Bladder Cancers. Their Process of Development and Its Modification

Much information on the development of bladder cancers and its modification has accumulated. It is generally considered that the presence of chemicals in the environment including carcinogens and modifiers (promoters, inhibitors, anti-promoters, etc.) is responsible for the geographical variation in human neoplasia including urinary bladder cancer development. A diagrammatic representation of the possible interactions between environmental factors and tumor development in man is shown in Fig. 6. Thus if potent carcinogens or promoters are present, neoplasia results, with tumor death occurring within an individual's normal lifetime. However, lack of such substances or the existence of powerful inhibitory factors is presumed to slow down the process, so that the normal life-span is not affected. It is therefore of prime importance for thorough awareness of the factors involved to be generated.