Early testing
Around three-quarters of children up to the age of five experience hearing damage; in older children this is almost half. The hearing loss usually develops at the start of treatment with platinum chemotherapy. Annelot Meijer: 'It was not always clear how, how often and when hearing should be examined during cancer treatment, especially in young children. Therefore, together with an international group, we made recommendations for testing hearing loss for different ages from 0 to 18 years. In this way, we can spot problems with hearing early and we can offer appropriate advice and treatment to improve hearing. Hearing loss can hinder children in their communication skills, school performance and social-emotional development. That's what we try to minimize as much as possible through timely testing.'
Genetic predisposition
An international study examined 368 children with cancer with 2052 hearing tests. The severity of hearing loss is influenced by several factors, the researchers discovered. They found that age and tumor type play a role, as well as the intensity of cisplatin treatment and combination therapy with other drugs, such as antibiotics, during cancer treatment. Genetic predisposition can also play a role in the development of hearing loss, the scientists found. They identified a new genetic variant in the TCERG1L gene linked with a higher risk of hearing loss in children treated with cisplatin. Annelot Meijer: 'It is important that the influence of this genetic variant is confirmed on a large scale in the future. Then we can eventually develop risk scores to identify patients who are at high risk of developing different types of inner ear problems such as hearing loss, tinnitus and vertigo. We saw that tinnitus is three times more common in childhood cancer survivors compared to their siblings. And also that treatment with cisplatin, radiation to the head and brain surgery increase this risk. Introducing screening for hearing loss and tinnitus during and after cancer treatment is therefore of great importance.'