The results of this study showed that the positive expression rates of SHOX2, RASSF1A and PTGER4 in cancer tissues of LC patients were significantly lower than that in paracancerous tissues, suggesting that low expression of SHOX2, RASSF1A and PTGER4 is common in LC patients. This evidence concerns the gene RASSF1 and laryngotracheoesophageal cleft.