Almost all bladder malignancies originate on the uroepithelial surface. The majority of patients who die from bladder cancer do so from metastatic disease; treatment for metastatic bladder cancer is rarely, if ever, curative.[1] The overwhelming majority of patients with metastases have concomitant or prior muscularis propria (stage T2+) invading lesions.[2] Approximately 90% of patients with muscularis propria invading bladder cancer present with this diagnosis, however,[3,4] and do not come from the much larger pool of patients with recurring superficial transitional cell carcinomas (TCCs). The goal of screening is the early detection of bladder cancer that is destined to become muscle invading. Although one study reports that approximately 30% of patients with superficial TCC followed for 20 years will eventually die from this disease,[5] these data remain unconfirmed, are at odds with other reports,[6] and may reflect outmoded patterns of diagnosis, classification, and management.

Because bladder cancer is almost never incidentally found at autopsy, the preclinical duration in which it has not yet caused symptoms, but in which it can be detected by cystoscopy, is probably brief. This rapid growth rate is supported by clinical experience [7] and implies that screening would have to be performed at frequent intervals.

Screening Methods

Cystoscopy and cytology

The use of cystoscopies and bladder wash/urinary cytologic examinations has proven quite successful in the surveillance and management of patients with previously treated bladder cancers.[8] These means are not practical in individuals without a history of bladder cancer, however, because of expense and morbidity.

Hematuria

Although hematuria is the most common presenting sign of bladder cancer, most individuals with hematuria do not have bladder cancer. In the general population, the prevalence of asymptomatic gross hematuria is about 2.5% while the prevalence of asymptomatic microhematuria is about 13%.[9] In a recent prospective analysis of patients attending a hematuria clinic in the United Kingdom, 183 (19.2%) of the 948 patients with gross hematuria were found to have bladder cancer on cystoscopy.[10] In contrast, only 47 (4.8%) of the 982 patients with microhematuria were found to have bladder cancer.

One-time hematuria testing

Two groups have reported on the use of testing a single urine specimen for blood to detect urologic malignancies, serious urinary tract diseases, and bladder cancers. Both studies were performed retrospectively to ascertain information from patients who were seen at a large multispecialty clinic [9] or who subscribed to a large health maintenance organization (HMO) and were tested in a "multiphasic screening."[11] Because of the retrospective nature of each study, neither was designed to specifically look for bladder cancer detection or to focus on the population at highest risk (men aged 50 years and older). Both studies concluded that single hematuria testing was not effective in diagnosing bladder cancer. A longer follow-up of the HMO study indicated that individuals with microhematuria were at a higher risk for subsequent development of muscle-invading bladder cancer, with a latency of 3.5 to 14.5 years.[12] There is insufficient evidence to indicate that single hematuria testing is effective in screening for bladder cancer, and there is no evidence that single hematuria testing results in reduced mortality from the disease.