Precipitating factors causing hyperbilirubinemia during chronic hepatitis C treatment with paritaprevir/ritonavir/ombitasvir and dasabuvir

BACKGROUND

Hepatic decompensation is a fatal on-treatment side effect during chronic hepatitis C treatment with paritaprevir/ritonavir/ombitasvir and dasabuvir (PrOD). Prompt bilirubin testing can reveal hepatic failure in susceptible patients, and clinical parameters precipitating early elevation of bilirubin can warn clinicians to avoid PrOD prescription.

METHODS

This retrospective study included 169 Hepatitis C virus (HCV)-genotype 1b patients who underwent a 12-week course of PrOD with or without ribavirin. Laboratory data underwent χ analysis with Fisher's exact test to determine the precipitating factors causing hyperbilirubinemia in patients who had received 1 week of treatment.

RESULTS

Sustained viral response was achieved in 164 patients (97.0%). Total bilirubin was ≥2 mg/dL (21.3%) in 36 patients after 1 week of treatment. Pretreatment white blood cell (WBC) <4500/µL and platelet <100,000/µL correlated with total bilirubin ≥2 mg/dL (relative risk [RR]: 21.64, 95% CI: 5.23-89.64, p < 0.001) after 1 week of treatment. Pretreatment platelet ≥100 000/µL and WBC <4500/µL correlated with direct bilirubin ≥0.45 mg/dL (RR: 6.56, 95% CI: 1.42-30.38, p = 0.016) and indirect bilirubin ≥0.6 mg/dL (RR: 4.77, 95% CI: 1.03-22.15, p = 0.046). Pretreatment platelet <100,000/µL with F3/F4 fibrosis correlated with first week total bilirubin ≥2 mg/dL (RR: 3.57, 95% CI: 1.35-9.09, p = 0.010).

CONCLUSION

PrOD is an effective antiviral regimen for HCV genotype 1b patients. Total bilirubin ≥2 mg/dL after 1 week of treatment serves as an early warning of irreversible progression toward hepatic decompensation, and the current study provides a guide by which to monitor chronic hepatitis C patients undergoing PrOD treatment.

Patch testing in Lao medical students

Background

Dermatological services in Laos, South East Asia are limited to the capital and patch testing is currently not available, so no data exists regarding the common cutaneous allergens in this population.

Objectives

The aim of this study was to document positive patch tests in medical students without evidence of contact dermatitis in Laos.

Patients/Materials/Methods

One hundred and fifty medical students were patch tested using TRUE Test^® panels 1 to 3 (35 allergens). Readings were taken at Days 2 and 4.

Results

Thirty-eight students (25.3%) had a positive reaction to at least one allergen, accounting for 52 reactions in total. The proportion of the students with positive patch test reading was significantly higher in the female [33/96 (34%)] than in the male [5/54 (9%)], p<0.001. The most common allergens were: nickel (10%), gold (6.6%), thiomersal (6.6%), cobalt dichloride (2%) and p-tert-Butylphenol formaldehyde resin (2%). Balsam of Peru (0.66%), black rubber mix (0.66%), Cl+Me-Isothiazolinone (0.66%), fragrance mix 1 (0.66%), quinolone mix (0.66%), methyldibromo glutaronitrile (0.66%), mercapto mix (0.66%), epoxy resin (0.66%), paraben mix (0.66%), thiuram (0.66%) and wool alcohols (0.66%) accounted for all of the other positive reactions.

Conclusion

This study represents the first documented patch test results in Lao medical students and in the adult Lao population. The results of this study will inform any future research into contact allergy in Laos and give an insight into the background level of contact sensitivity in this population.

Black rubber sensitization by bicycle handgrips in a child with palmar hyperhidrosis

Black rubber is mainly an occupational source of contact sensitization; however, several unusual causes of non-occupational black rubber allergy are reported in the literature. A 10-year-old nonatopic Turkish boy with palmar hyperhidrosis developed acute vesicular bilateral palmar dermatitis following 2 to 3 weeks of intensive use of a new bicycle. The handgrips of the bicycle were made of black rubber. Patch testing showed a strong positive reaction to N-isopropyl-N-phenyl-4-phenylenediamine (the main sensitizer in black rubber) and questionable papular reactions to pieces of the black rubber handgrip. Additional cross-sensitization was found to p-phenylenediamine. There was no previous contact with black rubber or with any material that would contain p-phenylenediamine (eg, black henna dye). In conclusion, this was an unusual pediatric case of non-occupational allergic contact dermatitis from N-isopropyl-N-phenyl-4-phenylenediamine in black rubber bicycle handgrips. The young age of the patient and the development of contact sensitization within a relatively short period were striking. The release of the sensitizer from black rubber and the skin penetration were possibly enhanced by continuous friction and the accompanying hyperhidrosis, suggesting that the black rubber bicycle handgrip was the primary source of sensitization.

Soccer shin guard reactions: allergic and irritant reactions

In spite of the worldwide popularity of soccer among youth and the common requirement of the use of protective shin guards, reports of allergy to shin guards is sparse. This is surprising in light of the fact that this equipment is often made of materials that are reported to cause allergies, and that friction and moisture from the use of these shin guards during the sport would seem to predispose soccer players to the development of an allergic response. We present eight patients that presented for evaluation of dermatitis under their shin guards--some of which had allergy to their shin guards and some of which were diagnosed as having an irritant reaction.

Biological activity resulting from exposure to aquatic environmental genotoxic pollutants in northern Egypt

We estimated pollution in Lake Edku and the Mediterranean Sea, El-Maadiya Region, with 3 aromatic amines (1-naphthylamine, 2-naphthylamine and benzidine) in the muscle tissue of fish. There were marked seasonal variations in the aromatic amine levels. We also determined oxidative stress (blood glutathione, and catalase activity) and genotoxic effects (chromosomal aberrations and urinary metabolites) in fishermen from each area. The fishermen suffered from oxidative stress and had high levels of the urinary metabolite sulfanilamide [mean (microg/mg creatinine): Lake Edku 20.7, Mediterranean 14.5, controls 5.3]. Frequencies for total chromosomal aberrations were significantly raised in the peripheral blood lymphocytes of fishermen in both areas [frequency (per 100 metaphases): Mediterranean 67, Lake Edku 45, controls 14].

