Merk K (Department of General Oncology, Karolinska Hospital, Stockholm, Sweden), Mattsson B, Mattsson A, Holm G, Gullbring B and Björkholm M. The incidence of cancer among blood donors. International Journal of Epidemiology 1990, 19: 505–509.
This study presents data on cancer incidence among 37 795 blood donors in an attempt to test the hypothesis that blood donation might be associated with cancer development. At a median follow-up time of nine years (range 5–13 years) a total of 1152 cancer cases have been diagnosed. The expected number of cancer cases derived from an age-matched population was 1459 giving a relative risk ratio (RR) of 0.79 (p<0.001). Calculations were made with and without latency periods between first blood donation and the diagnosis of cancer (0, 5, 10, 15 years). Overall, significantly decreased cancer incidence was observed (p<0. 001) though the number of observed cases of haematological malignancies was not significantly different from that expected. For polycythaemia vera, however, the O/E ratio was 1.81 possibly indicating an association with blood donation. A more likely explanation is that this reflects increased diagnosis of polycythaemia vera in the blood donor population.