Examining Future Malignancies After a Secondary Myelofibrosis

A recent study examined the association between patients with secondary myelofibrosis (SMF) and later development of nonhematological second primary malignancies (SPM). While SPMs are known to occur at a higher rate in patients with myeloproliferative neoplasms (MPN), information is limited about whether or not it occurs after a secondary myelofibrosis.

Polycythemia vera (PV) and essential thrombocythemia (ET) are 2 types of MPNs that can progress to post‐PV (PPV) myelofibrosis (MF) and post‐ET (PET) MF, generally referred to as SMF.

The 10‐year cumulative incidence of nonhematological SPM among 20,250 patients with MPN included in the Surveillance, Epidemiology, and End Results Program database was 12.7%, higher than that expected in the general US population.

This study sought to establish the incidence of SPMs, the relationship between SPMs and SMF occurrence in PV and ET, and address the effect of Janus kinase (JAK) inhibitors on SPM occurrence. Researchers included 2233 patients, separated into 2 groups: the MYSEC cohort of 781 patients with SMF, and the Pavia cohort of 611 patients with PV and 841 patients with ET.

In the MYSEC cohort, after a median follow-up of 14.8 years from initial PV or ET diagnosis, 55 (7%) patients had an SPM; 8 had no available date of SPM and were excluded from the time-dependent analysis, 22 (46.8%) had an SPM during the ET or PV phase, and 25 (53.2%) had an SPM after transformation to SMF.

The incidence of SMP after SMF diagnosis was 0.98 for every 100 patient-years. When factoring in nonmelanoma skin cancer, the incidence of SPM after SMF diagnosis rose to 1.56 per every 100 patient-years.

When the MYSEC and Pavia cohorts were combined, there was no significant difference in SPM incidence between patients whose disease evolved to SMF and those whose disease did not (P = .06). In patients with SMF, JAK inhibitor treatment was only associated with nonmelanoma skin cancer recurrence (P = .02), which may be from the use of hydroxyurea first or later JAK inhibitor treatment. Physicians should monitor cutaneous cancers before and during JAK inhibitor treatment, the researchers wrote.

These findings highlight the need of studies aimed at identifying MPN patients at higher risk of SPM, the authors wrote, and that future research should aim to identify patients at higher risk of secondary primary malignancies.

Reference

Mora B, Rumi E, Guglielmelli E, et al. Second primary malignancies in postpolycythemia vera and postessential thrombocythemia myelofibrosis: A study on 2233 patients [published online June 7, 2019]. Cancer Med. doi: 10.1002/cam4.2107.