Odds ratios cancers

In a case-control study of the relation between occupational exposures to various suspected estrogenic chemicals and the occurrence of breast cancer, the breast cancer odds ratio (OR) was not elevated above unity (OR=0.8 95% 01=0.2-3.2) for occupational exposure to endosulfan compared to unexposed controls (Aschengrau et al. 1998) however, the sample sizes were very small (three exposed seven not exposed), and co-exposure to other unreported chemicals also reportedly occurred. Both of these factors may have contributed to the high degree of uncertainty in the OR indicated by the wide confidence interval. 

In a nested case-control study of cancers associated with chemical exposures in the wood industry, Kauppinen et al. (1986) found a significantly increased risk of respiratory system cancer associated with exposure to phenol and phenol in wood dust. As is often the case in occupational settings, these exposures were confounded by smoking and exposures to other materials like pesticides. The increased risk observed for exposure to phenol was almost 5-fold (odds ratio of 4.94), but showed no dose-related increase. This risk dropped to 4-fold with adjustments for smoking history, and to less than 3-fold (and non-significant) when workers exposed to both phenols and pesticides were excluded from the analysis. 

In humans, cases of hepatomas have appeared years after acute exposure to carbon tetrachloride, however, none of the cases could establish a causal link between the exposure and development of neoplasms." Epidemiological studies have also given inconclusive results. A cancer mortality study of a population of rubber workers reported a significantly elevated odds ratio relating carbon tetrachloride with lymphatic leukemia, and lymphosarcoma and reticulum cell carcinoma." A recent retrospective cohort mortality study of aircraft maintenance workers found an increased risk of... 

Selected characteristics were compared between cases and controls by using test. The analyses of data were performed using the computer software SPSS for Windows version 11.5. Max type 1 error was accept as 0.05. Binary logistic regression was performed to calculate the odds ratios (ORs), and 95% confidence intervals (Cls) to assess the risk of breast cancer. 

In an abstract, Freudenheim et al. (1997) presented the results of a study conducted in western New York, United States, on 134 premenopausal and 181 postmenopausal cases of breast cancer and 356 population controls. Heavy alcohol intake was associated with an increased risk for premenopausal breast cancer (odds ratio, 3.5 95% CI, 1.3-9.2) among ADHj subjects but not among women with ADHj or ADH32-2 genotypes. This association was not observed for postmenopausal breast cancer. 

A nested case-control study within a cohort of rubber workers in the United States was performed to examine the relationship between exposure to solvents and the risk of cancer (Checkoway et al., 1984 Wilcosky et al., 1984). The cohort consisted of 6678 male rubber workers who either were active or retired between 1964 and 1973. The cases comprised all persons with fatal stomach cancer (n = 30), respiratory system cancer (z7 = 101), prostate cancer ( = 33), lymphosarcoma (n = 9) or lymphocytic leukaemia (z7 = 10). These sites were chosen because they were those at which cancers had been found to be in excess in an earlier cohort analysis (McMichael et al., 1976). The controls were a 20% age-stratified random sample of the cohort (z = 1350). Exposure was classified from a detailed work history and production records. An association was observed between exposure for one year or more to carbon tetrachloride and lymphocytic leukaemia (odds ratio (OR), 15.3 / < 0.0001, based on eight exposed cases) and lymphosarcoma (OR, 4.2 p < 0.05, based on six exposed cases) after adjusting for year of birth. The relative risk associated with 24 solvents was examined and levels of exposure were not reported. [The Working Group noted that overlapping exposures limit the ability to draw conclusions regarding carbon tetrachloride.]... 

Bond et al. (1986) conducted a nested case-control study of lung cancer among a cohort of 19 608 male chemical workers in the United States (Bond et al., 1985). Further details of the study are reported in Section 2.2 of the monograph on carbon tetrachloride in this volume. Ever having been exposed to epichlorohydrin was associated with a decreased risk of lung cancer (odds ratio, 0.3 95% CI, 0.1-0.9 5 exposed cases). 

In Siemiatycki s (1991) population-based case-control study of cancer in Montreal, Canada (see monograph on dichloromethane in this volume), phenol was one of the substances evaluated 1% of the entire study population had been exposed to it at some time. Among the main occupations to which phenol exposure was attributed in this study were electric motor repairmen and foundry workers. The publication reported an association between phenol and pancreatic cancer (odds ratio, 4.8 90% CI, 1.8-12.7 n = 4) for no other site was cancer risk associated with phenol exposure. [The Working Group noted that detailed results for other sites were not provided, because they were based on small numbers, and that workers typically had multiple exposures.]... 

---