Tolerability of ifosfamide-containing regimen in patients with high-risk
renal and INI-1-deficient tumors
Abstract
Background: Outcomes for children with high-risk renal (HRR)
and INI-1-deficient (INI-) tumors are unacceptably poor. Concerns about
excessive toxicity – as many are infants and/or undergo nephrectomy –
have resulted in decreased chemotherapy dosing and omission of the
nephrotoxic drug ifosfamide in collaborative group studies. As cause of
death for children with these cancers remains overwhelmingly more from
progressive disease rather than treatment toxicity, we examined the
tolerability of an intensive ifosfamide-containing-regimen.
Procedure: Retrospective review of children with HRR/INI-
tumors treated at a single institution with vincristine, doxorubicin,
cyclophosphamide alternating with ifosfamide, carboplatin, etoposide
(VDC-ICE) from 2006-2016. The primary outcome was regimen tolerability
including kidney injury and grade 3-5 non-hematologic toxicities.
Results: Fourteen patients with a median age of 1.7 years
(range 0.1-10.5) treated with VDC-ICE were identified. Diagnosis
included malignant rhabdoid tumor (n=9) [primary renal (n=2)];
diffuse anaplastic Wilms tumor (n=3); clear cell sarcoma of the kidney
(n=1); and anaplastic chordoma (n=1). All children with primary renal
tumors (43%) underwent complete (n=5) or partial nephrectomy (n=1)
before chemotherapy. Nine (64%) completed all intended cycles of
chemotherapy; n=5 (36%) did not due to disease progression. Unplanned
hospitalizations occurred in 13 (93%) patients, most commonly for
febrile neutropenia. No patient experienced severe organ toxicity,
diminished renal function, treatment discontinuation due to toxicities,
or treatment-related death. Conclusions: In children with
HRR/INI- tumors, VDC-ICE chemotherapy was well-tolerated without
excessive toxicities, even amongst young patients with solitary kidneys.
Concerns about toxicity should not preclude an intensive
ifosfamide-containing regimen from use in future trials in this
population.