Second primary malignancies in chronic myeloid leukemia

Survival of patients with chronic myeloid leukemia (CML) has improved with the use of imatinib and other tyrosine kinase inhibitors. There is limited data on second primary malignancies (SPM) in CML. We analyzed the SPMs rates among CML patients reported to Surveillance, Epidemiology, and End Results (SEER) database during pre-(1992-2000) and post-(2002-2009) era. We used SEER Multiple Primary-Standardized Incidence Ratio session to calculate standardized incidence ratios (SIRs). Among 8,511 adult CML patients, 446 patients developed 473 SPMs. The SIR for SPMs in CML patients was significantly higher with observed/expected ratio:1.27, P < 0.05 and absolute excess risk of 32.09 per 10,000 person years compared to general population. The rate of SPMs for cancers of all sites in post-imatinib era were significantly higher compared to pre-imatinib era with observed/expected ratio of 1.48 versus 1.06, P = 0.03. This study showed that risk of SPMs is higher among CML patients. The risk of SPMs is significantly higher in post-imatinib era compared to pre-imatinib era.