No abstract

1,2-Dimethylhydrazine(DMH) was administered s.c. to a group of 20 inbred BD-IX rats at the dose of 15 mg/kg body weight, weekly for 7 months. Intestinal adenocarcinoma have been found in all of the treated animals, often associated with hyperplastic or dysplastic lesions. The intestinal cancers gave metastases in 14 animals. The low incidence of extra-intestinal malignancies, the relatively short induction time, the similarity to human colorectal adenocarcinoma, make the DMH-induced intestinal cancer a highly effective experimental model.

No abstract

The indirect fluorescence method has been used to detect and localize carcinoembryonic antigen (CEA) in specimens of colonic carcinoma, other malignant or benign tumours, and non-cancerous tissues. The antigen was found in 39 specimens of colonic or rectal adenocarcinomas with a characteristic location at the apical pole of the cancerous cells. On the other hand, CEA was not detectable in two samples of anaplastic colonic carcinomas. Furthermore, CEA was occasionally found in some other digestive or non-digestive carcinomas. It was also present in 19 benign colo-rectal polyps examined and in the majority of 85 morphologically non-malignant colonic glands obtained from specimens excised for cancerous or non-cancerous diseases.

There have been several reports on the possible value of measurements of circulating immune complexes for the diagnosis of human breast cancer. To begin to evaluate this possibility and the comparability of results among laboratories, a cooperative study was organized under the auspices of the International Agency for Research on Cancer and the National Cancer Institute (NCI) of the United States. Investigators from four laboratories performing assays for immune complexes were sent coded aliquots of serum specimens from the NCI-Mayo Clinic Serum Bank. The serum panel consisted of specimens from 30 patients with breast cancer (including 20 from untreated patients with resectable tumors), 30 preoperative patients with benign breast disease, and 30 normal women. Although some significant differences in levels of immune complexes between cancer patients and controls were seen, none of the assays had sufficient discriminatory capacity to support optimism about the diagnostic value of this approach. To relate the results with immune complexes to those with a widely used cancer marker, the same sera were also tested for levels of carcinoembryonic antigen (CEA). The CEA assay provided significant discrimination between cancer patients and normal donors but did not significantly discriminate between malignant and benign breast diseases.