1995 Fiscal Year Final Research Report Summary
The genetic changes of colorectal tumors on relation to histological grades of atypia
| Project/Area Number |
05671083
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Digestive surgery
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| Research Institution | JICHI MEDICAL SCHOOL |
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Principal Investigator |
KONISHI Fumio Jichi Medical School, Medical College Associate Professor, 医学部, 助教授 (20142242)
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| Co-Investigator(Kenkyū-buntansha) |
TSUCHIYA Issei Jichi Medical School, Medical College Instructor, 医学部, 助手 (90217331)
KASHIWAGI Hiroshi Jichi Medical School, Medical College Instructor, 医学部, 助手 (30204382)
YAMASHITA Keisuke Jichi Medical School, Medical College Lecturer, 医学部, 講師 (90239963)
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| Project Period (FY) |
1993 – 1995
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| Keywords | Colo rectal cancer / Adenoma-carcinoma sequence / De novo carcinogenesis / Ki-Ras gene / P-53 / Superficial type early colorectal cancer |
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| Research Abstract |
In order to analyze the pathways of carcinogenesis in the colon and rectum, we analyzed rates of Ki-ras codon 12 mutations and positive p53 immunostaining in 23 small polypoid type cancers, 20 superficial type cancers, both confined to the mucosa or to the submucosa, and 39 advenced cancers. The frequency of Ki-ras mutations in superficial type cancers was 10% (2/20), which was significantly lower than 43% (10/23) in small polypoid cancers and 38% (15/39) in advenced cancers. This data suggest that another pathway of colorectal carcinogenesis which does not involve Ki-ras point mutation might exist. In small polypoid type cancers, 2 out of the 10 showed mutation present only in the adenomatous areas but not in cancerous areas. This data suggest that cancer does not always develop from pre-existing adenoma with Ki-ras point mutation. Positive staining for the p53 protein of colorectal superficial cancers and small polypoid cancers was detected in 25% (5/20) and 35% (8/23) respectively. Positive staining for the p53 protein was detected only in carcinomatous ares and not in adenomatous areas. There was not distinction between superficial type cancers and small polypoid type cancers.
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