Standard incidence ratio

An update of a previous study (Axelson et al. 1978), Axelson (1986) evaluated an expanded cohort of 1,424 men (levels of trichloroethylene exposure inferred from measured urinary metabolite concentrations) and found a significant increase in incidences of bladder cancer and lymphomas, and a lower than expected incidence of total cancer mortality. A further update of this work (Axelson et al. 1994) expanded the cohort to include 249 women, tracking cancer morbidity over 30 years, and found no correlation between exposure concentration or exposure time and cancer incidence at any site. The highest standardized incidence ratio noted in this study was 1.56 (95% Cl of 0.51-3.64) for 5 cases of non-Hodgkin s lymphoma observed in men. Although four of these cases occurred in persons exposed for at least 2 years, and 3 cases had a latency of 10 years or more, urinary levels of TCA showed that 4 of the 5 cases were exposed to the lowest levels of trichloroethylene (urinary levels of TCA 0-49 mg/L). The study authors mentioned that a urinary TCA level below 50 mg/L corresponds to a trichloroethylene exposure concentration of about 20 ppm. The study authors concluded that "this study provides no evidence that trichloroethylene is a human carcinogen, i.e., when the exposure is as low as for this study population."... 

PEL Pg pmol PHS PMR ppb ppm ppt REL RfD RTECS sec SCE SIC SIR SMR STEL STORET TLV TSCA TRI TRS TWA u.s. UF yr WHO wk permissible exposure limit picogram picomole Public Health Service proportionate mortality ratio parts per billion parts per million parts per trillion recommended exposure limit Reference Dose Registry of Toxic Effects of Chemical Substances second sister chromatid exchange Standard Industrial Classification Standardized incidence ratio standard mortality ratio short term exposure limit STORAGE and RETRIEVAL threshold limit value Toxic Substances Control Act Toxics Release Inventory total reduced sulfur time-weighted average United States uncertainty factor year World Health Organization week... 

Previous lARC overall evaluations of carcinogenicity are given in parentheses. N, number SMR, standardized mortality ratio SIR, standardized incidence ratio... 

A possible relation between systemic glucocorticoid use and a risk of esophageal cancer has been described in a population-based study in Denmark, in which the prescriptions database and the Danish cancer registry were linked (365). There was an increase in the number of cases observed (n = 36) compared with the number expected (n = 19), with a standardized incidence ratio of 1.92 (95% Cl = 1.34, 2.65). 

There is, however, a possibility that an increased risk of breast cancer might be associated with the state of infertility itself and not with the agents administered to treat it. In a retrospective study of data on 12 193 women evaluated for infertility between 1965 and 1988 at five clinical sites, 292were identified and followed up to the end of 1999. The standardized incidence ratios for in situ and invasive breast cancers in these women were compared with the breast cancer risks in a cohort from the general population (62). Infertile patients as a group had a significantly higher risk of breast cancer (RR = 1.29, 95%CI... 

The incidence of cancer among 803 Danish workers exposed to trichloroethylene has been evaluated (1). There was no overall increase. However, the standardized incidence ratio was significantly higher in men with non-Hodgkin s lymphoma or esophageal cancer and in women with cervical cancer. 

Non-systemic end-stage renal disease - Glomerulonephritis or interstitial nephritis Standard incidence ratio 4.22 (1.54-9.19)... 

To compare the incidence or mortality for a disease of interest between two populations, the data are adjusted to allow for differences between the two populations with respect to age, gender, race, and other variables. The adjustment may be direct or indirect. The reader is referred to WHO (1999) for a description of the two methods. The indirect method, which is more commonly used, generates measures of association known as standardized mortality ratios (SMRs) and standardized incidence ratios (SIRs). These ratios compare the mortality or incidence for the disease of interest in the population of interest with that which would be expected based on an external population. 

Standardized incidence ratio used when the expected cancer number is obtained from a registry... 

Abbreviations ALAD, delta-aminolevulinic acid dehydratase CBLI, cumulative blood lead index HR, hazard ratio NHANES, National Health and Nutrition Examination Survey (II = second survey, HI = third survey) OR, odds ratio OSHA, Occupational Safety and Health Administration PLEA, petrol-lead emission area RR, relative risk SE, standard error, SIR, standardized incidence ratio SMR, standardized mortality ratio. 

Table 3. Standardized incidence ratio (SIR) and 95 % confidence interval of cancer at different sites in patients with achlorhydria or decreased acid secretion g... 

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