Neoplastic Diseases — Multistep Maladies

Abstract

The environment affects living organisms during their whole life time. But endogenous facts provide long term influences on the organisms also. The single steps of such influences may be harmless (and in general they are), but the continued stimulus can harm the tissue cells to the point of transformation and, finally, neoplastic disease. The time frame, depending on tissues and stimuli, can be as short as a few months or extend to last for decades. Dormant tumor cells are a special case. In 1942, I. Berenblum introduced the concept of two-stage carcinogenesis, separating the initiator and the promoter during carcinogenesis. But it sees the problem only from the point of view of the full active carcinogen and the promoting compounds. However, if we regard neoplastic growth not only as tumor production, but also include such topics as host tumor interaction, metabolic interaction, immunology factors, ectopic hormones, and the development of metastasis, then the neoplastic development becomes a chain event.