Pb1910: chronic myeloid leukemia and relationship to secondary solid neoplasms

Background: Chronic Myeloid Leukemia (CML) is a myeloproliferative neoplasm whose first-line treatment involves Tyrosine Kinase Inhibitors (TKI), that have improved the prognosis of the disease after its introduction, with a gain in the overall survival of these patients. In patients in the chronic phase of the disease, the most common cause of death is associated with other neoplasms, which raises the hypothesis that the observed mortality could be the result of a carcinogenic effect of tyrosine kinase inhibitors. Since studies to date have had contradictory results, this work aims to assess the risk of developing secondary solid neoplasms (NSS) in patients with CML. Aims: This study aims to assess the risk of developing SSN in patients with CML. Methods: Patients with positive BCR-ABL transcripts were analysed in a University Hospital Center between 01/01/2008 and 15/02/2022. Results: Sample of 69 patients (53.6% women) all in the chronic phase at diagnosis. Median age 53 years (23-85 years). In the first therapeutic line, most of them underwent TKI (91.3% underwent Imatinib and 5.7% underwent nilotinib). In the total sample, 69.5% needed only 1 therapeutic line. Eight (11.6%) died, only in 2 cases the death was related to CML. Nine patients (11.9%) developed SSN, a majority men (n=8, 88.9%) with a median age of 69 years (57-74 years) at diagnosis. All of them were diagnosed between 14 and 121 months. The majority of patients had gastrointestinal cancer (n=4, 44.4%), followed by prostate cancer (n=3, 33.3%), head and neck cancer (n=1, 11.1%) and lung cancer (n=1, 11.1%). All were exposed to TKI and Imatinib was common to all. Two patients died due to SSN, corresponding to 25% causes of death in the total study sample. When statistically comparing the occurrence of SSN with the time between the diagnosis of CML and the second neoplasm or the duration of the different therapeutic lines, there was no correlation with statistical significance (p>0.05). Summary/Conclusion: SSN appeared in about 12% of patients with CML. Contrary to what is described in the literature, the sample of patients with SSN is mostly made up of older men. As the risk of developing neoplasms in the general population is greater in the elderly, the development of cancer in these patients can be considered to be similar to that in the general population. The greatest risk for the development of SSN is described in the 1st year after the diagnosis of CML, which was not verified in our study. As limitations of the study the authors highlight the reduced sample as well as the need for a longer follow-up period.