autologous blood and marrow transplantation - Blog Science ...

318 Chapter 6: Breast Cancer
progressive slowing of platelet recovery (P=0.0259), with median times to platelet
recovery from 25 to 30 days. Indeed, a more important observation, which we
believe is of substantial clinical importance, is the increased incidence of delayed
platelet engraftment beyond 30 days in this group (Fig. 4).
Isolex 300i CD34-selection procedure
To date, 14 patients entered on this study have undergone at least one high-dose
cycle. Eight patients have had their PB PCs undergo CD34-selection, with 19 cycles
completed to date. The results of the CD34-selection process are summarized in Table
5. Of the 19 cycles completed, the median time to ANC >0.5 and 1 .OX 10 9
/L is 10 (range
9-19) and 11 days (range 9-20), respectively. Time to platelets >20,50, and 100X10 9
/L
is 14 (range 12-25), 20 (range 14-22), and 26 days (range 19-45), respectively.
To analyze hematopoietic recovery, these 19 cycles from eight patients were
compared to 29 cycles from 11 other patients who received the same high-dose
regimen (six patients enrolled in the concurrent study whose PBPCs had not
undergone CD34-selection and five patients from the phase I study who received
the same drug dosages). In the cohort who had their PBPCs undergo CD34selection,
there was a moderate delay in recovery to ANC >0.5X 10 9
/L (/>=0.0387)
and platelets >20X10 9
/L (P= 0.0305) and >50X10 9
/L (/ >
=0.0421). No significant
differences in platelet recovery to >100X 10 9
/L were observed (/*=0.25) (Fig. 5).
Responses to therapy
Thirty-three patients were évaluable for response (Table 6). The response rate
for these 33 patients was 88% (29), with 6% (two) having stable disease and 3%
(one) progressive disease. All 22 patients with évaluable chemotherapy-sensitive
disease before high-dose chemotherapy had a further response (17 CRs, five PRs).
Of the 14 patients who had disease resistant to conventional-dose chemotherapy
before high-dose therapy (four patients with nonevaluable disease), there was a
70% (seven of 10) response rate with two (20%) having stable disease and one
(10%) with progressive disease. At a median follow-up for all alive patients of 8
months (range 4-21), the median progression-free survival is 11.3 months and the
median survival has not been reached (Fig. 6).
DISCUSSION
Previous studies of repetitive or sequential high-dose therapy in MBC
A number of other investigators have explored repetitive or sequential highdose
therapy for breast cancer, and selected studies are summarized in Table 7. The