Effect of colostomy on experimentally produced neoplasms of the colon of the rat

Abstract

As a means of determining the effect of the fecal stream in the pathogenesis of experimentally produced colonic tumors in Wistar strain rats, simple colostomies were performed in the left colon of 57 female rats at approximately 4 cm above the anus. Fifty‐four rats received daily subcutaneous injections, 5 days per week, of the carcinogen 3:2'dimethyl‐4‐aminodiphenyl at a dosage of 2 mg/day/100 Gm body weight. Of the 54 rats, 17 (31.4%) developed either hyperplasia, adenomatous polyps or carcinoma of the large bowel proximal to the colostomy site. None of the 54 rats developed any lesion distal to the colostomy. None of the three control rats with colostomies developed any kind of tumor. Of the colonic lesions that developed, 12 were hyperplasias, 12 were adenomatous polyps and four were carcinomas. All hyperplasia developed at colostomy edge. Diversion of the fecal stream prevents development of colonic neoplasms in Wistar rats in this experimental situation.

The distribution of cancer within the large bowel

“…In the experimental animal, bacteria and faeces have been shown to be necessary in the induction of large-bowel tumours by cycasin (Navarrette and Spjut, 1967;Lacquer, 1964). For some carcinogens, it is known that the precursors are metabolized in the liver, excreted via the bile duct into the gut (caecum), where finally bacteria split off the active agent which presumably is transported via the faeces (Weisburger, 1971).…”

Mouse colostomy model for studies on large bowel cancer

“…Dietary factors such as fiber content implicated in the etiology of colorectal cancer [2] are controlled. Diversion of the fecal stream has previously been shown to alter the induction of colonic neoplasms by carcinogens [6],…”

Das Carcinom am Anus Praeter

“…Die bevorzugte Lokalisation systemisch induzierter Coloncarcinome an der Colostomie war schon anderen Untersuchern aufgefaUen [9,11,16,18,19]. Im Unterschied zu den eigenen Befunden war hier jedoch eine Exposition des Kunstafters gegen ausschliel31ich oder fiberwiegend intralumin~ir transportierte Carcinogene effolgt.…”