However, the low expression level of RECK was not associated with poor disease-free survival, except in BMSCC patients with age ≦40 years, advanced pathological stage and lymph node metastasis.
In addition, RECK mRNA levels were decreased in ESCC patients with hypermethylation of the RECK gene (∆MI >0.16; mean<sub>-∆∆Cq</sub>=-2.85) compared with those with hypomethylation of the RECK gene (∆MI ≤0.16; mean<sub>-∆∆Ct</sub>=-0.83), and there was a significant difference in the mRNA expression levels of RECK between those with N<sub>0-1</sub> and N<sub>2-3</sub> lymph node metastasis (P<0.0001).
RECK methylation status was significantly associated with clinical stage (P = 0.017), histological differentiation (P = 0.046), and lymph node metastasis (P = 0.003), but was not associated with gender, age, and tumor location (all P > 0.05).
In 263 betel quid chewing oral cancer patients, RECKrs10814325 polymorphism have a 2.26-fold (95% CI, 1.19-4.29) risk to have neck lymph node metastasis compared with RECK wild-type carrier.
Collectively, our results suggest that downregulation of the metastasis suppressor RECK is caused by promoter methylation in non-small cell lung cancer and is associated with K-ras mutation and lymph node metastasis.