Cancer incidence in healthy Swedish peripheral blood stem cell donors

Granulocyte colony-stimulating factor (G-CSF) has been used for over 20 years to obtain peripheral blood stem cells from healthy donors for allogeneic stem cell transplantation. Concerns have been raised about a potentially increased cancer incidence in donors after donation, especially regarding haematological malignancies. In a prospective Swedish national cohort study, we studied the cancer incidence after donation in 1082 Swedish peripheral blood stem cell donors, donating between 1998 and 2014. The primary objective was to evaluate if the cancer incidence increased for donors treated with G-CSF. With a median follow-up time of 9.8 years, the incidence of haematological malignancies was 0.85 cases per 1000 person-years, and did not significantly differ from the incidence in age-, sex- and residence-matched population controls (hazard ratio 1.70, 95% confidence interval (CI) 0.79-3.64, p value 0.17), bone marrow donors or non-donating siblings. The total cancer incidence for peripheral blood stem cell donors was 6.0 cases per 1000 person-years, equal to the incidence in matched population controls (hazard ratio 1.03, 95% CI 0.78-1.36, p value 0.85), bone marrow donors or non-donating siblings. In this study of healthy peripheral blood stem cell donors, the cancer incidence was not increased after treatment with G-CSF.