Abstract
Conclusion: Our findings have implications for early diagnosis and for the identification of patients at increased risk. Background: Invasive cancers of the pancreas frequently are preceded by and associated with a spectrum of preneoplastic changes. We investigated the presence of K-ras mutations and allelic loss at 5q and 18q loci in preneoplastic lesions associated with nine cases of invasive pancreatic ductal carcinomas. Methods: We precisely microdissected 115 foci of normal, preinvasive, and invasive foci from paraffinembedded sections. Results: 1. K-ras mutations occur early in the pathogenesis of pancreatic adenocarcinoma. Mutations were identified in multiple preneoplastic foci associated with all six cases in which ras mutations were present in the corresponding invasive cancers, including nearly all foci of mucous cell and atypical hyperplasia, in some cases of papillary hyperplasia (40%), and in one example of morphologically normal epithelium. 2. Ras mutations in preneoplastic foci are widespread, occur distant from the invasive tumor, and may present multiple mutations. Two, and in one case three, different types of K-ras mutations were found in separate preneoplastic foci from three individual cases. 3. Evidence for a "second hit" in the ras gene (i.e., loss of wild-type allele or amplification of the mutant allele) was present in some tumors and may be associated with the invasive process. 4. In contrast to ras mutations, limited data suggest that loss of heterozygosity (LOH) at 5q and 18q are relatively late events.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 205-217 |
| Number of pages | 13 |
| Journal | International Journal of Gastrointestinal Cancer |
| Volume | 21 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jun 1997 |
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Keywords
- 18q
- 5q
- K-ras
- pancreatic cancer
- preneoplastic lesions
ASJC Scopus subject areas
- Oncology
- Gastroenterology
- Endocrinology
Cite this
K-ras mutations and allelic loss at 5q and 18q in the development of human pancreatic cancers. / Sugio, Kenji; Molberg, Kyle; Albores-Saavedra, Jorge; Virmani, Arvind K.; Kishimoto, Yosuke; Gazdar, Adi F.
In: International Journal of Gastrointestinal Cancer, Vol. 21, No. 3, 06.1997, p. 205-217.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - K-ras mutations and allelic loss at 5q and 18q in the development of human pancreatic cancers
AU - Sugio, Kenji
AU - Molberg, Kyle
AU - Albores-Saavedra, Jorge
AU - Virmani, Arvind K.
AU - Kishimoto, Yosuke
AU - Gazdar, Adi F.
PY - 1997/6
Y1 - 1997/6
N2 - Conclusion: Our findings have implications for early diagnosis and for the identification of patients at increased risk. Background: Invasive cancers of the pancreas frequently are preceded by and associated with a spectrum of preneoplastic changes. We investigated the presence of K-ras mutations and allelic loss at 5q and 18q loci in preneoplastic lesions associated with nine cases of invasive pancreatic ductal carcinomas. Methods: We precisely microdissected 115 foci of normal, preinvasive, and invasive foci from paraffinembedded sections. Results: 1. K-ras mutations occur early in the pathogenesis of pancreatic adenocarcinoma. Mutations were identified in multiple preneoplastic foci associated with all six cases in which ras mutations were present in the corresponding invasive cancers, including nearly all foci of mucous cell and atypical hyperplasia, in some cases of papillary hyperplasia (40%), and in one example of morphologically normal epithelium. 2. Ras mutations in preneoplastic foci are widespread, occur distant from the invasive tumor, and may present multiple mutations. Two, and in one case three, different types of K-ras mutations were found in separate preneoplastic foci from three individual cases. 3. Evidence for a "second hit" in the ras gene (i.e., loss of wild-type allele or amplification of the mutant allele) was present in some tumors and may be associated with the invasive process. 4. In contrast to ras mutations, limited data suggest that loss of heterozygosity (LOH) at 5q and 18q are relatively late events.
AB - Conclusion: Our findings have implications for early diagnosis and for the identification of patients at increased risk. Background: Invasive cancers of the pancreas frequently are preceded by and associated with a spectrum of preneoplastic changes. We investigated the presence of K-ras mutations and allelic loss at 5q and 18q loci in preneoplastic lesions associated with nine cases of invasive pancreatic ductal carcinomas. Methods: We precisely microdissected 115 foci of normal, preinvasive, and invasive foci from paraffinembedded sections. Results: 1. K-ras mutations occur early in the pathogenesis of pancreatic adenocarcinoma. Mutations were identified in multiple preneoplastic foci associated with all six cases in which ras mutations were present in the corresponding invasive cancers, including nearly all foci of mucous cell and atypical hyperplasia, in some cases of papillary hyperplasia (40%), and in one example of morphologically normal epithelium. 2. Ras mutations in preneoplastic foci are widespread, occur distant from the invasive tumor, and may present multiple mutations. Two, and in one case three, different types of K-ras mutations were found in separate preneoplastic foci from three individual cases. 3. Evidence for a "second hit" in the ras gene (i.e., loss of wild-type allele or amplification of the mutant allele) was present in some tumors and may be associated with the invasive process. 4. In contrast to ras mutations, limited data suggest that loss of heterozygosity (LOH) at 5q and 18q are relatively late events.
KW - 18q
KW - 5q
KW - K-ras
KW - pancreatic cancer
KW - preneoplastic lesions
UR - http://www.scopus.com/inward/record.url?scp=0030856052&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030856052&partnerID=8YFLogxK
U2 - 10.1007/BF02821606
DO - 10.1007/BF02821606
M3 - Article
C2 - 9322119
AN - SCOPUS:0030856052
VL - 21
SP - 205
EP - 217
JO - Journal of Gastrointestinal Cancer
JF - Journal of Gastrointestinal Cancer
SN - 1941-6628
IS - 3
ER -