The RASSF1A gene promoter was highly methylated in cancer tissues, and there were significant differences between normal esophagus tissues and esophageal squamous carcinoma (P < 0.05).
The expression of all three TSGs were significantly different between NSCLC subtypes: RASSF1A and FUS1 expression levels were significantly lower in squamous cell carcinoma (SCC), and NPRL2/G21 in adenocarcinoma (AC).
RASSF1A promoter methylation was associated with tumor grade (grade 3-4 vs 1-2: OR 2.31, 95% CI 1.12-4.77, P = 0.023), lymph node metastasis (yes vs no: OR 2.97, 95% CI 1.60-5.52, P = 0.001), tumor histology (squamous cell carcinoma vs adenocarcinoma: OR 0.49, 95% CI 0.22-1.08, P = 0.076), and HPV infection (positive vs negative: OR 0.45, 95% CI 0.28-0.73, P = 0.001).