Secondary Solid Cancers Among Patients with Philadelphia Chromosome-Negative Myeloproliferative Neoplasms: A Multicenter Study.

Objective: We investigated the occurrence and characteristics of secondary solid cancers (SSC) in Philadelphia chromosome-negative myeloproliferative neoplasm (Ph- MPN) patients from Türkiye. We identified the potential risk factors for SSC development including the impact of cytoreductive therapies and assess the influence of SSC on patient survival.

Material and methods: 1013 Ph- MPN patients diagnosed between 1995 and 2022 was retrospectively analyzed. Data related to demographics, clinical and laboratory parameters, SSC development, cytoreductive therapy exposure and survival outcomes were collected. Statistical analyses were performed using SPSS 26.0 software.

Results: Of the Ph- MPN patients, 6.6% developed SSC, with carcinoma being the most common type. Older age at Ph- MPN diagnosis and male gender were associated with SSC occurrence. Ph- MPN patients diagnosed with SSC and patients with no diagnosis of SSC showed no significant difference for complete blood count, spleen size, Ph- MPN diagnostic groups and driver mutation frequencies. However, SSC patients showed a higher frequency of arterial thrombosis and tendency towards increased rate for total thrombosis (p=0.030, p=0.069; respectively). In multivariate analysis, arterial thrombosis was the sole independent risk factor and interferon (IFN)-based therapy the sole protective factor for SSC development. Median overall survival (OS) did not differ between patients with and without SSC except for polycythemia vera (PV) patients with SSC, who had shorter OS (175±15 and 321±26 months, respectively; p = 0.005).

Conclusion: Our study highlights the prevalence and characteristics of SSC in Turkish patients diagnosed with Ph- MPN. Arterial thrombosis was associated with increased SSC risk while IFN-based therapy offered potential protection from SSC. Screening for SSC in Ph- MPN patients with arterial thrombosis may be relevant. These findings emphasize the importance of malignancy screening in Ph- MPN patients, especially in high-risk subgroups and call for further research to elucidate the underlying mechanisms and optimize treatment strategies.