by Scott Baltic

Last Updated: 2008-08-26 15:44:45 -0400 (Reuters Health)

NEW YORK (Reuters Health) – A cytoprotective adjuvant used in cancer chemotherapy, amifostine, reduces the likelihood of ototoxicity in children undergoing cisplatin therapy for medulloblastoma, according to a study by U.S. and Australian researchers reported in the August 1 issue of the Journal of Clinical Oncology.

The authors note that although amifostine is known to help protect hematologic, renal, neural, and mucosal tissues during radiation or chemotherapy, without weakening the antitumor effects of these treatments, studies since the 1990s of its effects on cisplatin-induced hearing loss have given conflicting results.

For the current study, by Dr. Maryam Fouladi of St. Jude Children’s Research Hospital in Memphis, Tennessee, and colleagues recruited patients age 3 to 21 years with newly diagnosed and previously untreated average-risk medulloblastoma. Sixty-two patients who received amifostine were compared with a control group of 35 patients who did not receive the drug.

In addition to surgery that attempted maximal resection of the tumor, patients received radiation therapy. After a 6-week rest, they began four cycles of high-dose chemotherapy comprising cyclophosphamide, cisplatin and vincristine.

Because of its very short half-life, amifostine was given as an intravenous bolus infusion over a 1-minute period immediately before and again 3 hours into the cisplatin infusion.

All patients underwent serial hearing evaluations. For each patient, the hearing exam performed closest to 1 year after enrollment in the study was chosen for analysis.

At that point, 9 (14.5%) patients who had received amifostine had grade 3 or 4 ototoxicity, which requires the use of hearing aids, versus 13 (37.1%) in the control group (p = 0.005).

A 2-year follow-up found the incidence of severe hearing loss in the control group remained significantly greater at 35% versus 17% in the amifostine group (p = 0.048).

Adverse effects possibly attributable to amifostine included nausea or vomiting, hypotension, and hypocalcemia. The adoption of a prophylactic calcium chloride infusion minimized the latter problem.

J Clin Oncol 2008;26:3749-3755.

Copyright Reuters 2008.

[Source: Reuters]