Abstract

"The silencing of p16INK4alpha (p16) tumor suppressor gene by aberrant methylation has been described as a common event in human tumoral types, such as squamous cell lung carcinoma (SCLC). This is a very frequent histological type in Chile, usually associated to chronic smokers. The purpose of this study was to investigate the p16 methylation status in patients with SCLC. Using a MSP (methylation-specific PCR), we determined that 25 out of 29 (86%) of SCLC patients had hypermethylation of p16 gene. There was also a significant concordance between hypermethylation of p16 gene and the presence of SCLC (p = 0.00005). According to our results, smokers have a 202-fold higher risk to develop SCLC than no-smokers (odds ratio, 201,7; 95% confidence interval, 7.18-5593). Therefore, our results suggest that hypermethylation of p16 gene is an useful prognostic marker in chronic smokers candidates to develop SCLC and patient with clinic suspicion of SCLC"