Second Cancers After Autologous Stem-Cell Transplantation

High-dose chemotherapy (HDT) followed by autologous hematopoietic stem-cell transplantation (ASCT) can cure patients with relapsed lymphoma, but the treatment carries a risk for second primary malignancies (SPMs).

To determine the risk for SPMs, other than lymphoma-related malignancies, among patients who underwent HDT-ASCT, investigators conducted a retrospective, population-based, cohort study of 803 individuals in the Danish Lymphoma Registry with a history of aggressive lymphomas. Most patients had received only one line of therapy prior to HDT-ASCT, and 15% had received radiotherapy. The study excluded those who had primary central nervous system lymphoma, HIV-positivity, prior organ transplantation, or other malignancy prior to ASCT. Each participant was matched with five sex- and birth-year-matched controls from a general-population registry.

During a median 7.76 years of follow-up, a higher percentage of patients than controls had developed SPMs (16% vs. 11%; hazard ratio, 2.1; P<0.0001). Patients had significantly higher risk for myelodysplastic syndrome or acute myeloid leukemia (HR, 41.13) and for non-melanoma skin cancer (HR, 2.94), but not for solid tumors. The 10-year risk for SPMs was higher for patients than for controls (20% vs. 14%). A secondary analysis — comparing study patients who underwent HDT-ASCT with a cohort of lymphoma registry patients who did not undergo the treatment — showed that, at a median follow-up of 6.32 years, those who underwent HDT-ASCT had a higher risk for SPMs (HR, 1.58; P<0.0054).