Occupational allergic contact dermatitis from antioxidant amines in a dental technician

We describe an 18-year-old dental technician who presented with dry hyperkeratotic lesions on his left palm that were limited to an area that was in contact with a container in which he had prepared the molds for a dental prosthesis. On patch testing, he had a positive reaction to black rubber mix and its components N-cyclohexyl-N'-phenyl-4-phenylenediamine, N,N'-diphenyl-4-phenylenediamine, and N-isopropyl-N'-phenyl-4-phenylenediamine, as well as to a piece of the rubber container. Thin-layer chromatography (TLC) of a piece of the rubber container confirmed the presence of the para-phenylenediamine mix. Results of patch-testing with TLC were positive after 48 and 96 hours. The lesions resolved when the patient stopped using the container. The patient was diagnosed with occupational allergic contact dermatitis. We also review the dermatoses caused by antioxidant amines.

Bladder tumours in rubber workers: a factory study 1946-1995

BACKGROUND

Prior to December 1949, some British rubber industry workers were inadvertently exposed to the human bladder carcinogen beta-naphthylamine, which was present as a contaminant (at 0.25%) in antioxidants used in manufacturing. This study follows a composite cohort of 6450 men employed at a large tyre factory either during the 'at-risk' period or just after it.

METHODS

A group of 2090 at-risk men (employed 1945-1949) and 3038 men, first employed only after January 1950, when the carcinogen had been removed, were followed for their bladder cancer morbidity and mortality experiences.

RESULTS

Fifty-eight tumours were registered for those at risk, whereas only 33.9 were expected at national standardized registration rates [SRRN = 171 and 95% confidence interval (CI) = 130-221]. Thirty-nine bladder tumours were reported for the post-1950 intake, whereas 38.3 were expected (SRRN = 102 and 95% CI = 72-139). The use of mortality data did not reveal any underlying hazard because 12 of the 58 at-risk workers with tumours were still alive at the study end date. In only 16 instances was bladder cancer actually certified as the underlying cause of death. Plotting cases by their location of work on a factory plan assisted the interpretation.

CONCLUSIONS

A statistically significant elevated risk of bladder cancer for the exposed workforce was evident, but this reversed when the carcinogen was removed from processing in October 1949. The use of morbidity (incidence) data in long-term studies of occupational bladder cancer should be the required methodology if the hazard and risk are not to be underestimated.

The Drake Health Registry Study: findings from fifteen years of continuous bladder cancer screening

BACKGROUND

The Drake Health Registry Study (DHRS) is an ongoing bladder cancer screening program initiated in 1986 due to workers' probable past exposure to the bladder carcinogen, beta-naphthylamine (BNA).

METHODS

At periodic screening visits, a health survey is administered and three screening tests are applied to a urine sample, urinalysis (UA), papanicolaou (PAP), and quantitative fluorescence image analysis (QFIA). Positive screens are eligible for a free bladder cystoscopy with random biopsies.

RESULTS

Forty of 51 persons eligible for diagnostic evaluation underwent cystoscopy. One person was diagnosed with carcinoma in situ, two with transitional cell papilloma, 14 with dysplasia, two of which developed transitional cell carcinoma; 26 had bladder abnormalities such as chronic inflammation, chronic cystitis, atypical changes, atypia, hyperplasia, or papillary clusters.

CONCLUSIONS

The DHRS continues to identify early stage bladder cancer and other abnormalities among workers exposed to BNA before 1981 and generates useful clinical, psycho-social, and epidemiologic data.

Re-evaluation of the latent period of bladder cancer in dyestuff-plant workers in Japan

BACKGROUND

The carcinogenesis of benzidine (BZ) and beta-naphthylamine (BNA) for bladder is well known. Although it was thought to be rare to develop occupational bladder cancer more than 20 years after the exposure to these chemicals, there are still new clinical cases even 30 years after exposure. The purpose of this study was to re-evaluate the latent carcinogenic period of BZ and BNA, in order to set the safety period after exposure for the health surveillance system.

METHODS

The subjects were 236 dyestuff-plant workers in Tokyo, who had been exposed to these dyestuffs. The incidence of bladder cancer and its histopathology in this group was surveyed in the period from 1962 to 1996.

RESULTS

Nineteen workers (8.1%) were found to have bladder cancers. The exposure period for these 19 patients was 82.0 +/- 50.2 months. The mean +/- SD latent period from the subjects' initial and final exposure until tumor development was 29.5 +/- 8.2 years and 20.1 +/- 10.6 years, respectively. Significantly, a negative correlation (Pearson) was observed between the exposure period and the latent period from the end of exposure to cancer onset (R = -0.544, P < 0.05). All tumors except one were transitional cell carcinoma. Flow cytometric analysis was performed in 11 patients and all of these patients had DNA aneuploidy.

CONCLUSIONS

The latent periods of bladder cancer caused by BZ and BNA were longer than previously expected. It is necessary to survey the onset of bladder cancer in exposed workers more than 30 years after the initial exposure.

Detection of carcinogenic aromatic amines in the urine of non-smokers

Smoking is thought to be one of the most important anthropogenic risk factors involved in the development of urinary bladder cancer in humans. Tobacco smoke contains a complex mixture of chemicals including potent carcinogens such as aromatic amines. In the present study the amounts of several freebase aromatic amines including the potent carcinogens 2-aminonaphthalene and 4-aminobiphenyl have been analyzed in the urine of 48 German urban living smokers and non-smokers. The results indicate that (i) both groups excrete the identical set of four aromatic amines; (ii) smokers excrete approximately twice the total amount of these amines, but similar amounts of 2-aminonaphthalene and 4-aminobiphenyl are found in non-smokers; and (iii) the excreted aromatic amines are decomposed in the urine within a few hours thus, explaining why aromatic amines are difficult to detect in this matrix. Their decomposition could be prevented by adding small amounts of p-toluidine to the freshly collected urine. Unlike smokers the origin of aromatic amines detected in the urine of non-smokers is at present unknown. Based on the cotinine levels found in the urine of non-smokers environmental tobacco smoke can be excluded as a major source of aromatic amines. In addition, neither diesel exhaust-related nitroarenes nor the corresponding amino-derivatives, to which they may be metabolically converted, were found. The detected urinary levels of aromatic amines arising from sources other than tobacco smoke or diesel exhaust may play a role in the bladder cancer etiology of non-smokers.

