Correspondence
G-CSF Priming in Acute Myelogenous Leukemia
N Engl J Med 2003; 349:2071-2072November 20, 2003
- Article
To the Editor:
The study by Löwenberg et al. (Aug. 21 issue)1 suggests that the possible priming effect of the administration of granulocyte colony-stimulating factor (G-CSF) concurrently with remission-induction therapy may improve the outcome of some cases of newly diagnosed leukemia. However, the priming effect of G-CSF was not demonstrated in an intention-to-treat analysis, only in a subgroup analysis. In addition to the small benefit of this treatment, if it has any at all, its safety remains questionable. During an early postinduction phase, the G-CSF group had a significantly higher mortality rate (55 of 321 patients died) than the group that did not receive G-CSF (34 of 319 patients; P=0.02). Early deaths of high-risk patients might have led to the apparent improvement in survival among patients who had a complete remission. The increase in mortality might be explained by the possibility that G-CSF aggravates leukemia by stimulating blasts or the possibility that G-CSF is associated with unrecognized fatal toxicity. It would be informative if the authors could present the causes of early deaths.
1 ReferencesNaoko Murashige, M.D.
Masahiro Kami, M.D.
Yoichi Takaue, M.D.
National Cancer Center Hospital, Tokyo 104-0045, Japan
mkami@ncc.go. jp 1
Lowenberg B ,van Putten W ,Theobald M , et al. Effect of priming with granulocyte colony-stimulating factor on the outcome of chemotherapy for acute myeloid leukemia. N Engl J Med 2003;349:743-752
Full Text | Web of Science | Medline
Author/Editor Response
The statement by Murashige et al. that the priming effect of G-CSF was not demonstrated in all patients but only in a subgroup and that it was not shown by an intention-to-treat approach is wrong. We reported that the benefit of G-CSF priming with respect to disease-free survival and the risk of relapse was apparent in the whole study population, according to an intention-to-treat analysis. We understand and agree that the causes of early death could be a reason for some concern. The causes of death are listed in Table 4 of the article. In our view, their diversity does not suggest an induction of cytokine release by G-CSF or any other common underlying problem related to the priming.
Bob Löwenberg, M.D.
Erasmus University Medical Center, 3000 CA Rotterdam, the Netherlands
b.lowenberg@erasmusmc. nl
