Determination of accuracy of polycythemia vera diagnoses and use of the JAK2V617F test in the diagnostic scheme.

In 2005, three independent research groups described the presence of a specific mutation in the JAK2 gene, JAK2V617F, in patients with a Philadelphia chromosome-negative myeloproliferative neoplasm (MPN). The percentage of patients with the mutation varied according to specific disease with >98 % of polycythemia vera (PV) patients having the mutation. In 2008, the World Health Organization issued new diagnostic criteria for PV including use of the JAK2V617F test as a major diagnostic criterion. The goal of the present study is to determine the accuracy of diagnosing PV in a community practice and reporting of PV to cancer registries, as well as assessing the integration of molecular testing into diagnostic paradigms. Using Geisinger Medical Center's electronic medical records (EMR), patients with a PV diagnosis being seen by a hematologist/oncologist during 2004-2009 were identified. Records were reviewed by a single hematologist/oncologist to determine accuracy of the treating physician's diagnosis and use of the molecular test for the JAK2V617F mutation. There was a diagnosis of PV from the treating physicians in 121 of the 204 evaluable patients (59 %) and another MPN in 21 (10 %). However, we confirmed a PV diagnosis in only 90 patients (44 %). Of the 90 confirmed PV patients, 64 were JAK2V617F-mutation positive while 24 were not tested. While JAK2V617F testing has made a major impact in facilitating the successful delineation of the type of polycythemia (PV versus secondary polycythemia) in patients evaluated in a large, community-based Hematology/Oncology practice, physician usage of other critical tests is inconsistent leading to errors in diagnosis. JAK2V617F mutation testing in combination with other diagnostic criteria may help reduce diagnostic errors.