A further cohort study of workers employed at a factory manufacturing chemicals for the rubber industry, with special reference to the chemicals 2-mercaptobenzothiazole (MBT), aniline, phenyl-beta-naphthylamine and o-toluidine

OBJECTIVES

To investigate mortality and cancer morbidity in workers from a factory manufacturing chemicals for the rubber industry.

METHODS

The mortality (1955-96) and cancer morbidity experience (1971-92) of a cohort of 2160 male production workers from a chemical factory in north Wales were investigated. All subjects had at least 6 months employment at the factory and some employment in the period 1955-84. Detailed job histories were abstracted from company computerised records and estimates of individual cumulative exposure to 2-mercaptobenzothiazole (MBT) and its derivatives were obtained, with a job exposure matrix derived by a former factory hygienist. Durations of employment in the aniline, phenyl-beta-naphthylamine (PBN) and o-toluidine departments were also calculated. Two analytical approaches were used, indirect standardisation and Poisson regression.

RESULTS

Based on serial rates for the general population of England and Wales, observed mortality for the total cohort was close to expectation for all causes (observed (obs) deaths 1131, expected (exp) deaths 1114.5, standardised mortality ratio (SMR) 101), and for all cancers (obs 305, exp 300.2, SMR 102). There was a significant (p < 0.05) excess mortality from cancer of the bladder in the 605 study subjects potentially exposed to one or more of the four chemicals being investigated (obs 9, exp 3.25, SMR 277, 95% confidence interval (95% CI) 127 to 526). This excess was dependent primarily on deaths occurring > 20 years after first exposure in those who started employment before 1955 (obs 7, exp 1.25, SMR 560, 95% CI 225 to 1154, p < 0.001). There were 30 subjects in the total study cohort who, on the basis of death certificates or cancer registration particulars, had had malignant bladder cancer. In separate analyses of the four exposure history variables (after adjustment for age), Poisson regression showed significant positive trends for risk of notification of bladder cancer increasing with cumulative duration of employment in the PBN (p < 0.001) and o-toluidine departments (p < 0.01); similar findings were not obtained for cumulative exposure to MBT or for duration of employment in the aniline department. In a simultaneous analysis of all four chemical exposure variables, a significant positive trend remained for duration of employment with exposure to PBN (p < 0.05). Further analyses of all cases of bladder cancer (malignant and benign diagnoses) used employment histories lagged by 15 years; similar findings were obtained.

CONCLUSIONS

It seems likely that some members of this cohort have had occupational bladder cancer. Confident interpretation is difficult because of small numbers in the exposed subcohorts, relatively crude measures of exposure assessment for the four chemicals under study, and presence of unconsidered potential chemical confounders. The simplest interpretation of the findings about bladder cancer may be that PBN (or a chemical reagent or chemical intermediate associated with its production at this factory in the 1930s and 1940s) is a bladder carcinogen. Priority should be given, however, to obtaining information on the cancer experience of other working populations exposed to PBN or to o-toluidine.

[Occupational experience, epidemiologic observations, and scientific evidence in an illustrative case: adverse effects of the production and use of aromatic amines in Italy]

Economical, social and technical interrelations between synthetic dyes' production and bladder cancer in workmen engaged in the manufacture are reviewed. International situation is the background of Italian situation, mainly of the Lombardy region and Turin area. For decades social actors, individuals and institutions, acted as separate bodies, contributed to delay and omit the protection of workers' health. The situation changed when scientific knowledge, technical developments and workers' commitment prioritized workers' health as a main goal. The epidemic of bladder cancers among dyestuff workers was a cornerstone in the development of a different scenario in the production responsibility, workers' participation and eventually scientific community. The authors hypothesise that in our country these events stimulated the growth of epidemiology and epidemiologists; furthermore since then institutions promulgated a new and up-to-date wave of protective legislation in the workers' H&S field.

Relationship between glutathione S-transferase M1 deficiency and urothelial cancer in dye workers exposed to aromatic amines

PURPOSE

It is speculated that the susceptibility to urothelial cancer in dye workers who are exposed to aromatic amines is affected not only by occupational environmental factors but by host specific factors. We evaluated the interaction between glutathione S-transferase M1 gene deficiency and the occupational environmental factors associated with urothelial cancer.

MATERIALS AND METHODS

The study included 137 workers who had prior exposure to dyestuff intermediates, of whom 36 had urothelial cancer. The prevalence of a glutathione S-transferase M1 gene polymorphism was investigated using polymerase chain reaction. The relationship between the glutathione S-transferase M1 0/0 gene and occupational environmental factors in the onset of urothelial cancer was examined by multivariate analysis.

RESULTS

The prevalence of glutathione S-transferase M1 gene deficiency did not differ significantly between the urothelial cancer (21 cases, 58.3%) group and the cancer-free (47, 46.3%) group. It was estimated that 29.6% of the urothelial cancers in these dye workers was attributable to the glutathione S-transferase M1 0/0 gene. Analysis using multiple logistic models showed low predictive ability for urothelial cancer due to glutathione S-transferase M1 gene deficiency (p = 0.084, odds ratio 2.260, 95% confidence interval [CI] 0.904 to 5.652). A history of working in small factories (p = 0.000, odds ratio 7.404, 95% CI 2.854 to 19.206) and a long period of exposure (p = 0.016, odds ratio 5.051, 95% CI 1.371 to 18.612) significantly predicted cancer.

CONCLUSIONS

We demonstrated a strong trend using the multiple logistic analysis of the contribution of glutathione S-transferase M1 gene polymorphism and occupational environmental factors. Therefore, the glutathione S-transferase M1 enzyme might have an important role in the detoxification of aromatic amine derived carcinogens. Occupational environmental factors, however, might contribute more than a glutathione S-transferase M1 gene deficiency to the occurrence of urothelial cancer among individuals exposed to aromatic amines, because of the extremely potent carcinogenicity of some occupational environmental factors.

