Polymorphisms in nucleotide excision DNA repair genes in cisplatin pharmacogenetics associated with radiotherapy in patients with head and neck squamous cell carcinoma

Author(s)

Leisa Lopes Aguiar

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Ciências Médicas
• Defense date: 2014-08-25

Examining board members

Carmen Silvia Passos Lima; Luiz Paulo Kowalski; Cláudia Vianna Maurer Morelli

• Advisor: Carmen Silvia Passos Lima

Abstract

Cisplatin (CDDP) associated with radiotherapy (RT) is used in treatment of patients with head and neck squamous cell carcinoma (HNSCC). It is well known that both response to treatment and side effects vary among individuals. A possible explanation for this may be the genetic variability in metabolism of CDDP. The aim of this study was to access if inherited ability to repair DNA damage, mediated by ERCC1, XPC, XPD and XPF enzymes change the therapeutic side effects and urinary concentration of CDDP in HNSCC patients. We evaluated prospectively, 90 consecutive HNSCC patients of UNICAMP¿s Hospital, who received CDDP associated RT as neoadjuvant, definitive or palliative treatment. Genotypes of XPC Lys939Gln, XPD10 Asp312Asn, XPD23 Lys751Gln, XPF T30028C and ERCC1 C118T polymorphisms were analyzed by polymerase chain reaction and restriction enzyme digestion of peripheral blood DNA. Treatment response was assessed by clinical examination and computed tomography of neck. Treatment side effects were ranked through questionnaire and laboratory tests. Renal and hearing toxicities were assessed using, respectively, estimated creatinine clearance and glomerular filtration 51Cr-EDTA and pure tone threshold audiometry, before and after treatment. Urinary doses of CDDP were performed by high performance liquid chromatography. Statistical significance of differences between groups was calculated by Fisher's exact probability test or chi-square, logistic regression and ANOVA. Carriers of Gln allele of XPC Lys939Gln polymorphism had a 0.11-fold (95% confidence interval [CI]: 0.03-0.40) decreased risk of ototoxicity. Patients with Asn allele and Asn/Asn genotype of XPD10 Asp312Asn polymorphism had a 0.38-fold (95% CI: 0.14-0.99) decreased risk of nausea, and had a 8.50 (95% CI: 1.02-70.70) and 12.29-fold (95% CI: 1.19-126.04) increased risks of complete response to treatment and ototoxicity, respectively. Carriers of CC genotype of XPF T30028C polymorphism had a 0.13 (95% CI: 0.02-0.74) e 0.06-fold (95% CI: 0.007-0.67) decreased risks of nausea and vomiting, respectively. And, patients with T allele of ERCC1 C118T polymorphism had a 0.33-fold (95% CI: 0.11-0.97) decreased risk of vomiting. We concluded that these genetic polymorphisms have important roles in complete response rate and in occurrence of side effects. We believe that this data may constitute preliminary basis of future personalized treatment of HNSCC patients (AU)

• FAPESP's process: 11/15089-1 - Polymorphisms in DNA Repair Genes in the Pharmacogenetics of Cisplatin Associated with Radiotherapy in Patients with Head and Neck Squamous Cell Carcinoma
• Grantee: Leisa Lopes Aguiar
• Support Opportunities: Scholarships in Brazil - Master