Yeo C. J., Hruban R. H., Kern S. E. Homozygous deletion map at 18q21.1 in pancreatic cancer.
Cancer Res.
,
56
:
490
-494,  
1996
.
21
Schutte M., Hruban R. H., Hedrick L., Cho K. R., Nadasdy G. M., Weinstein C. L., Bova G. S., Isaacs W. B., Cairns P., Nawroz H., Sidransky D., Casero R. A., Meltzer P. S., Hahn S. A., Kern S. E. DPC4 gene in various tumor types.
Cancer Res.
,
56
:
2527
-2530,  
1996
.
22
Hoque A. T., Hahn S. A., Schutte M., Kern S. E. DPC4 gene mutation in colitis associated neoplasia.
Gut
,
40
:
120
-122,  
1997
.
23
Hahn S. A., Bartsch D., Schroers A., Galehdari H., Becker M., Ramaswamy A., Schwarte-Waldhoff I., Maschek H., Schmiegel W. Mutations of the DPC4/Smad4 gene in biliary tract carcinoma.
Cancer Res.
,
58
:
1124
-1126,  
1998
.
24
Bartsch D., Hahn S. A., Danichevski K. D., Ramaswamy A., Bastian D., Galehdari H., Barth P., Schmiegel W., Simon B., Rothmund M. Mutations of the DPC4/Smad4 gene in neuroendocrine pancreatic tumors.
Oncogene
,
18
:
2367
-2371,  
1999
.
25
Thiagalingam S., Lengauer C., Leach F. S., Schutte M., Hahn S. A., Overhauser J., Willson J. K., Markowitz S., Hamilton S. R., Kern S. E., Kinzler K. W., Vogelstein B. Evaluation of candidate tumor suppressor genes on chromosome 18 in colorectal cancers.
Nat. Genet.
,
13
:
343
-346,  
1996
.
26
Takagi Y., Kohmura H., Futamura M., Kida H., Tanemura H., Shimokawa K., Saji S. Somatic alterations of the DPC4 gene in human colorectal cancers in vivo.
Gastroenterology
,
111
:
1369
-1372,  
1996
.
27
DiGiuseppe J. A., Yeo C. J., Hruban R. H. Molecular biology and the diagnosis and treatment of adenocarcinoma of the pancreas.
Adv. Anat. Pathol.
,
3
:
139
-155,  
1996
.
28
Hruban R. H., DiGiuseppe J. A. K-ras mutations in pancreatic ductal proliferative lesions: author’s reply.
Am. J. Pathol.
,
145
:
1548
-1550,  
1994
.
29
Wilentz R. E., Hruban R. H. Pathology of cancer of the pancreas.
Surg. Oncol. Clin. N. Am.
,
7
:
43
-65,  
1998
.
30
Takaku K., Oshima M., Miyoshi H., Matsui M., Seldin M. F., Taketo M. M. Intestinal tumorigenesis in compound mutant mice of both Dpc4 (Smad4) and Apc genes.
Cell
,
92
:
645
-656,  
1998
.
31
Goggins, M., Hruban, R. H., and Kern, S. E. Relationship of BRCA2 germline mutation and pancreatic cancer intra-ductal lesions. Am. J. Pathol., in press, 2000.
32
Terhune P. G., Phifer D. M., Tosteson T. D., Longnecker D. S. K-ras mutation in focal proliferative lesions of human pancreas.
Cancer Epidemiol. Biomark. Prev.
,
7
:
515
-521,  
1998
.
33
Hruban R. H., van Mansfeld A. D. M., Offerhaus G. J. A., van Weering D. H. J., Allison D. C., Goodman S. N., Kensler T. W., Bose K. K., Cameron J. L., Bos J. L. K-ras oncogene activation in adenocarcinoma of the human pancreas.
A study of 82 carcinomas using a combination of mutant-enriched polymerase chain reaction analysis and allele-specific oligonucleotide hybridization. Am. J. Pathol.
,
143
:
545
-554,  
1993
.
34
Maynard R., Hruban R. H., Schutte M., Kern S. E., Geradts J. Immunohistochemical reactivity of mutant p16 proteins in paraffin sections: a comparison of four antibodies.
Mod. Pathol.
,
11
:
187A
1998
.
35
Schutte M., Hruban R. H., Geradts J., Maynard R., Hilgers W., Rabindran S. K., Moskaluk C. A., Hahn S. A., Schwarte-Waldhoff I., Schmiegel W., Baylin S. B., Kern S. E., Herman J. G. Abrogation of the Rb/p16 tumor-suppressive pathway in virtually all pancreatic carcinomas.
Cancer Res.
,
57
:
3126
-3130,  
1997
.
36
Redston M. S., Caldas C., Seymour A. B., Hruban R. H., da Costa L., Yeo C. J., Kern S. E. p53 mutations in pancreatic carcinoma and evidence of common involvement of homocopolymer tracts in DNA microdeletions.
Cancer Res.
,
54
:
3025
-3033,  
1994
.
37
Goggins M., Schutte M., Lu J., Moskaluk C. A., Weinstein C. L., Petersen G. M., Yeo C. J., Jackson C. E., Lynch H. T., Hruban R. H., Kern S. E. Germline BRCA2 gene mutations in patients with apparently sporadic pancreatic carcinomas.
Cancer Res.
,
56
:
5360
-5364,  
1996
.