Modern molecular and cellular biology have provided powerful new approaches to study
cancer in the research laboratory, but these techniques have not been used extensively in field studies or in screening of high-risk occupational cohorts. The primary objective of this study was to demonstrate the use of cellular and molecular methods in combination with medical and epidemiologic methods to identify
cancer cases, risk factors, and markers in a previously identified and defined cohort of Chinese workers exposed to
benzidine. The screening of exposed workers included occupational, medical, and smoking histories to identify exogenous risk factors, a limited physical examination, Papanicolaou (PAP) urinary cytology, measurement of urine pH, quantitative fluorescence image analysis (QFIA) cytology to detect
DNA hyperploidy, and quantitative fluorescence to detect expression of a low-grade
bladder tumor-associated antigen (p300) by exfoliated urothelial cells and elevated expression of the neu
oncogene product (p185). Detailed analysis of the accuracy of epidemiologic data and the adequacy of samples and accuracy of molecular techniques was carried out. Three groups were included in this study: group 1 included 23
bladder cancer cases who had previously been exposed to
benzidine and served as two surrogates for late-emerging disease; group 2 consisted of 20 subjects with previous exposure history but not previously diagnosed with
bladder cancer; and group 0 was the nonexposure and nonbladder
cancer controls. The results showed that accurate questionnaire data and urine samples can be obtained at remote sites. Among the 20 group 2 subjects, two displayed abnormal findings by both QFIA cytology and p300 expression and were later confirmed to have
bladder cancer.(ABSTRACT TRUNCATED AT 250 WORDS)