Is Methotrexate Ototoxic? Investigating the Ototoxic Late Effects of Pediatric Cancer Treatment

Purpose: Pediatric cancer survivors often experience long-term adverse health conditions or late effects, including hearing loss, that are attributable to cancer therapy. Ototoxic late effects have been documented in patients with cancer treated with cisplatin-based chemotherapy and/or radiation. This study evaluated the late effects of methotrexate as compared to cisplatin and other cancer therapy agents on pediatric cancer survivors at the Children's Hospital of New Orleans in Louisiana (CHNOLA) and patients currently undergoing cancer treatment at Our Lady of the Lake (OLOL) Hospital in Baton Rouge, Louisiana.

Method: A retrospective chart review was conducted of medical records from the CHNOLA Audiology Clinic and the Treatment After Cancer Late Effects clinic, which followed patients 2-19 years after cancer treatment completion and current patients with pediatric cancer at OLOL. This study identified pediatric cancer survivors between 2 and 24 years of age with treatment protocol information and audiological evaluations. Association studies were performed to calculate values using an exact chi-square test.

Results: More than 44% of late-effects patients had significant hearing loss; mild-to-profound hearing loss was observed in 37.5% of patients who received methotrexate treatment without cisplatin or irradiation. Eighty-three percent of the patients who received cisplatin had late-effect hearing loss. In patients currently receiving cancer treatment, 12% had significant hearing loss.

Conclusions: The results from this study suggest that children who receive therapies not clinically established as ototoxic (i.e., methotrexate) may still be at a high risk of developing long-term hearing loss as a late effect. Due to the high incidence rate of hearing loss among patients with pediatric cancer, we recommend that audiologists be part of the late-effects care team. This study also demonstrates that patients with pediatric cancer treated with methotrexate should receive routine long-term auditory monitoring as part of their standard of care to detect and manage hearing loss early, minimizing adverse outcomes.