Characteristics and risk factors of cisplatin-induced ototoxicity in testicular cancer patients detected by distortion product otoacoustic emission.

ABSTRACT

OBJECTIVE: The characteristics and risk factors of the long-term ototoxic effect of cisplatin in testicular cancer patients was studied by measuring distortion product otoacoustic emissions (DPOAEs), which is a highly sensitive, new method for detecting high-frequency hearing loss. METHODS: 223 patients with a median follow-up time of 4.27 years (range 0.5-20 years) and a median age of 37 years (range 18-55 years) were assessed by DPOAE. 100 mg/m2 cisplatin were administered per cycle, in EP, BEP, VeIP, VIP or VPB regimens. The control group consisted of 40 testicular cancer patients without chemotherapy (median age 35 years, range 16-54 years). A detailed medical history evaluated audiological risk factors and hearing complaints. DPOAE was measured in eight frequencies from 750 to 8,000 Hz. Paired t test and Mann-Whitney test were used for statistical evaluation. RESULTS: Symptomatic ototoxicity was observed in 20% of the patients. In patients receiving cisplatin, no amplitude changes were detected. Beyond this dose, hearing impairment proved to be dose dependent. Contrary to the literature, not only high frequencies were affected. In patients receiving >or=400 mg/m2, our method could detect significant hearing impairment at lower frequencies that are important for speech perception. At 400 mg/m2, significant amplitude change was detected at 3,000 Hz (p = 0.01); at 500-600 mg/m2, significant amplitude change was detected at 1,500, 2,000 and 3,000 Hz (p = 0.004, 0.0001 and 0.0002, respectively), and at 700 mg/m2 significant amplitude change was detected at 3,000 Hz (p = 0.01). We detected the lowest amplitudes in those 44 patients who had symptomatic ototoxicity. The only statistically significant risk factor was the cumulative dose of cisplatin; neither smoking nor noise exposure were independent risk factors.

CONCLUSION:

DPOAE is a fast, noninvasive and reliable method in detecting late ototoxicity in testicular cancer patients. Contrary to the literature, not only high frequencies are affected. In patients receiving at least 400 mg/m2, using DPOAE we were able to detect significant hearing impairment at lower frequencies that are important for speech perception.