| Theme |
Up-to-date Therapuetic Strategy for Advanced Colorectal Cancer |
| Title |
Genetic Testing for High Risk Patient of Colorectal Cancer |
| Author |
Hideaki Itoh |
Department of Surgery I, University of Occupational and Environmental Health |
| Author |
Kohji Okamoto |
Department of Surgery I, University of Occupational and Environmental Health |
| Author |
Keiji Hirata |
Department of Surgery I, University of Occupational and Environmental Health |
| [ Summary ] |
Genetic testings for familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC), which are inherited in an autosomal dominant manner, have become more important tools and more reliable. Clinical diagnosis for FAP is not difficult when the patient has numerous colonic polyps, but genetic testing be necessary to diagnose patients who are very young and do not have many polyps in the large bowel. A germ line mutation of the APC-gene is well detected by using the PTT-method, taking patients' blood samples. Macroscopic findings of ordinary colorectal cancer HNPCC do not display many differences, but family history and age at time of development of colorectal cancer are different in the two diseases. To date, the only known cause is an inherited mutation in one of the following mismatch repair(MMR)genes: hMSH 2, hMLH 1, PMS 1, PMS 2 and hMSH 6. Because detection of these MMR gene mutations needs a great deal of work, the detection of the microsatellite instability of cancer tissues is useful as a genetic marker for HNPCC. Genetic testing for familial cancer should be performed, protecting patients' rights of privacy. Pre and post-test genetic counseling are the most important issues. |