POLYMORPHISM OF THE COX-2 GENE AND SUSCEPTIBILITY TO COLON AND RECTAL CANCER.

BACKGROUND: The colorectal neoplasm is the fourth most common malignancy among males and the third among females. In the Western world is estimated that 5% of the population will develop it, making this disease a major public health problem. AIM: To analyze the prevalence of the polymorphism -765G / C region of the COX-2 gene in colorectal cancer patients compared to a control group, analyzing the possible association between this polymorphism and susceptibility to colorectal cancer. METHOD: This is a case-control study with 85 participants. Were selected 25 with colorectal cancer (case group) and 60 participants without colorectal neoplasia (control group). The molecular genetic analysis was perform to identify the polymorphism -765G / C COX2 gene with standard literature technique. In addition, patient's clinical and pathological data were analyzed. RESULTS: There was a light increase in prevalence between men in the case group, although this difference was not statistically significant. The results showed a high prevalence of GC and CC genotype in individuals with colorectal cancer, demonstrating an association between the presence of the polymorphism in the COX2 gene and susceptibility to colorectal cancer in this pattern (p=0.02). Similarly, there was also difference in allele frequencies in the groups. When patients with cancer were separated by tumor location, there was a higher prevalence of polymorphism in the left colon (p=0.02). CONCLUSION: The polymorphism in the COX2 gene is associated with increased susceptibility to colorectal cancer, specially rectosigmoid tumors.

Polymorphism of the cox-2 gene and susceptibility to colon and rectal cancer / Polimorfismo do gene cox-2 e a suscetibilidade ao câncer de cólon e reto

ABSTRACT Background: The colorectal neoplasm is the fourth most common malignancy among males and the third among females. In the Western world is estimated that 5% of the population will develop it, making this disease a major public health problem. Aim: To analyze the prevalence of the polymorphism -765G / C region of the COX-2 gene in colorectal cancer patients compared to a control group, analyzing the possible association between this polymorphism and susceptibility to colorectal cancer. Method: This is a case-control study with 85 participants. Were selected 25 with colorectal cancer (case group) and 60 participants without colorectal neoplasia (control group). The molecular genetic analysis was perform to identify the polymorphism -765G / C COX2 gene with standard literature technique. In addition, patient's clinical and pathological data were analyzed. Results: There was a light increase in prevalence between men in the case group, although this difference was not statistically significant. The results showed a high prevalence of GC and CC genotype in individuals with colorectal cancer, demonstrating an association between the presence of the polymorphism in the COX2 gene and susceptibility to colorectal cancer in this pattern (p=0.02). Similarly, there was also difference in allele frequencies in the groups. When patients with cancer were separated by tumor location, there was a higher prevalence of polymorphism in the left colon (p=0.02). Conclusion: The polymorphism in the COX2 gene is associated with increased susceptibility to colorectal cancer, specially rectosigmoid tumors.

RESUMO Racional: A neoplasia colorretal representa a quarta malignidade mais comum entre homens e a terceira entre as mulheres. No mundo ocidental estima-se que 5% da população a desenvolverá, tornando-a grave problema de saúde pública. Objetivo: Analisar a prevalência de polimorfismo na região -765G/C do gene COX-2 em pacientes com câncer colorretal em relação a um grupo controle, analisando a possível associação entre este polimorfismo e a suscetibilidade a ele. Método: Foram incluídos neste estudo caso-controle 85 participantes. Selecionou-se 25 com neoplasia colorretal (grupo caso) e 60 pacientes sem neoplasia colorretal (grupo controle). Realizou-se análise genético-molecular para identificação do polimorfismo -765G/C do gene COX2 com técnica padrão da literatura. Além disso, foram levantados dados clínicos e anatomopatológicos dos pacientes. Resultado: Constatou-se discreto aumento de prevalência entre os homens no grupo caso, embora esta diferença não fosse estatisticamente significante. Os resultados revelaram alta prevalência do genótipo GC e CC nos indivíduos com câncer colorretal, demonstrando associação entre a presença do polimorfismo no gene COX2 e a suscetibilidade ao câncer colorretal nesta amostra (p=0,02). Similarmente, também se observou diferença nas frequências alélicas em relação aos grupos. Quando os pacientes com a neoplasia foram separados por localização do tumor, verificou-se maior prevalência do polimorfismo em pacientes de cólon esquerdo (p=0,02). Conclusão: O polimorfismo no gene COX2 está associado com a maior suscetibilidade ao câncer colorretal, especialmente em tumores do retossigmoide.