[1408] Primary Myelofibrosis with del(20q): Association with JAK2V617F Status

Surabhi Kaul, Gary Lu, Jose M Gonzalez-Berjon, Srdan Verstovsek, Sherry A Pierce, Tariq Muzzafar. Universitiy of Texas MD Anderson Cancer Center, Houston, TX

Background: del(20q) is present in 22%-36% of patients with BCR-ABL1 negative myeloproliferative neoplasms (MPN). JAK2V617F mutation is present in polycythemia vera (PV) [90%], essential thrombocythemia (ET) [60%] and primary myelofibrosis (PM) [50%]. However, the role of this mutation in the pathogenesis of these distinct MPNs is not clear, since it is absent in a substantial percentage of patients. The aim of this study is to explore the correlation of del(20q) with JAK2V617F and the prognostic impact of del(20q) in MPNs with myelofibrosis.
Design: We identified 45 cases of MPNs with myelofibrosis and del(20q) in our institutional files from 12/2005 to 12/2011. Clinical, laboratory including cytogenetic and molecular, and survival data was collected. A set of 347 cases of PM with diploid karyotype from the institutional database was used as a control group.
Results: The 45 cases included 23 cases of PM, 16 cases of post-PV myelofibrosis (PV-MF), 6 cases of post-ET myelofibrosis (ET-MF); out of these JAK2V617F studies were available in 41 of the 45 cases. JAK2V617F was present in 17/20 (85%) of PM, 15/15 (100%) of PV-MF and 4/6 (67%) of ET-MF. JAK2V617F was present more frequently in cases of PM with del(20q) as compared with PM with diploid karyotype (p <0.05). There was no difference in survival between cases with PM and PV-MF. There was no difference in survival in PM cases with isolated del(20q) as compared to PM cases with diploid karyotype. Survival was shorter in both the PM and PV-MF cases with chromosomal abnormalities in addition to del(20q).
Conclusions: JAK2V617F is more common in cases of PM with del(20q) as compared to cases with diploid karyotype. Isolated del(20q) does not confer an adverse prognosis in PM; however additional karyotypic abnormalities are predictive of worse prognosis in both PM and PV-MF.
Category: Hematopathology

Wednesday, March 6, 2013 9:30 AM

Poster Session V # 214, Wednesday Morning

 

Close Window