Expression and significance of Bcl-2 and P16 protein in esophageal squamous cell carcinoma and precancerous lesions

Objective To investigate the expression and significance of Bcl-2 and P16 protein in esophageal squamous cell carcinoma(ESCC) and precancerous lesions and the correlation with clinical pathologic parameters.Methods Immunohistochemistry assay(Envision method) was employed to examine the expression of Bcl-2 and P16 protein in ESCC tissues,intraepithelial neoplasia and normal esophageal mucosa.Results The Bcl-2 protein expression differed statistically(P0.01) among normal esophageal mucosa(1.4%),high-grade intraepithelial neoplasia(43.5%) and ESCC tissues(66.2%).The expression of Bcl-2 correlated with the differentiation of carcinoma and lymph node metastasis(P0.05).Compared with normal esophageal mucosa(40.4%),the level of P16 protein expression was appreciably lower(both P0.01) in high-grade intraepithelial neoplasia(20.3%) and ESCC tissues(20.3%).There was no remarkable difference in P16 protein expression between ESCC and precancerous lesion group(P0.05).Conclusion Bcl-2 and P16 play distinct roles at different developmental stages of ESCC.The loss of P16 takes place in early stage ESCC while Bcl-2 is associated with the development and progression of ESCC.Assay of Bcl-2 and P16 expression may serve as a reference for early diagnosis and prognosis of ESCC.