J K Straughan1, T Sorahan. 1. British Rubber Manufacturers' Association Health Research Unit, Scala House, Holloway Head, Birmingham B1 1EQ, UK.
Abstract
OBJECTIVES: To monitor the occurrence of stomach and lung cancer in a newly defined cohort of United Kingdom rubber workers and to report findings for other cancers in an early period of follow up. METHODS: A prospective cohort of 9031 male and female workers from 42 United Kingdom rubber factories has been enumerated. All employees had a minimum of 12 months employment and were first employed at one of the participating factories in the period 1982-91. Mortality data were available for the period 1983-98 and cancer registration data for the period 1983-94. The mortality and cancer incidence experienced by the cohort were compared with expected values based on national rates defined by period, age, and sex. RESULTS: Mortality from lung cancer was close to expectation (men: observed (obs) 11, expected (exp) 12.70, standardised mortality ratio (SMR) 87, 95% confidence interval (95% CI) 43 to 155; women: obs 0, exp 1.34, SMR 0, 95% CI 0 to 275). Mortality from stomach cancer was unexceptional (men: obs 1, exp 2.69, SMR 37, 95% CI 1 to 207; women: obs 0, exp 0.24, SMR 0, 95% CI 0 to 1537). Many statistical comparisons were made both for mortality data and for cancer registration data; only one difference between observed and expected numbers was significant (mortality from cancer of the testis: obs 3 exp 0.51, SMR 589, 95% CI 122 to 1722). Corresponding findings for incident cancers of the testis were unexceptional (obs 5, exp 5.13, standardised registration ratio (SRR) 97, 95% CI 32 to 227). CONCLUSION: The findings should be treated with caution as they relate to an early period of follow up. Nevertheless, they hold out the prospect that the increased SMRs for stomach and lung cancers reported for historical cohorts of United Kingdom rubber workers may not be apparent in more recent cohorts.
OBJECTIVES: To monitor the occurrence of stomach and lung cancer in a newly defined cohort of United Kingdom rubber workers and to report findings for other cancers in an early period of follow up. METHODS: A prospective cohort of 9031 male and female workers from 42 United Kingdom rubber factories has been enumerated. All employees had a minimum of 12 months employment and were first employed at one of the participating factories in the period 1982-91. Mortality data were available for the period 1983-98 and cancer registration data for the period 1983-94. The mortality and cancer incidence experienced by the cohort were compared with expected values based on national rates defined by period, age, and sex. RESULTS: Mortality from lung cancer was close to expectation (men: observed (obs) 11, expected (exp) 12.70, standardised mortality ratio (SMR) 87, 95% confidence interval (95% CI) 43 to 155; women: obs 0, exp 1.34, SMR 0, 95% CI 0 to 275). Mortality from stomach cancer was unexceptional (men: obs 1, exp 2.69, SMR 37, 95% CI 1 to 207; women: obs 0, exp 0.24, SMR 0, 95% CI 0 to 1537). Many statistical comparisons were made both for mortality data and for cancer registration data; only one difference between observed and expected numbers was significant (mortality from cancer of the testis: obs 3 exp 0.51, SMR 589, 95% CI 122 to 1722). Corresponding findings for incident cancers of the testis were unexceptional (obs 5, exp 5.13, standardised registration ratio (SRR) 97, 95% CI 32 to 227). CONCLUSION: The findings should be treated with caution as they relate to an early period of follow up. Nevertheless, they hold out the prospect that the increased SMRs for stomach and lung cancers reported for historical cohorts of United Kingdom rubber workers may not be apparent in more recent cohorts.