• cancer, haemophilia, leukemia, malignancy, prevalence, surveillance

Summary.  The prevalence of malignancies in US male patients with haemophilia, with or without concomitant viral infections, remains unknown. To estimate the prevalence of malignancy in US male patients with haemophilia. We investigated the prevalence of malignancies among male patients with haemophilia using data from a six-state haemophilia surveillance project. Case patients with malignancies were identified using International Classification of Diseases, 9th Revision, Clinical Modification codes abstracted from hospital records and death certificates during the surveillance period. Cancer prevalence rates were calculated for each year during the surveillance and compared with age- and race-specific prevalence rates among the U.S. male population obtained from the Surveillance, Epidemiology and End Results (SEER) Program. A total of 7 cases of leukaemia, 23 cases of lymphoma and 56 classifiable solid malignancies were identified among 3510 case patients during a total of 15 330 annual data abstraction collections. The rates of leukaemia, lymphoma and liver cancer among case patients were significantly higher than the rates among U.S. males as judged by prevalence ratios of 3.1 [95% confidence interval (CI) = 1.4–7.0] and 2.9 (95% CI = 1.8–4.6), respectively. In contrast, the prevalence ratio of prostate cancer was lower than expected at 0.49 (95% CI = 0.31–0.77). Overall the prevalence of most cancers among case patients was similar to that of the U.S. male population. However, patients with haemophilia who have unexplained symptoms should be evaluated for malignancy.