An updated investigation of cancer incidence and mortality at a Scottish semiconductor manufacturing facility with case-control and case-only studies of selected cancers
- Andrew Darnton1,
- Brian G Miller2,
- Laura MacCalman2,
- Karen S Galea2,
- Sam Wilkinson1,
- John W Cherrie2,
- Amy Shafrir2,
- Damien McElvenny3,
- John Osman1
- 1Health and Safety Executive, Epidemiology Unit, Bootle, Merseyside, UK
- 2Institute of Occupational Medicine, Research Avenue North, Riccarton, Edinburgh, UK
- 3University of Central Lancashire, School of Health, Preston, Lancashire, UK
- Correspondence to Andrew Darnton, Health and Safety Executive, Epidemiology Unit, Redgrave Court, Merton Road, Bootle, Merseyside L20 7HS, UK;
- Accepted 21 May 2012
- Published Online First 19 June 2012
Objectives An earlier investigation raised concern that some cancer cases might be linked to work at a semiconductor manufacturing plant. The aim of this study was to describe an update of the cancer incidence and mortality of these workers and assess whether workplace exposures contributed to any increased risk of selected cancers.
Methods Standardised mortality ratios and standardised incidence ratios were calculated for cancer site groups of a priori interest in a cohort previously flagged against the National Health Service Central Register, with follow-up extended to the 2007 for deaths and 2006 for cancer registrations. Cases of female breast cancer, lung and stomach cancer, and male brain cancer, and a random sample of control subjects individually age-matched to the breast cancer cases, were identified from within the cohort dataset and invited to participate via General Practitioners. Exposures were estimated using a job exposure matrix developed from a historical hygiene assessment and assigned to job histories obtained from personal interview of subjects (or proxies).
Results Though the findings were uncertain, there were no excesses of mortality or cancer incidence, either overall or for specific cancer sites, suggestive of a workplace effect. Logistic regression analyses comparing 20 cases of breast cancer with 83 matched controls showed no consistent evidence of any relationship with occupational exposures. Assessment of commonalities of workplace exposures among case sets for other cancer types was limited by the small numbers.
Conclusions These results do not support earlier concerns about occupational cancer risks among this cohort.
Funding Health and Safety Executive.
Competing interests None.
Ethics approval Ethics approval provided by West of Scotland Research Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.