Occupations of parents of children with retinoblastoma: a report from the Children's Cancer Study Group.

A matched case-control study was conducted by the Children's Cancer Study Group to investigate the role of parental occupation in the etiology of sporadic heritable and nonheritable retinoblastoma. Eligible cases were those patients with retinoblastoma diagnosed in 1982-1985 at any of the Children's Cancer Study Group member hospitals. Telephone interviews of 201 parents of cases and their pair-matched controls selected by random digit dialing were completed. Of the 201 cases, 19 were familial, 67 were sporadic heritable, and 115 were nonheritable. The 19 familial cases were excluded from the analysis. Paternal employment in the military [odds ratio (OR) 2.8, 95% confidence interval (CI) 1.1-8.8, P = 0.04] and in the metal industry (OR infinity, 95% CI 1.4-infinity, P = 0.02) was associated with sporadic heritable retinoblastoma (N = 67). For nonheritable retinoblastoma (N = 115), a significant association was observed for a job cluster consisting mostly of welders and machinists (OR 4.0, 95% CI 1.1-22.1, P = 0.04). Occupations of maternal grandparents were also studied and an association was observed with farming and nonheritable retinoblastoma (OR 10.0, 95% CI 1.4-433, P = 0.02). Many comparisons were made and the number of significant findings did not exceed that expected by chance. Thus, the results need to be interpreted very cautiously. However, the findings related to metal exposure corroborate observations on other childhood cancers.