Aromatic amines and cancer

Epidemiological evidence on the relation between aromatic amines and cancer risk is reviewed. In particular, cancer risk in humans resulting from exposure to aromatic amines from occupational sources and tobacco smoking is assessed with reference to ecologic, cohort, and case-control studies. Seven arylamines have been classified by the International Agency for Research on Cancer: benzidine-based dyes and MOCA (4,4'-methylene bis 2-choloroaniline) were considered 'probably' carcinogenic, Group 2A, because of a high level of evidence in experimental animals; two occupational chemicals (2-naphthylamine and benzidine), one drug (Chlornaphazine), and two manufacturing processes (manufacture of auramine and magenta) were included in Group 1 on the basis of 'sufficient' evidence of carcinogenicity in humans. Occupational exposures to aromatic amines explain up to 25 percent of bladder cancers in some areas of Western countries; these estimates might be higher in limited areas of developing countries. Aromatic amines contaminate the ambient air as a component of environmental tobacco smoke. There is increasing evidence that the excess of bladder cancer in smokers is attributable to aromatic amines rather than to other contaminants of tobacco smoke such as polycyclic aromatic hydrocarbons (PAH). A modulating role in the risk of bladder cancer associated with exposure to aromatic amines is played by metabolic polymorphisms, such as the N-acetyltransferase genotype, raising important social and ethical issues. The consistent observation of a difference between men and women in bladder cancer risk, after allowing for known risk factors, suggests consideration of gender-related biological determinants for future investigation.

Oils and cancer

Epidemiologic evidence on the relationship between mineral oil exposure and cancer is reviewed. The review is restricted to occupations involving substantial dermal and inhalational exposure and for which an epidemiologic literature exists: metal machining, print press operating, and cotton and jute spinning. Mineral oils are complex mixtures of aliphatic hydrocarbons, naphthenics, and aromatics, the relative distribution of which depends on the source of the oil and the method of refinement. End-use products contain a variety of additives, and contamination by other agents generally occurs during use. Suspect agents include polycyclic aromatic hydrocarbons (PAH) (particularly benz[a]pyrene), nitrosamines, chlorinated paraffins, long-chain aliphatics, sulfur, N-phenyl-2-naphthylamine, and formaldehyde. The heterogeneity of this exposure makes epidemiologic study difficult and meta-analysis inappropriate. Nonetheless, several associations emerge from the literature with varying degrees of support. There is clear evidence that early formulations of mineral oils used in cotton and jute spinning and in metal machining were carcinogenic to the skin. Associations of mineral oil exposure with laryngeal and rectal cancer have received some support in the literature, particularly with respect to straight oils. Evidence is suggestive that grinding operations (which can entail either mineral oil-based or ethanolamine-based fluids) are associated with excess risk of cancer of the esophagus, stomach, and pancreas. A number of bladder cancer case-control studies have noted an association with work as a machinist. There is limited evidence of an association with cancer of the colon, prostate, and sinonasal region. Several studies of printers have yielded positive findings for lung cancer, whereas studies in metal machinists have been generally negative. The PAH and nitrosamine content of current formulations is lower than in the past and the implications of these changes in composition to the carcinogenicity of the formulations are not yet known.

[Clinical study of occupational uroepithelial cancer]

We studied 438 persons who were engaged in the production and use of aromatic amines (benzidine sulfate, beta-naphthylamine, alpha-naphthylamine and dianisidine). Among these 438 persons, 88 new cases of occupational uroepithelial cancer had occurred from 1949 to 1995. The incident rate of occupational uroepithelial cancer was 20.1%. The average exposure period of these 88 cases to the aromatic amines was 7.40 years (range, 0.75-26.75), and the incidence rate of tumors increased with the length of exposure to aromatic amines. The average latent period was 26.79 years (range, 1.33-48.50), and the average age of first onset was 52.59 (range, 24-79). Recently it has been determined that the longer the latent period, the older the age of first onset. Of these 88 cases, the tumor sites were bladder in 67 cases (76.1%) and upper urinary tract (renal pelvis and/or ureter) in 5 cases (5.7%). The other 16 cases (18.2%) were the bladder and upper urinary tract. The screening examination for chemical workers using urinary cytology was begun in 1962. In our cases, urine cytology was a useful method for diagnosing occupational uroepithelial cancer. As for initial treatment of the 88 cases, transurethral surgery was most frequently performed, that is on 58 cases (65.9%). However, eight cases (9.1%) had to undergo a total nephroureterectomy, and six cases (6.8%) had a total cystectomy. Recurrence was observed in 61 cases (69.3%) out of the 88 patients with an average of 1.81 times. The other organic cancers developed in 39 cases (8.9%) out of 438 workers who were exposed to aromatic amines and in 8 cases out of 88 patients (9.1%). Prognosis of the 88 patients is that, the number of alive and dead is 51 (58.0%) and 37 (42.0%) respectively on December 31, 1995. Twenty-eight patients (31.8%) died of uroepithelial cancer, and five patients (5.7%) died of other organic cancers. The survival rates of 5, 10, 15 and 20 years was 87.9%, 74.0%, 65.9% and 56.3%, respectively. From these results, patients with occupational uroepithelial cancer and workers who are exposed to aromatic amines should undergo long term observation.

Exposure to aromatic amines and ras and c-erbB-2 overexpression in bladder cancer

We have analyzed the bladder biopsies of six bladder cancer patients exposed to high levels of 2-naphthylamine and benzidine, 11 unexposed bladder cancer patients, six subjects with benign conditions of the bladder, and 16 healthy subjects. Immunohistochemical analysis of the p21 and p185 protein products, for overexpression of ras and c-erbB-2 oncogenes, was performed. Overexpression of ras was found in four of six exposed cancer patients, 3 of 11 unexposed cancer patients, zero of six benign disease patients, and zero of 16 healthy subjects. The odds ratio for ras overexpression, comparing exposed with unexposed cases, was 5.3 (90% confidence interval 0.6 to 64). Overexpression of c-erB-2 was apparently not associated with occupational exposure.

Increase in CD57 + CD16-lymphocytes in workers exposed to benzidine and beta-naphthylamine: assessment of natural killer cell subpopulations

Previously, we found a decrease in CD4 + CD45RA + T lymphocytes in workers exposed to the aromatic amines (AAs) [benzidine (BZ) and beta naphthylamine (BNA)]. For further investigation of the effects of AAs on lymphocyte subpopulations, we measured natural killer (NK) cell subpopulations using two-color staining with anti-Leu7 (CD57) and anti-Leu11 (CD16) monoclonal antibodies in peripheral blood in 78 male dyestuff workers. The workers had been exposed to AAs before 1972 at a chemical plant, either in the production of AAs (40 workers, high-exposure group) or in other work that involved handling dyestuffs (38 workers, low-exposure group). The controls were 30 "healthy" male volunteers without a history of occupational exposure to AAs or hazardous chemicals. The number of CD57 + CD16- cells in the high-exposure group was significantly higher than that in the controls (P < 0.01, analysis of covariance with age as a covariate). No significant differences were found in CD57 + CD16-, CD57 + CD16+ and CD57- CD16 + NK cells between the low-exposure group and the controls. It is suggested that a decrease in the number of CD4+ T lymphocytes following exposure to AAs might be compensated by the increase in CD57 + CD16- cells, i.e. circulating peripheral lymphocytes with poor NK cell activity.

