The Effect Of Prior Chemotherapy Courses With MD-AraC On The Hematopoietic Stem Cell Mobilization

To explore the number of courses of prior medium-dose cytarabine(MD-AraC) chemotherapy correlates with mobilization and transplantion efficiency.

90 consecutive patients with acute nonlymphocytic leukemia (ANLL) who underwent PBSC mobilization and apheresis in Haematology department of Nanfang hospital from August 1999 through November 2012 were analyzed. All patients with complete remission (CR) stages underwent leukapheresis after received granulocyte colony-stimulating factor (G-CSF) plus EA chemotherapy regimen for the mobilization, counted CD34 +cells by FACS. 85 patients finally has performed autologous hematopoietic stem cell transplantation (auto-HSCT), 1 performed allogeneic hematopoietic stem cell transplantation (allo-HSCT), 4 give up transplantation after mobilization. Patients were divided into two groups, MD-AraC 0-1 course in group A, MD-AraC 2 courses in group B, MD-AraC 3-5 courses in group C, then comparative analysis mobilization outcome, hematopoietic engraftment, relapse and survival of two groups. According to the acquisition of CD34 + cells number ≥ 2.0 x 10 ⁶ / kg, < 2.0 x 10 ⁶ / kg at most 3 leukapheresis by one mobilization, divided patients into success mobilizer group, the failure mobilizer group, then compared two groups of prechemotherapy and mobilization loads.

The mobilization outcome of 87 patients who could be evaluated, members in group A,B,C collected CD34 + cells (×10⁶ /Kg) was 4.67,2.65,2.33, A>B>C, comparative difference was statistically significant (P = 0.003). Overall 26 (29.9%) mobilizer cellected CD34 + cells < 2.0 x 10 ⁶ / kg and there are 7 (15.2%) patients ,10 (47.6%) patients, 9 (45.0%) patients respectively in A ,B, C, the group B and C failure mobilizer rates is significantly higher than group A (χ = 10.05, P = 0.007).while ,There patients were lowest blood volume, apheresis times, G-CSF doses in A group collected suffucuent CD34+ cell-dose, A<B<C. The success group patients’ MD-AraC courses(one course) with median was lower than the failure group patients’(two courses), the difference was statistically significant (P=0.012).While, the blood volume, apheresis times, G-CSF doses and days were lower in the success group (P<0.05). Engraftment after transplantation in A,B,C 3 groups were no difference. While, Megakaryocyte engraftment in success group were better than the failure group (P< 0.001).Of the 85 auto-HSCT patients, 23(27.6%) patients relapse, the incidence of relapse was not significantly different between the A, B and C groups or non-PM and PM groups( P>0.05). There was no difference in disease-free survival (DFS) and overall survival (OS) of A, B and C groups.

Patients who received more course chemotherapy with MD-AraC, acquired more difficulty of mobilization and lower incidence rate of good mobilization, and didn’t enhanced the post-transplantation DFS and OS. We conclude that prior chemotherapy is the most important potentially controllable variable for stem cell mobilization. In preparationfor Auto-HSCT, take into account the stem cell collection, patients should be minimize exposure to MD-AraC chemotherapy courses before mobilization.

No relevant conflicts of interest to declare.