Pb1726: hearing status of survivors of childhood acute lymphoblastic leukemia

Topic: 2. Acute lymphoblastic leukemia - Clinical Background: Acute lymphoblastic leukemia (ALL) accounts for 75% of all childhood leukemias and 30% of all childhood cancers. Hearing loss (HL), a late effect of childhood cancer therapy, is mainly associated with ototoxic chemotherapeutics and cranial irradiation. In addition, using ototoxic drugs, like empirical antibiotics, including aminoglycosides, in patients experiencing febrile neutropenia adds to the ototoxicity risk. Aims: To assess the hearing status of children with ALL after they have completed treatment. Methods: Two groups of children were included; group I consisted of fifty-five survivors of ALL who have completed treatment for ALL at Alexandria University Children’s Hospital, and group II fifty-five healthy age and sex-matched children as controls. Children aged ≥ 4 and < 18 years were included after at least 3 months of completing chemotherapy for ALL. Children were excluded if they had a history of otologic disease, a family history of HL, or had received known ototoxic drugs before treatment for ALL. The audiological assessment consisted of middle ear pressure and mobility of the tympano-ossicular chain immittancemetry. Conventional pure-tone audiometry was done in a soundproof booth utilizing interacoustics AD 229 and HDA 39 - Sennheiser headphones. Hearing thresholds were measured using air conduction at frequencies ranging from 250-8000 Hz and bone conduction at frequencies ranging from 250-4000 Hz. A speech audiometry test is done using bi-syllabic words to test the speech-recognition threshold, while a speech-discrimination score was obtained using a monosyllabic word test. Results: The patients’ age ranged from 5 to 17.5 years, and the median was 9 years; there were 34 (61.8%) boys. The median time between the end of therapy and the examination date was 1.64 years (0.33 – 6.87 years). In the control group, all children showed normal audiogram results, whereas, in the patients’ group, only 89% (98 ears) were normal, bilateral conductive HL was present in 5 (10 ears) patients, and one patient had sensorineural HL. There was no statistically significant difference between the word discrimination test between patients and the control group. In contrast, the mean pure tone average was significantly higher in patients compared to controls, p= 0.029. Significantly more patients had a type A tympanogram (normal) in the control group (97.3%) compared to patients (82.7%), p <0.001. There was a statistically significant relation between abnormal audiogram results and the frequency of otitis media, p=0.035. Similarly, a history of drum perforation affected the pure tone average, p= 0.02. Summary/Conclusion: HL is not uncommon in patients treated for ALL, the most common type being conductive HL. The pure tone average and the middle ear pressure were significantly affected in the patients compared to the control group, especially in relation to recurrent otitis media and drum perforation. Keywords: Long-term follow-up, Late complications and outcome, Acute lymphoblastic leukemia