Cancer occurrence among dyestuff workers exposed to aromatic amines. A long term follow-up study

BACKGROUND

Although the occupational exposure to some aromatic amines is recognized to cause bladder carcinoma, the long term effect of such exposure on the risk for disease, including other malignant tumors, remains unknown.

METHODS

A total of 442 dyestuff workers exposed to one or more substances including benzidine (BZ), beta-naphthylamine (beta-N), alpha-naphthylamine (alpha-N), and dianisidine were followed completely until December 1992 (average time since first exposure, 39.4 years). Besides the underlying cause of death, the incidence of urothelial carcinoma was determined by periodic urologic screenings.

RESULTS

Analyses of site-specific cancer mortality revealed a remarkable increased risk for bladder carcinoma for those engaged in BZ manufacture (standardized mortality ratio [SMR] = 63.6), BZ use (SMR = 27.0) and beta N manufacture (SMR = 48.4), but not for those who were exposed to alpha-N. The increased risk of cancer mortality for other organs was not significant for any exposure classes. The crude incidence rate per 1000 person-years of bladder carcinoma was estimated to be 8.7 for those engaged in BZ manufacture, 2.9 in BZ use, 7.7 in beta-N manufacture and 1.0 in beta-N use. Regardless of the class or type of exposure, the adjusted incidence rate of urothelial carcinoma increased with the duration of exposure. The adjusted incidence rate for BZ manufacture remained high (3.8-12.8) during the entire observation period, whereas that for BZ use increased from 0.0 to 4.4 as the time since first exposure increased from less than 10 years to 30+ years.

CONCLUSIONS

Occupational exposure to either BZ or beta-N demonstrated an extremely strong and prolonged effect on workers' risk for urothelial carcinoma, particularly for bladder carcinoma, but not for malignant neoplasms of other organs.

Cancer incidence and mortality among beta-naphthylamine and benzidine dye workers in Moscow

BACKGROUND

Cancer incidence and mortality were evaluated among 4581 aniline dye production workers in Moscow.

METHODS

A historical cohort was assembled and followed-up from 1 January 1975 to 31 December 1989. Moscow district oncologic dispensary registries furnished case ascertainment and employer records provided job exposure data. Expected cancers and deaths were calculated based on gender-, age-, and calendar time-specific incidence and mortality rates for the Moscow general population applied to the cohort's person-years of follow-up. Disease-specific standardized mortality and incidence values were derived from ratios of observed to expected cancers.

RESULTS

Men experienced elevated total cancer mortality (standardized mortality ratio [SMR] = 125; 95% CI: 110-142) and urinary bladder cancer mortality (SMR = 279; 95% CI: 192-391), and increased all malignancy (standardized incidence ratio [SIR] = 142; 95% CI: 125-160), oesophageal (SIR = 203; 95% CI: 108-347), respiratory tract (SIR = 154; 95% CI: 120-194) and bladder (SIR = 394; 95% CI: 268-559) cancer incidence. Women had elevated oesophageal (SMR = 313; 95% CI: 124-664) and bladder (SMR = 311; 95% CI: 149-571) cancer mortality and elevated all malignancy (SIR = 124; 95% CI: 106-144), oesophageal (SIR = 348; 95% CI: 140-719), and bladder (SIR = 861; 95% CI: 458-8002) cancer incidence. Bladder cancer rate increased with employment duration and younger age first hired. Rate estimates were highest among beta-naphthylamine exposed workers but was also increased among workers with other chemical exposures. A cancer prevention and control effort that limited benzidine exposure to < or = 3 years was apparently unsuccessful as indicated by a significant excess of bladder cancer (SIR = 1773; 95% CI: 356-5180) among these workers.

CONCLUSION

Relative rates of oesophageal, lung, and stomach cancer were also elevated among all workers, but did not increase with total years worked, age first hired, or year first hired, suggesting a non-occupational aetiology.

Epidemiology of cancer from exposure to arylamines

Occupational exposure to arylamines such as benzidine, 2-naphthylamine, and 4-aminobiphenyl is associated with exceptionally elevated risks of bladder cancer (up to 100-fold or more). In one plant, all 15 workers involved in distilling naphthylamine developed bladder cancer, suggesting that for high levels of exposure to potent carcinogens individual susceptibility is irrelevant. More recently, exposure to other arylamines also has been suggested to increase the risk of bladder cancer in humans. In addition, cohort and case-control studies suggest that several job titles or exposures may involve elevated risks of bladder cancer. Some of these jobs or exposures (such as in the aluminum industry) are associated with exposure to arylamines. Arylamines are found also in tobacco smoke, and different sources of evidence suggest that they can explain the risk of bladder cancer, which has been shown clearly in smokers. Epidemiologic analyses of timing of exposure in workers occupationally exposed to arylamines or in air-cured tobacco smokers suggest that arylamines exert both an early- and a late-stage activity, compatible with a two-mutation theory of bladder carcinogenesis.

Decrease of CD4-positive T lymphocytes in workers exposed to benzidine and beta-naphthylamine

T lymphocyte subpopulations (CD4+, CD8+, and CD3+ cells), Leu 11a-(CD16) positive lymphocytes, and total lymphocytes in peripheral blood in 52 male dyestuff workers were analyzed to determine the effects of benzidine and beta-naphthylamine on the human immune system. The workers had been exposed prior to 1972 to benzidine and beta-naphthylamine (aromatic amines) at a chemical plant. The dyestuff workers included 27 workers who had engaged in production of aromatic amines (i.e., high-exposure group) and 25 workers who had handled dyestuff at their job (low-exposure group). The total and relative numbers of CD4+ and CD3+ T lymphocytes in the high-exposure group were significantly lower than those found in the control (no-exposure) group (p < .01). Relative--but not total--number of CD16+ lymphocytes in the high-exposure group was significantly higher than in the control group (p < .05). However, there were no significant differences between the low-exposure group and control group with respect to all T lymphocyte subpopulations, CD16+, and total lymphocytes. Perhaps the number of circulating CD4+ T lymphocytes decreases in workers exposed to aromatic amines. It is concluded that measurement of CD4+ lymphocytes provides a useful biological marker of past exposure to aromatic amines.

