Detection of late ototoxic side effect of cisplatin by distortion otoacoustic emission (DPOAE)

Cisplatin-based chemotherapy results in high cure rate in testicular cancer. The issue of toxicity is of special concern in young men with a probability of cure of at least 70-80% even in disseminated disease. As the literature shows, the ototoxic side effects of cisplatin have been studied mostly by conventional method. The authors used distortion product otoacoustic emission to detect the long-term ototoxic effect of cisplatin in 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). Cisplatin (20 mg/m(2) body surface) was administered for five days per cycle, in combination with other antitumor drugs. The control group consisted of 40 testicular cancer patients who did not receive chemotherapy, with a median age of 35 years (range 16-54 years). A detailed medical history based on a standardized questionnaire evaluated hearing complaints and audiological risk factors, such as head injuries, chronic otitis media, previous noise exposure and familial hearing loss. DPOAE was measured at 8 frequencies from 750 to 8000 Hz. No amplitude changes were detected in patients receiving =300 mg/m(2) cisplatin. At higher doses, contrary to the literature, not only high frequencies were affected: our method could detect significant hearing impairment at lower frequencies important for speech perception in patients receiving at least 400 mg/m(2) cisplatin. The lower frequencies where significant amplitude changes were detected were 3000 Hz at 400 mg/m(2), and 1500, 2000 and 3000 Hz at 500-600 mg/m(2). We detected the worst hearing in the case of patients who had symptomatic ototoxicity. Age and the cumulative dose of cisplatin proved statistically significant risk factors, while smoking or noise exposure did not have predictive value. As a conclusion, DPOAE is a fast, noninvasive and reliable method for the detection of late ototoxicity in testicular cancer patients. In our study hearing loss correlated with the cumulative dose of cisplatin. Hearing impairment contributes to the already compromised situation of cancer patients.