Objectives: The aim of this work is to investigate the association between transfusion history and cancer mortality in a prospective follow-up study.
Methods: We conducted a prospective cohort study in four areas of Akita Prefecture, Japan, in 10,451 individuals (4,401 men and 6,050 women, aged 40-79 years) without history of cancer. The subjects were followed until 31 December 2003 and the number of deaths from cancer was recorded.
Results: After mean follow-up of 12.76 years (140,259 person-years), 520 individuals (333 men and 187 women) died of cancer. History of blood transfusion before 1990 was mildly but significantly associated with overall cancer mortality (hazard ratio = 1.75, 95% confidence interval: 1.32-2.18) and nonliver cancer mortality (HR = 1.68, 95% CI: 1.25-2.26). This significant association remained unchanged after excluding deaths that occurred within 5 years of baseline for overall cancer mortality (HR = 1.47, 95% CI: 1.04-2.09) and for nonliver cancer mortality (HR = 1.43, 95% CI: 1.00-2.04). The significant association for nonliver cancer mortality was confirmed in subjects with no smoking history and/or alcohol consumption (HR = 2.01, 95% CI: 1.35-3.00). Site-specific analysis showed a possible association between transfusion history and death from pancreatic cancer.
Conclusions: History of blood transfusion before 1990 was found to be associated with increased risk for cancer mortality and was independent of liver diseases. The mechanism of the association between blood transfusion and cancer mortality warrants further research.