Evaluation issues in the Drake Chemical Workers Notification and Health Registry Study

The Drake Chemical Workers' Health Registry combined notification of workers about bladder cancer risk with access to a free program for screening and diagnosis. Evaluation of the project has given rise to several findings and new research questions. Findings in this article illustrate the following evaluation issues: 1) studying the combination of strategies that are most effective and cost effective to notify workers of their disease risks, 2) determining the realistic yield from strategies to gain participation in health screening and other protective services for notified workers, 3) identifying the notification strategies that were most effective for different kinds of participants, 4) using process evaluation to identify key activities for ensuring continued participation of cohort members in screening, and 5) examining the extent to which participants are willing to quit smoking to protect their health.

Clinical study on urothelial tumors of dye workers in Wakayama City

Between January 1951 and December 31, 1990 urothelial tumors were detected in 112 of 1,085 male dye workers (10.3%) in Wakayama City who were formerly engaged in manufacturing of benzidine and/or beta-naphthylamine. The period from exposure to the chemicals to development of the tumor was a mean of 24.1 +/- 9.4 years. A peak incidence of urothelial tumors was observed also approximately 25 years after the peak period of manufacturing these intermediate products of dyes. The mean period from exposure to such carcinogenic chemicals to the onset of the disease was estimated to be 25 years. Of the 78 patients with primary bladder cancer diagnosed since 1969, 43 (55.1%) had tumors diagnosed mostly as a result of a positive urinary cytology test obtained as part of a screening program and 35 (44.9%) had tumors diagnosed as the result of symptoms. Ten patients (24.4%) in the screened group had been treated with total cystectomy by the last followup examination compared with 17 (50.0%) in the symptomatic group. The 10-year cumulative survival rates were significantly (p less than 0.05) higher in the screened patients (75.1%) than in the symptomatic patients (55.1%). Our results indicate that screening of high risk populations with urinary cytology tests is effective for early diagnosis and treatment of urothelial tumors, and it improves patient prognosis. Furthermore, the biological behavior of occupational urothelial tumors may be different from that of urothelial tumors in the general population.

[Occupational bladder tumors among persons subjected to carcinogenic amino compound exposure: the epidemiology and prevention]

The epidemiology of bladder tumors was examined among the subjects exposed to cancerogenic amino compounds such as beta-naphthylamine and benzidine (Group 1). The workers from other chemical shops of the plant were enrolled as a control group (Group 2); those from service shops (Group 3) and white-collar ones (Group 4) were also included. A total examined group comprised 4,624 subjects followed up in 1975-1979. The age- and sex-adjusted bladder tumor morbidity rates in males were 48.3, 11.0, 6.9 in Groups 1, 2, and 3, respectively (the normal rate, 5.6 per 100,000), while the respective figures in females were 75.0 and 18.2 in Groups 1 and 2, respectively (the normal rate, 1.1 per 100,000). No bladder cancer was recorded among the male workers from service shops and female service and white-collar workers (the expected rate was less than 1). Calculating the bladder cancer morbidity rates by the common standard indices indicated that there was no excess of the rates typical of the disease for males as compared to females, which is generally observed on exposure to potent cancerogenic substances. There was an increase in the latent period of urinary bladder cancer progression from 13.0 to 18.6 in males and to 20.4 in females who had been exposed to benzidine, as compared to the 1950s and 1960s. The mean latent period was 24.2 years in females and 21.5 in males who had been exposed to beta-naphthylamine. 42% of all those who had diagnosed bladder cancer had not come in direct contact with the above cancerogenic agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Drake Chemical Workers' Health Registry: coping with community tension over toxic exposures

BACKGROUND

Programs to communicate health risk information and to protect the health of groups exposed to toxic substances need to tailor interventions to the political, economic, and cultural situation of the at-risk group. In particular, such programs must often cope with exceptional community tension and conflict over these exposures.

METHODS

This article uses interviews and written materials to document and describe the state of affairs that led up to community tension over an occupational exposure to a bladder carcinogen. The article describes the planning and design of a program to provide medical surveillance to workers, which also alleviated community concern.

RESULTS

The Drake Chemical Workers' Health Registry coped successfully with community conflict and obtained a high participation rate.

CONCLUSIONS

General recommendations include the following: avoid identification with extraneous agendas; know the community and maintain communication; and match the intervention to the evolution of the community conflict.

Drake Chemical Workers' Health Registry Study: I. Notification and medical surveillance of a group of workers at high risk of developing bladder cancer

A medical surveillance program and epidemiologic study of 408 former workers of the Drake Chemical Company (now a Superfund waste site) was established in 1986. The Drake Health Registry Study was initiated because these workers had probable past exposures to beta-naphthylamine (BNA), a potent bladder carcinogen. The registry is widely viewed as a model for notification of workers at high risk of disease due to past occupational exposures. By the 40th month, 90% of the 366 living workers had been notified of the existence of the registry; 262 had been enrolled in the annual or semi-annual screening for bladder cancer. Among these, 27 persons have had abnormal screening results indicating moderate to high risk of bladder cancer and have been made eligible for further diagnostic tests. While no invasive bladder tumors were found among 18 persons completing the extended diagnostic evaluation, two diagnoses of moderate to severe dysplasia have been made. The registry has also identified three living and three deceased cases of bladder cancer in the cohort; a mortality analysis showed a 20- to 30-fold excess of bladder cancer. An incidence projection, based on the six identified cases, reveals that between six and ten new bladder cancer cases are likely to occur among the Drake cohort over the next 20 year period.

