1. Patient characteristics
Eighteen patients were enrolled with a median age at initiation of MC of
7.3 years (range, 2.7–16.1 years), and the sex ratio was 1:1. Seven
patients were diagnosed with brain tumors, including 2 cases of atypical
teratoid/rhabdoid tumor, 2 cases of ependymoma, and 1 case each of
medulloblastoma, mixed germ cell tumor, and infantile hemispheric
glioma. The remaining 11 tumors were 4 cases of neuroblastoma (NBL), 3
cases of rhabdomyosarcoma (RMS), and 1 case each of Ewing sarcoma,
malignant peripheral nerve sheath tumor (MPNST), desmoplastic small
round cell tumor, and extrarenal rhabdoid tumor.
The median time from diagnosis to MC initiation was 28 months (range,
14–84 months). The reasons for starting MC and disease status at that
time were as follows: 2 patients with RMS and MPNST achieved CR and
received MC as maintenance therapy; and 5 patients had PR to prior
therapies or maintained SD without relapse (4 patients from this group
received MC as consolidation therapy and the remaining patient with NBL
received MC as a bridging therapy to 131-iodine-metaiodobenzylguanidine
therapy). The remaining 11 patients received MC as palliative therapy
for tumors that showed PD to conventional chemotherapies.
The choice of treatment regimen was at the discretion of the attending
physician and was mainly set according to the newly published trials
data available at the time.4–10 Antiangiogenic
agents, including bevacizumab, celecoxib, and fenofibrate, were combined
when deemed appropriate. Two patients with RMS received a combination
therapy of oral cyclophosphamide and intravenous vinorelbine, which was
developed as maintenance therapy for primary RMS.17
Detailed characteristics of each patient are shown in Table 1. Of the 18
patients, 16 had received cyclophosphamide and 18 had received etoposide
with a cytotoxic dose before MC—indicating no impact to the treatment
outcomes of MC.