Evaluation of epithelial cell proliferation rate in normal-appearing colonic mucosa as a high-risk marker for colorectal cancer.

To determine whether the colonic epithelial proliferation rate is useful as a marker for colorectal cancer, we measured the Ki-67 labeling index (LI) in normal-appearing mucosa from the sigmoid and ascending colon in patients with two or more tumors (early cancers, which are defined as tumors the depth of invasion of which is limited to mucosal layer or submucosal layer, adenomas, or both). The association of baseline LI with the risk of development of colon tumors 2 years after endoscopic removal was assessed by cohort analysis. The presence of two or more tumors was defined as occurrence. One hundred and six specimens from the sigmoid colon and 130 from the ascending colon from 246 subjects (203 males and 43 females) were used for analysis. The patients with higher upper-third LI in the normal-appearing mucosa in the sigmoid colon, but not in the ascending colon, had significantly more tumors at follow-up colonoscopy 2 years later (risk ratio, 3.6; 95% confidence interval, 1.2-10.6). Moreover, multivariate analysis showed that it was an independent factor. We concluded that the higher upper-third Ki-67 LI of normal-appearing mucosa in the sigmoid colon indicates a high risk for colorectal cancer.

Measurement of carcinoembryonic antigen in colonic effluent as a high-risk marker for colorectal carcinoma.

We evaluated the usefulness of carcinoembryonic antigen (CEA) concentrations in colonic effluent as a high-risk marker for colorectal carcinoma (CRC). After 213 patients ingested 1,800 ml of a 5% isotonic solution of magnesium citrate, colonic effluent was collected from them before routine colonoscopy from February through June 1992. Of these patients, 27 who had undergone colonoscopy after a mean of 2.6 years were selected as subjects. The relationship between the CEA concentration in the colonic effluent and the occurrence of new colorectal tumors was examined. The CEA concentration in colonic effluent was adjusted on the basis of alkaline phosphatase activity. New colorectal tumors were noted significantly more frequently (P = .006) in patients with a high CEA level in colonic effluent (5 of 5; 100%) than in those with low a CEA level (6 of 22; 27%). The CEA concentration in colonic effluent is a simple and practical biomarker for identification of patients at high risk for CRC.

Effects of the administration of wheat bran biscuit: changes in the diet.

We developed hard biscuit containing 30% wheat bran (WB biscuit) and administered it to 12 volunteers at 7.5 g/day (7.5 g group) or 15 g/day (15 g group) as wheat bran for 12 weeks. After 12 weeks, the dietary fiber intake from foods other than wheat bran decreased slightly in the both groups, in the 15 g group was the decrease notable especially, after the beginning of WB biscuit administration. We suggest that a closest attention to changes in dietary habit associated with intervention is needed in intervention studies using patients leading a normal life.

Three cases with familial adenomatous polyposis diagnosed as having malignant lesions in the course of a long-term trial using docosahexanoic acid (DHA)-concentrated fish oil capsules.

The inhibitory effect of n-3 polyunsaturated fatty acids on human colorectal cancer has been speculated on from epidemiological data and animal studies. We conducted a long-term trial of docosahexanoic acid (DHA)-concentrated fish oil capsules for patients in a high-risk group for colorectal cancer. During this trial, we experienced three patients with familial adenomatous polyposis (FAP) diagnosed as having malignant lesions. Three patients with FAP and two patients with multiple (more than 30) colorectal polyps were administered DHA-concentrated fish oil capsules_Hlk427554600[2.2 g of DHA and 0.6 g of eicosapentanoic acid (EPA) per day] for one or two years. Compliance with DHA-concentrated fish oil capsules was more than 90% in four patients and 61% in one patient. A marked increase or decrease in the number of polyps was not observed. Three patients with FAP developed endometrial cancer after 12 months, colon cancer after 24 months and lung cancer after 12 months, respectively. All cancers were diagnosed at an early stage and were resected curatively. We thought that the possibility of developing cancer from the long-term administration of fish oil capsules to patients with FAP needs to be investigated further, and that we should report these cases.

Interventional trial for colorectal cancer prevention in Osaka: an introduction to the protocol.

We established a protocol for an interventional randomized controlled trial for prevention of colorectal cancer by attaching special importance to feasibility. The subjects were patients with multiple colorectal tumors. Two regimens were formulated for prevention of colorectal cancer. One was dietary guidance alone (Regimen I), and the other was dietary guidance plus eating wheat bran biscuits (Regimen II). The main end points of the trial were examinations for recurrence of colorectal tumors after 2 and 4 years. The target number of patients was 200 in total, i.e. 100 for each group. During the 18 months from the beginning of recruiting of subjects (up to November 1994), 28 (97%) of the 29 patients recruited for Regimen I and 32 (97%) of the 33 patients recruited for Regimen II agreed to participate in the trial. The trial progressing well.