Radioinjúria Associada aos Polimorfismos de Base Única dos Genes ATM E TP53 em Pacientes com Câncer de Cabeça e Pescoço

Abstract

The head and neck cancer is the fifth most common in Brazil, being the most predominant histology type the squamous cell carcinoma. Radiation therapy is a procedure for treatment with the efficacy variable, and may play an important role in controlling tumor growth. Faced with this therapy, the patient is exposed to ionizing radiation that can cause adverse effects resulting cessation of treatment. The objective was to evaluate the association of polymorphisms of TP53 and ATM genes in patients with head and neck cancer with adverse effects on normal tissues presented as a result of radiotherapy. Materials: The DNA was extracted 54 samples of peripheral blood of patients with head and neck cancer, then the fragments of TP53 and ATM were amplified and subsequently sequenced to check for any polymorphism which may be responsible for the radiosensitivity of patients. Statistical analysis was performed using the SPSS 17.0 software. Results and Discussion: In univariate analysis, patients who had experienced adverse effects RT suspended acute low and high grade with RTOG skin (p = 0.012). Those who had a family history of cancer showed higher adverse acute laryngeal RTOG TGI high (p = 0.040). The exchange C> T at position 11322 of TP53 (intron 3), the ATM and TP53 polymorphisms analyzed and the frequency of acute and chronic adverse effects were not significant (p>05). Conclusions: Based on these results is of utmost importance that alternatives are created to predict the dose to be prescribed during radiotherapy, preventing adverse effects and discontinuation of treatment and also providing better tumor control.