The impact of cytogenetic abnormalities on the prognosis of primary myelofibrosis: a prospective survey of 202 cases in Japan.

Cytogenetic abnormalities were often observed in primary myelofibrosis patients. The presence of specific cytogenetic abnormalities, such as sole abnormalities of chromosome 13q-, 20q-, or -7/7q-, is reported to have the influence on the prognosis of primary myelofibrosis. We analyzed the data from the prospective survey of Japanese primary myelofibrosis patients which was conducted from 1999 to clarify the impact of cytogenetic abnormalities on the prognosis of primary myelofibrosis. A total of 202 primary myelofibrosis patients had the cytogenetic and the prognostic data. Eighty (40%) out of 202 cases had cytogenetic abnormalities, and an association was evident for platelet counts. Although the presence of an abnormal karyotype did not affect the prognosis, primary myelofibrosis patients with cytogenetic abnormalities other than 13q- and 20q- showed an inferior prognosis compared to patients with a normal karyotype or sole 13q- or 20q- abnormalities. Patients with an unfavorable cytogenetic profile (abnormal cytogenetics other than 13q- or 20q-) also had a greater tendency to transform to leukemia than patients with a favorable cytogenetic profile (normal cytogenetics, sole abnormalities of either chromosome 13q-, or 20q-). Abnormal cytogenetics other than 13q- or 20q- in primary myelofibrosis patients has the poor prognostic effect for both survival and the risk of leukemic transformation.