Bladder cancer: from pathogenesis to prevention.

Abstract

Bladder cancer continues to be a worldwide problem. However, it is not only its annual incidence of around 357 000 or its annual mortality of around 145 000 (ranking it ninth and 13th as incident cause of cancer and cancer death, respectively) that make it a cause for concern. Rather, it is the growing prevalence and consequent increasing financial cost associated with its assessment, surveillance and treatments, the emotional and physical burdens experienced by so many women and men who encounter the morbidities and mortalities that accompany the various forms of the disease and their specific treatments, and the budgetary considerations that bladder cancer imposes on the individual, society and healthcare systems around the world that are becoming increasingly problematic. Bladder cancer is a disease of the environment and of age. That populations are both increasing in number and growing older compounds the issues that bladder cancer presents. Since more people are living longer more are at potential risk. Furthermore, the changing environments in both developed and developing nations are generating more and higher concentrations of carcinogens that may be associated with the genesis of bladder cancer. The strong associations between cigarette smoking and bladder cancer, similarly strong associations between certain occupations, carcinogen exposure and bladder cancer, and an increasing number of pollutant carcinogens introduced into the environment by growing industrialization are contributing substantively to this prevalent health problem. Unfortunately, public awareness of these circumstances is seriously deficient. As a consequence, cigarette smoking continues to create serious health issues in the genesis of bladder cancer and other health problems, while initiatives to control industrial and occupational exposures to carcinogens have often not kept pace with the increasing production of and associated exposure to carcinogens and the implications of this to populations who become or remain increasingly at risk. The morbidities generated by the growing prevalence of bladder cancer are producing costs that individuals and local economies are ill-equipped to afford. Moreover, little if any progress has been made in affecting the mortalities that result from various forms of bladder cancer despite aggressive and highly complex therapies. Still, recent years have witnessed progress in several areas that are of primary importance in our understanding of bladder cancer. This has allowed a sense of optimism to remain, notwithstanding the societal issues that persist. First, our knowledge of the fundamental genetic changes and biological processes that underlie neoplastic transformation and the genesis of various forms of bladder cancer has grown considerably. Equally important has been the realization that different forms of bladder cancer are likely to be indicative of the existence of different tumour diatheses with distinct intrinsic biological potentials. The correlation of this concept, based on various clinical observations, with that of distinct chromosomal abnormalities seen in particular forms of bladder cancer has offered a basis upon which new insights into the genesis and the design of potential treatments for the different forms of bladder cancer might conceivably be built. Secondly, our appreciation of environmental and host factors that predispose individuals and populations to the development of various forms of bladder cancer has in many instances been confirmed. Thirdly, new understanding of various aspects of the biology of different forms of bladder cancer has offered opportunities to introduce new medical or complementary nutritional treatments that may eradicate, suppress