autologous blood and marrow transplantation - Blog Science ...

24 Chapter 1: AML
exhibit low-density CD45 expression and low side-scatter characteristics, a series
of four gates were used to generate events considered to be true progenitor/stem
cells. Cells within the final progenitor/stem cell gate can be distinguished from
lymphocytes, monocytes, granulocytes, and other events that can contaminate the
CD34 +
population.
Preparative regimens
Thirty-five patients were treated with the following preparative regimen: Cy (60
mg/kg intravenously for 2 days, days -5 to -3) and fractionated total body
irradiation (TBI) (200 cGy twice daily for 3 days, total dose of 1200 cGy, dose rate
5 to 10 cGy/min, days -2 to 0). In 1988, the preparative regimen was changed
from Cy/TBI to busulfan (BU)/Cy2. Ninety-three patients were treated with BU (4
mg/kg/d orally for days -8 to -5) and Cy (60 mg/kg/d intravenously for 2 days,
days -4 and -3). One patient in CR2 was treated with BU (4 mg/kg/d orally for
4 days, days -9 to -6) and Cy (50 mg/kg/d intravenously for 4 days, days -5 to
-2). Ten patients (Stanford) were conditioned with BU (4 mg/kg/d orally, days -7
to -4) and VP-16 (60 mg/kg, day -3).
Statistical methods
Two patient sets were included in this analysis: the first was the total set of 138
patients and the second was the set of 55 patients who underwent autoBMT in
CR2/3 and received BU/Cy as their conditioning regimen. For both analyses, the
last transplant represented was performed on 10 February 1997 and the last followup
contact was 25 September 1997.
We estimated rates of relapse, overall survival (OS), and disease-free survival
after autoBMT (and 95% confidence intervals [CIs]) using the product-limit or
Kaplan-Meier method. 27
In addition, proportional hazards regression (Cox regression, relative risk
regression) was used to investigate the association of factors of interest with OS
and DFS in these patients. 28
The factors listed in Table 2 were allowed to enter the
05 and DFS models in a forward stepwise fashion (i.e., factors were evaluated first
individually to see whether they contributed substantially to predicting outcome).
The most significant univariate factor was then forced into the model, other factors
being allowed to enter if they contributed significantly given the presence of the
first. Additional factors were allowed to enter the models with interactions as
appropriate.
Some factors were transformed before analysis using logarithms to make their
distributions more symmetric. Body mass index was calculated as weight
(kg)/height (m) 2
.