borderline significantP =0.051
Huang et al only analyzed whethe RASSF1A promoter methylation was linked to tumor stage (five studies with 252 cases) and grade (four studies with 190 cases), showing that RASSF1A promoter methylation had a borderline significant correlation with tumor stage ( P =0.051) and a significant association with tumor grade ( P =0.001). 49 Our meta-analysis involving more patients suggested that RASSF1A promoter methylation was significantly linked to tumor grade (13 studies with 686 patients with RCC, P <0.001) and clinical stage (8 studies with 463 patients with RCC, P =0.001).