As noted above we are just completing a molecular epidemiologic case-control study of bladder cancer among Los Angeles County residents, which involved 1514 incident cases and an equal number of age-, sex-, race and neighborhood-matched population controls. In addition to confirming the previously studied quantitative effects of cigarette smoking on bladder cancer risk, we have shown that use of filtered versus non-filtered cigarettes, low-tar versus high-tar cigarettes, and patterns of inhalation had no effect on the overall smoking-bladder cancer association.

We had hypothesized that regular use of analgesics might be a risk factor for bladder cancer, given the established causal relationship between phenacetin and cancer of the renal pelvis which is derived from the same embryological structure and share the same transitional type of epithelium as the bladder. Our data did not support sustained use of analgesics as a risk factor for bladder cancer. But more importantly, we provided the first set of epidemiological data in support of non-steroidal anti-inflammatory drugs (NSAIDs) as chemopreventive agents against bladder cancer, an hypothesis with substantial experimental support.

Although the possible association between hair dye use and bladder cancer risk has been much studied, previous investigations never examined exposure by types of chemicals used. Our study was the first to demonstrate a statistically significant, and dose-dependent relationship between personal use of permanent hair dyes and risk; there was a 3-fold increased risk in women who dyed their hair at least monthly for 15 or more years.