The global burden of urinary bladder cancer

Statistics on the incidence of bladder cancer are particularly hard to interpret, because of changing classification, variations in counting of multiple cancers in the same individual and, most importantly, the variable inclusion of non-invasive cancers in different data sets. Mortality statistics are almost certainly more comparable, but as indirect estimators of disease risk, require some cautious interpretation, because of differing survival between populations, and over time. Cancer of the bladder is estimated to be the ninth most common cause of cancer worldwide (357 000 cases in 2002) and the 13th most numerous cause of death from cancer (145 000 deaths). Rates in males are three to four times those in females. Incidence rates are high in many southern and eastern European countries, in parts of Africa and the Middle East, and in North America. The highest estimated mortality is in Egypt, where rates are more than three times greater than the highest rates in Europe and eight times those in the USA. In the USA, the incidence in whites is higher than in blacks. In general, in Western countries, incidence rates have been rising, but the increase has slowed or stopped in many. Mortality rates are, for the most part, decreasing. Trends are more variable in developing countries. To some extent, the geography and time trends are related to prevalence of known risk factors, especially exposure to tobacco (responsible for almost one-third of bladder cancer deaths) and, in some specific areas, schistosomiasis.