Neurofibromatosis type-1 is a prognostic indicator in human gastric carcinoma

We investigated whether the Neurofibromatosis type-1(NF1) gene was of prognostic relevance to gastric cancer (GC) patients. Immunohistochemical staining of 160 matched GC tumor and adjacent normal tissue samples showed that 58.1% (93/160) of GC samples were NF1-positive as compared to 94.4% (151/160) of normal tissue samples (χ(2)=58.05, P <0.001). qRT-PCR analysis revealed that NF1 mRNA expression is lower in GC tissues than normal tissues (χ(2)=34.23, P <0.001). Moreover, NF1 protein and mRNA levels were associated with T stage (P <0.05) and TNM (P <0.001). No association was observed with other clinicopathological parameters, including gender, age, tumor size, lymph-node metastasis, cancer differentiation and distant metastasis (all P >0.05). Kaplan-Meier analysis revealed that negative or low NF1 were associated with poor overall survival (OS) in gastric cancer patients (P<0.001). Further univariate and multivariate cox regression analysis also showed that NF1 expression was an independent risk factor of survival of GC patients. These data show that NF1 has prognostic relevance to clinical outcomes in gastric cancer patients.