[Cancer mortality of male workers exposed to benzidine and/or beta-naphthylamine]

The risk of cancer was analysed in a cohort of 604 male workers who had been engaged in manufacturing and/or handling benzidine and/or beta-naphthylamine during the period 1945-71 at two factories located in the city of Osaka. The cohort was followed up from 1 January 1970 to the date of death or 31 December 1986. The mean follow-up time was 16.1 years. A total of 84 deaths was found compared with 112.66 expected based on the mortality of the Osaka population. Thirty-six were found to be dead of malignant neoplasms; 9 stomach, 2 colon, 1 rectum, 3 liver, 1 bile duct, 1 pancreas, 1 maxillary sinus, 6 lung, 8 bladder, and 2 ureter neoplasms as well as 1 case of myeloid leukemia. Seven cases were ascertained on death certificates as neoplasms of uncertain behaviour, all of which were tumors of genitourinary organs except for one case of brain tumor. Cancers of genitourinary organs and tumors of uncertain behaviour showed statistically significant increased standardized ratios (SMR = 12.20, 4.89). The mean age of death of those having genitourinary organs including cancer was 59 years old, and the latent period between the first exposure and the occurrence of the disease was 19.7 years on average. Non-significant increased risks of cancers of the colon, rectum, liver and lung were observed among the workers exposed to benzidine. Among the 7 histologically confirmed cases of these cancers, there were 2 adenocarcinomas of the lung, 1 adenocarcinoma of the rectum, 2 hepatocellular carcinoma and 1 adenocarcinoma of the bile duct. Seven patients with genitourinary tumors were found to have died of other primary cancers.

A protocol for bladder cancer screening and medical surveillance among high-risk groups: the Drake Health Registry experience

In 1986, the Drake Health Registry Study initiated bladder cancer screening for 366 persons at high risk because of occupational exposure to beta-naphthylamine. The Drake Health Registry Study screening protocol consists of urinalysis, Papanicolaou cytology, and quantitative fluorescence image analysis. A positive screening test qualifies participants for a full diagnostic evaluation. The screening protocol has been modified during the first 3 years of the program's existence to address unexpected patterns of test results and to incorporate advances in screening technology. The current protocol, which has a two-tiered screening schedule, has been utilized successfully for 15 months. Of the 26 positive results to date most have been based on abnormal Papanicolaou cytology and/or quantitative fluorescence image analysis. Bladder abnormalities were cited among most of the 18 study members who underwent diagnostic evaluation, including chronic cystitis, inflammation, hyperplasia, and dysplasia. We conclude that the screening program is detecting very early changes in a relatively young cohort and that these persons must be monitored over a number of years to ensure adequate medical surveillance.

[Occupation and urothelial cancer: the background and the clinical figure]

Occupational urothelial carcinomas which were developed by benzidine and beta-naphthylamine have been diagnosed and treated in 60 workers. The number of cases of bladder tumor, ureteral tumor and bladder with upper urinary tract tumor was 49, 2 and 9, respectively. Death from urinary tract carcinoma was 5 (8.3%) and 12 out of 60 died from other diseases, 8 from other organ carcinomas and 4 from none cancer diseases. Organ preserving therapy for occupational urinary tract carcinoma should be selected because of high recurrence tendency, especially cisplatin-radiation or BCG instillation therapy. In future, new candidates will decrease but the fact of the patients becoming older will be important including other organ carcinomas, when we follow them up. Case control study was done by examining replies to questions answered by non-tumor-developing group and tumor developing group. Questions included alcohol, water and cigarette consumption, working duration and difference of chemical substance. A statistically significant result was obtained only in difference of production or messenger of the chemical substance (p = 0.001).

[Occupational uroepithelial cancer: current status in Wakayama city and clinical study]

According to the records of Wakayama Labor Standard Office, at least 1,085 workers had been exposed to benzidine or beta-naphthylamine in the dyestuff factories in Wakayama City. By October 1988, 101 of them (9.3%) were confirmed to have urinary tract tumors. Including 2 other cases exposed in Osaka, a total of 103 cases of occupational uroepithelial cancer were studied here clinically. Site of tumors was bladder in 91 cases, renal pelvis in 2, ureter in 5 and papillomatosis type in 5. The age at the time of diagnosis ranged from 25 to 87 years with a mean of 53.8 years. The average latent period was 22.7 years, but the older the age of the worker at the start of exposure, the shorter was the latent period. In Wakayama, the proper system of healthy examination for chemical workers using urinary cytology was begun in 1970. Since then, more tumor cases have been discovered in comparison to the patients admitted with subjective symptoms of hematuria. The effectiveness of this group examination was significant in the incidence of total cystectomy in surgical treatment and in survival rate. In the comparative study between the groups of patients with occupational and spontaneous bladder cancer, the average age at diagnosis in the former was about ten years younger. Although the histological grade of tumor was not different between the two groups, the incidence of total cystectomy was lower and the survival rate was significantly higher in the occupational group.

[Present aspects and problems regarding occupational bladder cancer due to exposure to aromatic amines]

About a century has passed since the first case of bladder cancer due to occupational exposure to carcinogenic aromatic amines was reported. In the major developed countries of the world, it is forbidden to manufacture and/or to use such aromatic amines. In Japan in the 1950's, many workers were exposed to carcinogenic aromatic amines, but in 1972, the Labor Safety and Health Act came into force and manufacturing and/or using of four kinds of aromatic amines were forbidden. Recently it has been reported that the risk of bladder cancer in workers exposed to aromatic amines before the ban of these chemicals is approximately from several times to a hundred times compared with the general population, and some reports say that dose-response relationship was observed. The important issues now are the carcinogenicity of other kinds of aromatic amines besides benzidine and 2-naphthylamine, carcinogenicity of metabolites of several substances like synthetic dyes, and carcinogenic aromatic amines as impurities in substances imported from developing countries. The type of exposure to these carcinogens changes low level and long period exposures. In addition to the chemical or dye industries, an increased risk of bladder cancer was observed among workers handling leather and rubber and those engaged in printing, textile industries, hairdressing, truck driving and so on. In the future, it will be necessary to cooperate with the departments of epidemiology, toxicology and clinical medicine for the purpose of estimating the risk of these occupations and the health care administration of the exposed workers.

