New opportunities for screening and early detection of bladder cancer

Abstract

In the United States, over 51,000 new cases of urinary bladder tumors are diagnosed annually. Approximately 75-85% of all newly diagnosed cases are superficial transitional cell carcinomas (TCCs). Incidence is highest (80% of the cases) in the 50-79 year age group. Recent studies have reported that 21-25% of risk for bladder cancer among United States white males is due to occupational exposure. The DuPont Chambers Works in Deepwater, New Jersey, was a major producer of two chemicals now known to be human bladder carcinogens (beta-naphthylamine and benzidine) as well as two suspected human bladder carcinogens [ortho-toluidine and 4,4'-methylene- bis,2-chloroaniline (MOCA)]. Between 1954 and 1982, DuPont screened 1723 exposed employees annually at the Chambers Works using the Papanicolaou test for urinary cytology and microscopic urinalysis. A review of the prior screening program found that employees who developed bladder cancer during this time period were approximately twice as likely to have had hematuria than those comparably exposed who did not develop bladder cancer. Building on this finding, a three-year screening study evaluated a home self-test for microscopic hematuria to aid early detection of treatable urologic conditions among exposed workers at this chemical plant. Every six months, subjects tested their urine at home for 14 consecutive days, for the presence of blood. A high degree of adherence to our protocol (over 92% completed and returned the self-testing record) as well as high compliance with repeat screening (85% returned for screening in subsequent quarters) demonstrated good acceptance and performance of the recommended schedule of self-testing. Through the first 7 periods of screening, two new cases and one recurrence of TCC of the bladder were detected.