Patients from a hereditary nonpolyposis colorectal cancer (HNPCC) kindred (Lynch Type 1 and Type 2) have an increased risk of developing large-bowel cancer. Tumors occur at a young age and are characteristically right-sided. Colonic mucosal proliferation is known to be increased in several groups of patients at risk of colorectal cancer. PURPOSE: This study was performed to assess the pattern of mucosal proliferation at different sites in the colon of patients at risk of HNPCC and to determine whether this pattern differs from normal patients. METHODS: Mucosal biopsies were obtained at colonoscopy from 21 patients at risk for HNPCC (16 females; mean age, 42 years) and from 7 normal patients (4 females; mean age, 38 years), and mucosal proliferation was quantified using the whole crypt mitotic count (WCMC) technique. RESULTS: In patients from HNPCC families, WCMC and crypt area were significantly greater in the cecum than in the transverse colon and left colon (
P
< 0.001).="" compared="" with="" normal="" patients,="" wcmc="" in="" hnpcc="" patients="" was="" significantly="" greater="" in="" the="" cecum=""> (
P
< 0.05).="" a="" significant="" right-to-left="" shift="" was="" also="" observed="" in="" normal="" patients,="" but="" the="" percentage="" increase="" from="" right="" to="" left="" was="" two-fold="" greater="" in="" hnpcc="" patients.="" conclusions:="" these="" results="" confirm="" a="" proximalto-distal="" proliferative="" gradient="" in="" the="" human="" colon="" and="" suggest="" that="" this="" may="" be="" exaggerated="" in="" hnpcc.="" this="" increased="" proximal="" proliferative="" rate="" may="" be="" a="" factor="" in="" the="" development="" of="" right-sided="" cancer="" in="" these="">.
Key words
Hereditary nonpolyposis colorectal cancer
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Proliferation
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Mitotic count
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Colonic crypt
Supported by the Joint Research Board, St Bartholomew's Hospital, London, United Kingdom.
Presented in part at the meeting of The American Gastroenterological Association, Boston, Massachusetts, May 16 to 19, 1993.