[Urothelial carcinoma related to exposure to aromatic amines]

Clinical and statistical observations were made on a group of 438 persons who had worked with aromatic amines (benzidine, 2-naphthylamine, 1-naphthylamine and dianisidine) with reference to their carcinogenic properties in the urinary tract. Urinary tract tumors developed in 68 (15.5%), with an average latent period of 22 years and 11 months. In these 68 cases, upper urinary tract tumors were found in 16 cases, 8 of which had bilateral lesions. The average age of onset was 48.1 ranging from 24 to 79. The incidence of tumors increased with the length of exposure to the amines. There was no finding that smoking habit increased the incidence of tumors in this group. Of the 49 new patients with bladder tumor, urine cytology was positive in 24 (49.0%) and suspicious of malignancy in 10 (20.4%), respectively. This indicated that it could be a useful screening test. Transurethral surgery was most frequently performed as an initial treatment. Recurrence occurred in 50 cases (73.5%), but 5-, 10- and 20-year-survival rates were 89.0 79.3 and 64.7%, respectively, showing a good prognosis. Malignant tumors in other organs developed in 18 (4.1%) of the 438 workers. The incidence of such malignant tumors was significantly higher in the workers who had been exposed to 2-naphthylamine than in others. Our data indicate that close observation is still necessary for early detection of patient with new or recurrent urothelial carcinoma in this group.

[Present status and background of occupational uroepithelial tumors]

The incidence of urothelial cancers in a group of 231 dyestuff plant workers who had been exposed to benzidine (BZ) or to beta-naphthylamine (BNA) was surveyed from 1962 to 1988. Fifteen out of 231 patients (6.5%) were found to have bladder cancer with the mean age at onset of 57.1 +/- 8.7 years. The estimated average period of engaging in this dyestuff exposure for these 15 patients was 92.4 +/- 47.3 months. The mean latent periods from the initial and last exposure until tumor development were 28.8 +/- 5.7 years and 16.6 +/- 7.0 years, respectively. Good negative correlation was observed between exposure periods and latent periods from the last exposure to onset (R = -0.06814). All 15 patients demonstrated tumors in the bladder, and one patient had a metachronous upper urinary tract cancer after treatment for bladder cancer. All tumors were histologically transitional cell carcinomas except for one adenocarcinoma. For initial treatment, five underwent total cystectomy, eight had transurethral resection (TUR) of the tumor, and one had partial cystectomy. Five out of 8 patients who had TUR have developed recurrent bladder tumors, and two of those patients underwent total cystectomy for second treatments. The mean follow-up period was 8.6 +/- 5.2 years, with two dying of cancer. For detection and monitoring, flow cytometric (FCM) analyses were available in five cases with bladder tumor and in two follow-up cases after bladder preserving treatments.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk for bladder cancer. Psychological impact of notification

Informing persons that they have been exposed to a carcinogenic chemical (beta-naphthylamine) may adversely affect these persons and their families. The purpose of this study was to identify and assess the psychological impact of a bladder cancer notification and screening program on persons at risk and their families. Approximately 140 subjects were randomly selected from 850 workers exposed to beta-naphthylamine. The Family APGAR, Impact of Event Scale, and Improved Readability Form of the Minnesota Multiphasic Personality Inventory were administered within four weeks of the initial medical screening and readministered six months later. Results show no evidence of disruption to families or substantive psychopathology among these persons. While the actual acquisition of cancer is undoubtedly a psychological trauma, mere notification of risk may not be traumatic in every situation.

[Some properties of aromatic amines]

The human carcinogenic activity of 4-4' amino diphenyl and 2 amino naphthalene, drew occupational physician's attention to "aromatic amines" as potentially carcinogenic compounds. The chemical-physical and biological properties of groups of products with structure very similar to them, show that the expression "aromatic amines" cannot define a class of compounds, but that it is necessary to consider only individual substances. The solutions carried out in industry for the replacement of some human cancerogenic products are reported.

Multiple primary cancers following exposure to benzidine and beta-naphthylamine

The incidence of second primary cancers has been ascertained in 3,322 employees who had worked from 1950 to 1978 in industries in Japan that manufactured benzidine and beta-naphthylamine. Of the 244 workers who had suffered from and died of cancer of the genitourinary organs (first primary cancer), 11 (all male) had subsequent primary, histologically confirmed cancers of the liver, gallbladder, bile duct, large intestine, and lung. A control group of 177 male bladder cancer patients, assembled from the Osaka Cancer Registry during 1965-1975, showed eight cases of a second primary, five being stomach cancer. No stomach cancer was observed in the study cohort. A statistically significant excess risk for liver, gall bladder, and bile duct cancer (p less than 0.05) was found The number of observed deaths from respiratory cancer was greater than expected, though not statistically significant. These findings appear to confirm previous clinical data suggesting an increased occurrence of multiple primary cancers in workers exposed to benzidine/beta-naphthylamine, pointing to a pluripotential action of these carcinogens.

Periodic urine cytology surveillance of bladder tumor incidence in dyestuff workers

The validity of urine cytology surveillance of occupational bladder tumor incidence was evaluated by reviewing the clinical history of nine bladder tumor cases found in dyestuff plant workers. A bladder tumor surveillance system has been organized for workers (179) active and 65 retired) who had been exposed to benzidine or beta-naphthylamine in the plant. The system consists of two-stage tests: periodic urine cytology as the first-stage screening test, followed by, in suspicious cases, urological examinations as second-stage tests. The urine cytology surveillance was found to be useful for two reasons: first, it detected tumors in five out of six cases surveyed by athe system, and second, four cases screened by cytology had tumors curable by transurethral operation, while other cases underwent cystectomy. Calculated average latent periods from the first and last exposure was 26.4 years (SD = 6.0) and 14.0 years (SD = 6.2), respectively. This time period indicates that the surveillance system should continue to be used for the exposed group even after workers have ceased being exposed.

Lymphocyte reactivity of workers exposed to carcinogenic and non-carcinogenic chemicals

Immunological studies have shown an increased lymphocyte reactivity in patients with early stage bladder cancer and individuals with pre-stage T1 exposed to bladder carcinogens (2-naphthylamine and industrial 1-naphthylamine containing 4-8% 2-naphthylamine) before 1952-that is, those at high risk of developing bladder cancer. Because of the close chemical similarity of Tobias acid (2-naphthylamine-1 sulphonic acid) to 2-naphthylamine, the lymphocytotoxicity of workers exposed to this chemical was investigated. The results show that the workers using Tobias acid unlike those exposed to 2-naphthylamine have lymphocytes with a normal range of reactivity towards bladder cancer cells, which is in keeping with the suggestion that Tobias acid is non-carcinogenic. The probable reason for its non-carcinogenicity is that the relatively very large size and hydropholic properties of the sulphonic acid group prevents enzymic action on the amino group by steric hindrance. The present lymphocytotoxicity results strengthens our earlier conclusion that the observed increased lymphocyte reactivity in workers exposed to bladder carcinogens is specific.