This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Cohen, S. M. Articles by Friedell, G. H. Search for Related Content PubMed PubMed Citation Articles by Cohen, S. M. Articles by Friedell, G. H.

Early Lesions in Experimental Bladder Cancer: Experimental Design and Light Microscopic Findings¹

Department of Pathology, St. Vincent Hospital, and Department of Pathology, University of Massachusetts Medical School, Worcester, Massachusetts 01610

N-[4-(5-Nitro-2-furyl)-2-thiazolyl]formamide (FANFT) fed to male and female Fischer rats at a dose of 0.2% of the diet induces lesions of the urinary bladder which progress from mild hyperplasia at 2 to 4 weeks, to moderate hyperplasia at 6 to 8 weeks, severe nodular and papillary hyperplasia at 10 to 14 weeks, and microinvasive carcinomas by 25 weeks as observed by light microscopy. Male Fischer rats fed FANFT for 2 or 4 weeks and then maintained on control diet show regression of the bladder lesions within 2 weeks to normal-appearing mucosa which persists through 50 weeks. Rats fed FANFT for 6 weeks show regression of the moderately hyperplastic epithelium to normal within 4 weeks after being placed on control diet which persists through 50 weeks. Rats fed FANFT for 8 or 10 weeks show regression of the hyperplastic bladder epithelium within 2 weeks of receiving control diet, but focal areas of mild hyperplasia are detectable through the 20th week of the experiment. By the 50th week the rats fed FANFT for 8 weeks all had moderate to marked hyperplasia, but the rats fed FANFT for 10 weeks had transitional cell tumors, one of which was invasive through the entire thickness of the bladder wall. The lesions present in rats fed FANFT for 12, 14, or 20 weeks continued to progress to invasive tumors (microinvasive or invasion of muscle) after the rats had been maintained on control diet through 50 weeks. Thus, the hyperplastic lesions developing through 6 weeks of FANFT administration appear to be reversible if FANFT is discontinued, but later lesions appear to be irreversible.

¹ Presented at the Conference "Early Lesions and the Development of Epithelial Cancer," October 21 to 23, 1975, Bethesda, Md. This study was supported in part by USPHS Grant CA 15945 from the National Cancer Institute through the National Bladder Cancer Project.

² Presenter.

³ On leave of absence from the Department of Pathology II, University of Göteborg, Göteborg, Sweden.