AIM:To study the relationship between the expressionprofiles of a plant-associated human cancer antigen andcarcinogenesis of esophagus and its significance.METHODS:We analyzed expression of a plant-associatedhuman cancer antigen in biopsy specimens of normal (n=29),mildly hyperplastic (n=29),mildly (n=30),moderately (n=27)and severely dysplastic (n=29) and malignant esophageal(n=30) tissues by immunohistochemistry.RESULTS:The plant-associated human cancer antigenwas mainly confined to the cytoplasm and showed diffusetype of staining.Positive staining was absent or weak innormal (0/30) and mildly hyperplastic tissue samples (2/29),while strong staining was observed in severe dysplasia(23129) and carcinoma in situ (24/30).There wassignificant difference of its expression between normalmucosa and severely dysplastic tissues (P<0.001) orcarcinoma in situ (P<0.001).Significant difference wasalso observed between mild dysplasia and severe dysplasia(P<0.001) or carcinoma in situ (P<0.001).An overall trendtoward increased staining intensity with increasing gradeof dysplasia was found.There was a linear correlationbetween grade of lesions and staining intensity (r=0.794,P<0.001).Samples from esophageal cancer showed nohigher levels of expression than those in severely dysplasticlesions (P>0.05).CONCLUSION:The abnormal expression of this plant-associated human cancer antigen in esophageal lesions isa frequent and early finding in the normal-dysplasia-carcinoma sequence in esophageal carcinogenesis.It mightcontribute to the carcinogenesis of esophageal cancer.Theabnormal expression of this plant-associated human cancerantigen in esophageal lesion tissues may serve as apotential new biomarker for early identification ofesophageal cancer. AIM: To study the relationship between the expressionprofiles of a plant-associated human cancer antigen and carcinogenesis of esophagus and its significance. METHODS: We analyzed expression of a plant-associated human cancer antigen in biopsy specimens of normal (n = 29), mildly hyperplastic Mildly (n = 27) and severely dysplastic (n = 29) and malignant esophageal (n = 30) tissues by immunohistochemistry .RESULTS: The plant-associated human cancer antigen was mainly confined to the cytoplasm and showed diffusetype of staining. Positive staining was absent or weak innormal (0/30) and mildly hyperplastic tissue samples (2/29), while strong staining was observed in severe dysplasia (23129) and carcinoma in situ ). There was significant difference of its expression between normalmucosa and severely dysplastic tissues (P <0.001) orcarcinoma in situ (P <0.001) .Significant difference was observed between mild dysplasia and severe dysplasia (P <0.001) 0.001) .An Overall trendtoward increased staining intensity with increasing grade of dysplasia was found. Where was a linear correlation between grade of lesions and staining intensity (r = 0.794, P <0.001). Samples from esophageal cancer showed nohigher levels of expression than those in severely dysplastic lesions (P> 0.05) .CONCLUSION: The abnormal expression of this plant-associated human cancer antigen in esophageal lesions isa frequent and early finding in the normal-dysplasia-carcinoma sequence in esophageal carcinogenesis. It might Contribute to the carcinogenesis of esophageal cancer. -associated human cancerantigen in esophageal lesion tissues may serve as apotential new biomarker for early identification of esophageal cancer.