Education, tobacco smoking, alcohol consumption, and IL-2 and IL-6 gene polymorphisms in the survival of head and neck cancer

• Published in: Brazilian journal of medical and biological research 2011-10, Vol.44 (10), p.1006-1012
• Main Authors: López, R V M, Zago, M A, Eluf-Neto, J, Curado, M P, Daudt, A W, da Silva-Junior, W A, Zanette, D L, Levi, J E, de Carvalho, M B, Kowalski, L P, Abrahão, M, de Góis-Filho, J F, Boffetta, P, Wünsch-Filho, V
• Format: Article
• Language: English
• Subjects: Aged; Alcohol; Alcohol Drinking - adverse effects; BIOLOGY; Cancer prognosis; Carcinoma, Squamous Cell - etiology; Carcinoma, Squamous Cell - mortality; Cohort Studies; Disease-Free Survival; Educational Status; Female; Genotype; Head and neck cancer; Head and Neck Neoplasms - etiology; Head and Neck Neoplasms - mortality; Humans; Interleukin; Interleukin-2 - genetics; Interleukin-6 - genetics; Male; MEDICINE, RESEARCH & EXPERIMENTAL; Middle Aged; Polymorphism, Genetic - genetics; Prognosis; Risk Factors; Smoking; Smoking - adverse effects; Squamous Cell Carcinoma of Head and Neck; Survival analysis
• ISSN: 0100-879X; 1414-431X; 1414-431X; 0100-879X
• DOI: 10.1590/S0100-879X2011007500097

The association of education, tobacco smoking, alcohol consumption, and interleukin-2 (IL-2 +114 and -384) and -6 (IL-6 -174) DNA polymorphisms with head and neck squamous cell carcinoma (HNSCC) was investigated in a cohort study of 445 subjects. IL-2 and IL-6 genotypes were determined by real-time PCR. Cox regression was used to estimate hazard ratios (HR) and 95% confidence intervals (95%CI) of disease-specific survival according to anatomical sites of the head and neck. Mean age was 56 years and most patients were males (87.6%). Subjects with 5 or more years of schooling had better survival in larynx cancer. Smoking had no effect on HNSCC survival, but alcohol consumption had a statistically significant effect on larynx cancer. IL-2 gene +114 G/T (HR = 0.52; 95%CI = 0.15-1.81) and T/T (HR = 0.22; 95%CI = 0.02-3.19) genotypes were associated with better survival in hypopharynx cancer. IL-2 +114 G/T was a predictor of poor survival in oral cavity/oropharynx cancer and larynx cancer (HR = 1.32; 95%CI = 0.61-2.85). IL-2 -384 G/T was associated with better survival in oral cavity/oropharynx cancer (HR = 0.80; 95%CI = 0.45-1.42) and hypopharynx cancer (HR = 0.68; 95%CI = 0.21-2.20), but an inverse relationship was observed for larynx cancer. IL-6 -174 G/C was associated with better survival in hypopharynx cancer (HR = 0.68; 95%CI = 0.26-1.78) and larynx cancer (HR = 0.93; 95%CI = 0.42-2.07), and C/C reduced mortality in larynx cancer. In general, our results are similar to previous reports on the value of education, smoking, alcohol consumption, and IL-2 and IL-6 genetic polymorphisms for the prognosis of HNSCC, but the risks due to these variables are small and estimates imprecise.