Treatments for essential thrombocythemia (ET) comprising of hydroxyurea (HU) and alkylating agents (ALK) did not appear to impact development of secondary malignancies in patients with ET, according to a report in Cancer Medicine.

Essential thrombocythemia is a myeloproliferative neoplasm occurring most frequently in the elderly. Treatment of choice is cytoreduction with hydroxyurea. Other treatments that have been used and are indicated for some high-risk patients include alkylating agents, α-interferon (IFN), and anagrelide (ANA).

However, some reports on the long-term safety of HU and ALK have been concerning. Therefore, these researchers sought to determine the effects of different treatments on the development of secondary malignancies in patients with ET.

For the study, the researchers evaluated the influence of treatment on development of secondary malignancies in a real-life cohort of 1026 patients with ET. The study cohort was divided into 5 groups based on treatment: group 0 had no treatment; group 1 was treated with HU; group 2, with ALK; group 3, with ALK + HU sequentially or in combination; and group 4, with ANA and/or IFN only. Patients in groups 1, 2, and 3 could also have a history of treatment with ANA and/or IFN because these drugs not have an additional cytotoxic potential.

After a median follow-up of 50 months (range 2 to 158 months) from diagnosis, 63 patients (6%) developed secondary malignancies.

Univariate analysis revealed statistically significant differences for gender (P =.035) and age (P =.0001). The differences for gender and age remained statistically significant in multivariate analysis (gender: HR 1.7 [CI 95%, 1.037-2.818] P =.035; age: HR 4.190 [CI 95%, 2.308-7.607] P =.0001).

The researchers found treatments comprising HU and ALK did not appear to impact development of secondary malignancies in patients with ET in a 30-year period. Rate of secondary malignancies in untreated patients was similar to that of the treated patients; however, a statistically significant difference was seen in male patients and those older than 60 years.

Reference

1. Santoro C, Sperduti I, Lotagliata R, et al. Role of treatment on the development of secondary malignancies in patients with essential thrombocythemia [published online May 23, 2017]. Cancer Med. doi: 10.1002/cam4.1081