Symposium on Mammary Neoplasia

Abstract

An international conference on mammary neoplasia sponsored by the Institute for Medical Research and the National Institutes of Health was held in Cherry Hill New Jersey on November 11-13 1971. 2 reports given focused on the genetic aspects of breast cancer. Bulbrook reported on the urinary steroid excretion patterns in women while Brennan and Wolfe studied the usefulness of xeroradiography in detecting ductal hyperplasia. Paymaster reviewed the epidemiology of breast cancer in India while Ozzello suggested that human breast cancer cells may perform a variety of synthetic and secretory activities. Sarkar suggested that there may be a connection between human breast cancer and RNA viruses and Dalton presented the ultrastructural detail of the mouse feline and human RNA virus. Nandi discussed his recent studies which attempt to locate the mammary tumor virus activity in blood. Concerning tissue and organ culture Lasfargues outlined a new method of growing human breast cancer cells in suspension cultures. Concerning immunology and interferon Blair attempted to elucidate the observation that immunodepression depressed MTV-induced mammary tumor development. Studies have shown striking regression of spontaneous breast cancers in animals following the administration of interferon inducers. Although the role of specific RNA viruses in the oncogenesis of many animal tumors is widely accepted the exact genetic mechanisms by which the viral RNA is expressed causes malignant transformation in the intact animals are not clear. The recent discovery of the enzyme reverse transcriptase and the subsequent demonstration that it is an integral part of all RNA tumor virions has opened a new field of investigation. Spiegelman Schlom Gallo and Temin all reported on it. Muhlbock reported on the influence of prolactin and estrogen on breast cancer as did Meites and Pearson. Thus the relation of an oncogenic virus to breast cancer and the role of reverse transcriptase in tumor viruses were thoroughly discussed at the conference.