Poor hematopoietic stem cell mobilizers: A single institution study of incidence and risk factors in patients with recurrent or relapsed lymphoma

The purpose of this retrospective study was to determine the incidence and predictive factors if any, of mobilization failure in lymphoma patients referred for autologous stem cell transplantation. A total of 588 lymphoma patients were referred for transplant consultation from January 2003 to December 2004. Predictors of mobilization failure were evaluated using logistic regression analysis including diagnosis, mobilization regimen, age, sex, type and number of prior chemotherapies, bone marrow cellularity, platelet count, white count, prior bone marrow involvement with malignancy, and prior radiation therapy. Two hundred and six patients were eligible for transplantation and underwent stem cell mobilization. Twenty-nine (14%) patients failed to mobilize adequate stem cells after the first attempt. For the entire group age (≥60 versus <60 years), diagnosis (Hodgkin's versus non-Hodgkin's lymphoma), use of cytokines alone, platelet count <150 × 10⁹/L, and bone marrow cellularity <30% were significant predictors for mobilization failure on univariate analysis. In view of small number of patients multivariate analysis was not possible. However, a low platelet count (150 × 10⁹/L) was the only significant predictor when the analysis was restricted to non-Hodgkin's lymphoma patients who were mobilized with chemotherapy. Mobilization failure rates are higher in patients with non-Hodgkin's lymphoma compared with those with Hodgkin's lymphoma. In the subset of patients who undergo chemomobilization for non-Hodgkin's lymphoma platelet count at the time of mobilization is a predictor of mobilization failure.