1. ¹Childhood Cancer Research Group, 57 Woodstock Rd, Oxford OX2 6HJ, UK
2. ²Centre for Epidemiology and Biostatistics, University of Leeds & Northern and Yorkshire Cancer Registry and Information Service, Arthington House, Hospital Lane, Leeds LS16 6QB, UK
3. ³Division of Population Studies and Human Genetics, Queensland Institute of Medical Research, Post Office, Royal Brisbane Hospital, QLD 4029, Australia

Correspondence: Dr RE Neale, E-mail: rachel.neale@ccrg.ox.ac.uk

Received 12 April 2005; Revised 22 June 2005; Accepted 20 July 2005; Published online 16 August 2005.

Abstract

In a registry-based case–control study, we compared the site-specific occurrence of nonmelanoma (keratinocytic) skin cancers among patients with cutaneous melanoma cases (cases, n=3774) and solid tumours (controls, n=349 923), respectively. Overall, patients with melanoma were almost five-fold more likely to develop keratinocytic cancers compared with solid tumour controls (adjusted OR 4.7, 95% CI 4.1–5.3), but the risks varied depending upon the site of melanoma. Whereas patients with melanoma of the head and neck had similarly increased risks of keratinocytic cancers across all body sites, patients with melanoma of the trunk were significantly more likely to develop keratinocyte cancer diagnosed on the trunk (adjusted OR 12.5, 95% CI 7.2–20.2) than on the head and neck (adjusted OR 3.0, 95% CI 2.2–4.3). Similar colocalisation of skin tumours was observed for patients with melanomas of the lower limb. These findings provide support for the hypothesis that skin cancers at different anatomical sites may arise through different causal pathways.