High Expression Of Monoamine Oxidase A Is Associated With The Poor Prognosis Of Gastric Cancer

Aim: Gastric cancer(GC)is the second most prevalent malignancy among men in China according to a recent report from National Central Cancer Registry of China.Although the declining trends in mortality were observed in this report,gastric cancer is still the third cause of cancer-related death among both men and women.Most patients are diagnosed with GC at late-stages which results in the poor prognosis.The five-year overall survival for patients at stage IV is less than 30%.TNM category is the best clinical prognostic factor for GC,but the significant differences in prognosis can also be observed for patients at the same stage.Thus,it's important to find out the other factors to predict prognosis more accurately.Monoamine oxidase A(MAOA)is originally identified as a neurotransmitter regulator.MAOA is located in the mitochondrial outer membrane and catalyzes the oxidative deamination of monoamine neurotransmitters and dietary amines.Recently,the role of MAOA expression in cancer progression gained much attention.Both oncogenic and anti-oncogenic effect were observed.Down-regulation of MAOA was associated with cholangiocarcinoma and esophageal squamous cell carcinoma risk.Up-regulation of MAOA was associated with lung cancer,renal cell carcinoma and prostate cancer risk.The decreased level of MAOA correlated with the size of pancreatic ductal adenocarcinoma and shorter patient survival time and the metastasis of hepatocellular carcinoma.The overexpressed MAOA can inhibit apoptosis of prostate cancer cells and promote the metastasis of prostate cancer.The main topic of this project is to explore the correlation between Monoamine oxidase A expression and gastric cancer overall survival.Methods: This study selected 190 gastric cancer specimens from January2006 to July 2007 in the First Affiliated Hospital of China Medical University.The data of clinical histopathological diagnosis and tumor classification were taken from the medical records of the patients.All the patients were primary gastric cancer,and they were not treated with chemotherapy before operation.All the patients received total gastric or gastric resection and regional lymph node dissection.Detection of monoamine oxidase A MAOA protein in 190 cases of gastric carcinoma and its corresponding expression,tumor tissues by immunohistochemical method at the same time,we also regression analysis,Cox regression,survival curve and Log-rank test,stratified analysis and other analytical methods of its relationship with clinicopathological parameters and prognosis of the depth of the data correlation analysis by single factor.Results: Monoamine oxidase A was upregulated in primary gastric cancer.The expression level of Monoamine oxidase A was associated with sex(P=0.004)and macroscopic type(P=0.002).The high expression of Monoamine oxidase A was significantly correlated with poorer gastric cancer prognosis(HR=1.613,95%CI 1.017-2.560,P=0.042).The multivariate analysis indicated the independent prognostic role of Monoamine oxidase A in gastric cancer overall survival.The prognostic role of Monoamine oxidase A in gastric cancer was observed in patients with some certain characteristics.Conclusions: The high expression of MAOA is independent prognostic predictor for poorer gastric cancer overall survival.This role may be played in patients without distant metastasis.