Results
A total of 316 children received transplant for HM during a 10-year
period in one of the 5 FPBCC centers. Race was reported as White, Black,
Asian and unknown in 238 (75.3%), 57 (18%), 9 (2.8%) and 12 (3.8%)
patients, respectively. Subsequent analyses were done only for patients
reported to the CIBMTR as W and B, given very small numbers in other
categories. Table 1 presents patient and transplant characteristics by
race. There were no differences between W and B group in gender (male:
59% W, 60% B); median age at transplant (9 years);,performance score
(≥90: 74% W, 79% B); comorbidity number (0-1: 78% W, 79% B); disease
status (CR1/CR2: 79% W, 75% B); median time from diagnosis to
transplant (14 months W, 11 months B); use of bone marrow (BM),
peripheral blood (PB), or umbilical cord blood (UCB) (57%, 17%, 26% W
and 50%, 23%, 27% B, respectively); donor-recipient gender match
(matched: 51% W, 50% B); donor-recipient CMV serology match (matched:
58% W, 63% B); use of myeloablative regimens (99% W, 95% B), and use
of serotherapy (47% W, 39% B). There was a significant difference in
the use of HLA-MMD (53% W, 71% B, p =0.01). While the proportion
of MMUD was identical (16% W, 16% B), there was an increased use MMRD
and MMCBD among B (13% W, 25% B and 19% W and 26% B), respectively.
When comparing HLA-MMD use to fully HLA-matched donors, B, compared to
W, had RR of 1.47 [95% CI 0.7-3] of receiving a mismatched
unrelated donor PB or BM, RR of 2.34 [95% CI 1.2-4.4] of receiving
HCT from a mismatched related donor, and a RR of 1.9 [95% CI
0.99-3.6] of receiving a mismatched cord blood donor HCT.
As shown in Figure 1 Overall survival by race, there is no difference in
survival between W and B children (log-rank p = 0.72). The
24-month overall survival was 61% [95% CI 55-68%] in W children
and 60% [95% CI 48-75] in B children. Overall Survival by
HLA-match indicated significantly better-2 year survival of W
HLA-matched than HLA-mismatched transplant recipients (72.2% [95%CI
64.2-80.2] vs 51.6% [95%CI 41.8-61.7], log-rank p< 0.01) (Figure 1A). However, there was no difference in
overall survival between HLA-matched and HLA-mismatched B HCT recipients
(log-rank p = 0.94) with 2-year survival of 60.2% [95% CI
35-85] vs 59.3% [95% CI 43.2-75.6] (Figure 2B). Of note, only 16
B children received an HLA-matched HCT over 10-year period in Florida.
Table 2 Transplant outcomes among White and Black Children shows that W
and B recipients of MMRD HCT had higher 2-year survival rates than
recipients of MMUD and MMCBD HCT; however, these differences were not
statistically significant. Despite higher frequency of HLA-MMD among B
children, there was no significant difference in the incidence of aGVHD
(48% W, 35% B, p =0.1), incidence of cGVHD (18.7% W, 28% B,p =0.1), and causes of death from recurrent disease and
transplant-related toxicity (16%, 22% W and 14%, 25% B, p=0.9,
respectively), as outlined in Table 2.