1. ¹CPO – Registro Tumori Piemonte, via San Francesco da Paola 31, 10123 Turin, Italy
2. ²Escuela Andaluza de Salud Pública, Registro de Cáncer de Granada, Campus de Cartuja, Apdo. Correos 2070, 18080 Granada, España
3. ³Departamento de Ciencias Sociosanitarias, Facultad de Medicina Universidad de Sevilla, Avda. Sanchez Pizjuán s/n 41009, Sevilla, España
4. ⁴Registo Oncológico Regional Sul, Instituto Portugûes de Oncologia, Rua Prof. Lima Basto, 1093 Lisboa, Portugal
5. ⁵Registre des Tumeurs du Doubs, Faculté de Médecine-Pharmacie, Place Saint Jacques, 25030 Besançon Cédex, France
6. ⁶Instituto de Oncología 'A.H. Roffo', Av. San Martín 5481, 1417 Buenos Aires, Argentina
7. ⁷Dermatology Clinic, Slotsgade 14 A, 3400 Hillerød, Denmark
8. ⁸Krankenhaus Buxtehude, Dermatologisches Zentrum, Am Krankenhaus 1, Buxtehude, Germany
9. ⁹Consejería de Sanidad y Consumo, Servicio de Epidemiología, Ronda de Levante 11, 30008 Murcia, España
10. ¹⁰Clinica Dermatologica Università 'Federico II' Azienda Universitaria Policlinico, via S. Pansini 5, Edificio 10, Napoli, Italy
11. ¹¹Ospedale degli Infermi di Biella, via Caraccio, Dermatologia, Biella, Italy
12. ¹²Epidaure, Rue des Apothicaires, Parc Euromédecine, 34298 Montpellier, France
13. ¹³Lega Italiana per la lotta contro i tumori Sezione provinciale Ragusa, via Traspontino 1, 97100 Ragusa, Italy
14. ¹⁴Dipartimento di Dermatologia, Università di Firenze, via della Pergola 58/60, 10121 Firenze, Italy
15. ¹⁵Istituto per lo Studio delle Macromolecole (ISMAC), Consiglio Nazionale delle Ricerche (CNR), Corso G. Pella 16, 13900 Biella, Italy

Correspondence: Dr R Zanetti, E-mail: roberto.zanetti@cpo.it

¹⁶Helios Working Group members are listed in Appendix A.

Received 31 October 2005; Revised 6 January 2006; Accepted 13 January 2006; Published online 21 February 2006.

Abstract

We directly compared risk factors between 214 histologically confirmed melanomas (CMM), 215 basal-cell carcinomas (BCC) and 139 squamous-cell carcinomas (SCC) in a multiple case–case–control study with 349 controls from patients without dermatological disease admitted to the same hospitals. Subjects with fair hair had a significant risk increase for all types of tumours at a comparable level (OR_adj for blonde hair: CMM 2.3; SCC 2.4; BCC 2.3). The effect of pale eyes was significant and similar for CMM and BCC (OR_adj 2.6). Intermittent sun exposure measured in hours spent at beach during holidays was significant for both CMM (OR_adj 2.6 for more than 7000 lifelong hours) and BCC (OR_adj 2.1 for more than 7000 lifelong hours), while SCC exhibited a significant risk increase for chronic exposure to sunlight measured in hours of outdoor work (OR_adj 2.2 for more than 6000 lifelong hours). In the case–case comparison using a multinomial logistic regression model, we found a statistically significant risk difference for pale eyes, and number of naevi in the CMM group, compared to other skin cancers. For intermittent sun exposure, there was a significant risk difference of BCC when compared to the risk of SCC. Factors influencing risk of SCC are different, with chronic exposure to sun playing a major role in causing this type of carcinoma.