Is hearing toxicity based upon cisplatin related to the genotypes of dna repair genes (ERCC1 ,ERCC2,XRCC1)

Objective: We aimed to investigate the relationship between hearing loss during cisplatin treatment and DNA repair genes, namely ERCC1, ERCC2 and XRCC1. Materials: For this purpose, 50 patients who were treated with cisplatinum were included in the study (29 females, 21 males; mean age 13.9±5.9). Diagnosis was CNS tumors in 16 patients whereas osteosarcoma in 13, germ-cell tumors in 7, neuroblastoma in 6, carcinoma in 5 and hepatoblastoma in 3. The healthy control group consisted of 29 females and 30 males with mean age of 13.4±3.7. The polymorphism in DNA repair genes was studied by using primer and probes in Light Cycler device after DNA isolation was carried out with PCR technique. Results: Among the patients, 22 had hearing loss documented in their charts. For ERCC1 gene, the patients with hearing loss had 50 % (11) of GG (wild type), 40 % (9) of AG (heterozygous), and 10 % (2) of AA genotypes (homozygous), while the patients without hearing loss had 28.6 % (8) of GG, 53,5 % (15) of AG, and 17.9 % (5) of AA genotypes. In control group, there were 49.2 % (29) of GG, 42.3 % (25) of AG, and 8.5 % (5) of AA genotypes. Among the patients, 22 had hearing loss documented in their charts. For ERCC2 gene, the patients with hearing loss had 18.2 % (4) of GG (wild type), 40.9 % (9) of TG (heterozygous), and 40.9 % (9) of TT genotypes (homozygous), while the patients without hearing loss had 10.7 % (3) of GG 39.3 % (11) of TG, and 50 % (14) of TT genotypes. In control group, there were 17 % (10) of GG, 44 % (26) of TG, and 39 % (23) of TT genotypes. Among the patients, 22 had hearing loss documented in their charts. For XRCC1 gene, the patients with hearing loss had 18.2 %(4) of CC (wild type), 59.1 %(13) of CT (heterozygous), and 22.7 % (5) of TT genotypes (homozygous), while the patients without hearing loss had 35.7 % (10) of CC, 50 % (14) of CT, and 14.3 % (4) of TT genotypes. In control group, there were 31 % (18) of CC, 54 % (32) of CT, and 15 % (9) of TT genotypes. No difference was found among the groups in the distribution of each 3 genes evaluated according to the result of Chi square test. Conclusion: In the light of these findings, a conclusion was reached as to the fact that there is no relationship between DNA repair genes and hearing toxicity of cisplatin.