title: Risk of bladder tumors among benzidine workers and their serum properdin levels.
abstract: Serum properdin levels were determined for 21 benzidine operators at 6-month intervals for 2 years after termination of exposure to this carcinogen. Of this group, 7 developed bladder cancers within a 4-month period prior to the initial assay, and all 7 showed properdin levels below the median for the group as a whole. Two of the 3 workers who had had a brief exposure previously to beta-naphthylamine developed benign bladder tumors but had no malignant neoplasms up to 13 years later. The properdin assays of these 3 men remained consistently at or above the median values. No man developed a bladder tumor who was exposed less than 6 years to benzidine, even though 2 of these men showed low properdin levels. Of the 4 whose properdin levels were initially above the median but dropped below in subsequent assays, 3 developed bladder cancers 0.5, 4, and 9 years later. Only 1 man whose properdin level remained high in 1958-59 developed a bladder cancer 7 years later, and his immunologic picture may have been complicated by recovery from a larynx tumor in 1954. Recurrence of bladder tumors among the original 9 cases has occurred only among the 5 whose properdin levels remained below the median. The 1 whose ranking fell most dramatically (from 13 to 19) has had 13 recurrences in 13 years.
mesh_terms: D015081:2-Naphthylamine / Q000506:poisoning; D000328:Adult; D001560:Benzidines / Q000506:poisoning*; D002617:Chemical Industry; D004781:Environmental Exposure; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000097:blood / Q000139:chemically induced*; D011414:Properdin / Q000032:analysis*; D012306:Risk; D013997:Time Factors; D001749:Urinary Bladder Neoplasms / Q000097:blood / Q000139:chemically induced*
chemical_list: D001560:Benzidines; D011414:Properdin; D015081:2-Naphthylamine