Expression of c-mpl mRNA, the receptor for thrombopoietin, in acute myeloid leukemia blasts identifies a group of patients with poor response to intensive chemotherapy

Purpose: c-mpl, the human homolog of v-mpl, is the receptor for thrombopoietin. Given that c-mpl expression carries an adverse prognosis in myelodysplastic syndrome and given the prognostic significance of expression of other growth factor receptors in other diseases, we attempted to determine whether c-mpl mRNA expression is a prognostic factor in acute myeloid leukemia (AML). Patients and Methods: We analyzed bone marrow samples from 45 newly diagnosed AML patients by reverse-transcription polymerase chain reaction. Results: Samples from 27 patients (60%) expressed c-mpl mRNA (c-mpl(+)); their clinical and laboratory features were compared with those of the 18 patients without detectable levels of c-mpl (c-mpl(-)). No significant differences in age, sex, leukocyte count, French-American-British subtype, or karyotype group were found. c-mpl(+) patients more commonly find secondary AML (41% v 11%; P = .046) and more commonly expressed CD34 (67% v 12%; P = .0004). There was no significant difference in complete remission (CR) rate. However, c-mpl(+) patients had shorter CR durations (P = .008; median, 6.0 v > 17.0 months). This was true when only de novo AML patients were considered and when controlling for age, cytogenetics, or CD34 expression. There was a trend toward shorter survival in c-mpl(+) patients (P = .058; median, 7.8 v 9.0 months). Conclusion: These data suggest that c-mpl expression is an adverse prognostic factor for treatment outcome in adult AML that must be considered in the analysis of clinical studies using thrombopoietin in AML. (C) 1997 by American Society of Clinical Oncology.