Hearing loss from chemotherapy underestimated

5 September 2006

Scientists at Oregon Health & Science University, USA, have found that the frequency and severity of ototoxicity - a condition in which platinum-based chemotherapy drugs damage hair cells in the inner ear - have long been underreported by the medical community.

The research, published in the current edition of the Journal of Clinical Oncology, found that a well-known classification system doctors use for reporting toxicities in patients, the National Cancer Institute's Common Terminology Criteria for Adverse Events, or CTCAE, doesn't consider high-frequency hearing loss, allowing the magnitude of ototoxicity in children to be miscalculated.

The purpose of the study is "to make people aware that this is more common than people think and we need to follow this issue," said Kristy Gilmer Knight, a pediatric audiologist at OHSU's Doernbecher Children's Hospital and the study's lead author.

Knight said a major problem for doctors trying to diagnose hearing loss from ototoxicity is that it's not that obvious. "The way it manifests itself is not that children lose all their hearing," she said. "The way it manifests itself is tricky. The typical presentation is high-frequency hearing loss, and so it may not look like they're having a problem, especially when communicating one-on-one in a quiet room. And kids won't complain about not understanding what was said when they're really little."

Scientists want to boost awareness of ototoxicity because it may soon be preventable.

Nancy Doolittle, associate professor of neurology, OHSU School of Medicine, and a researcher in the Blood Brain Barrier Program, which studies methods for breaching the brain's natural defense system to deliver chemotherapy compounds to tumors, has shown that sodium thiosulfate (STS) decreased hearing loss in patients with malignant brain tumors who were treated with carboplatin chemotherapy, which is given with the blood-brain barrier disruption technique. When STS was given four hours after carboplatin, ototoxicity decreased from 84 percent of patients to 29 percent.

Source: Oregon Health & Science University press release
(this link will open in a new window)

Deafness Research UK cannot be held responsible for the accuracy of the information contained in external websites.