STUDIES ON EXPERIMENTAL OVARIAN TUMORS

OVARIAN TUMORS DEVELOPED IN RATS RECEIVING CHEMICAL CARCINOGEN 9, 10-DIMETHYL-1, 2-BENZANTHRACENE

Abstract

There are numerous studies that have been published concerning experimental production of ovarian tumors in laboratory animals with the chemical carcinogen 9, 10-dimethyl-1, 2-benzanthracene (DMBA) and close investigations are in progress on the histogenesis and endocrinologic characteristics of the ovarian tumors induced with this compound. In the previously reported studies, the chemical carcinogen had been applied topically or administered by intravenous route and the neoplasms thereby produced were in most instances granulosa cell tumors, whilst it may fairly be said that reports of production of adenocarcinoma which is of profound interest to us clinicians because of its significant incidence in women as yet are essentially nonexistent. The present investigation represents an experimental attempt to study ovarian tumors induced with DMBA applied by the clipping method which had not been tried by any investigator in the past. There was, as a consequence, solid tumor formation in 36 out of 70 animals (51.4%) in 50 weeks of DMBA application and it is suggested from the data obtained that solid tumors are produced in the ovary with an incidence as high as approximately 70 per cent during the period from 41 to 50 weeks of application. This solid tumor incidence is about four to five times as high as the previously observed one with 20-methylcholanthrene. Moreover, it is considered to be of great significance from the viewpoint of experimental oncology that the solid ovarian tumors produced were of adenocarcinoma type in 18 of the 36 cases.