Objective: To study the expression of retinoic acid receptor-beta (RAR-beta) mRNA and p16, p53, Ki67 proteins in squamous-cell carcinoma of the esophagus and its precursor lesions in a high risk population.
Methods: A total of 397 tissue specimens were collected from individuals with normal mucosa (NM, n = 25), mild dysplasia (MiD, n = 69), moderate dysplasia (MoD, n = 106), severe dysplasia (SD, n = 51), carcinoma in situ (CIS, n = 78), and squamous-cell carcinoma (SC, n = 68). Expression of RAR-beta mRNA was detected by in situ hybridization, and that of p16, p53 and Ki67 proteins by immunohistochemistry.
Results: The frequencies of RAR-beta mRNA expression in NM, MiD, MoD, SD, CIS and SC were 96.0%, 89.9%, 67.9%, 68.6%, 62.8%, and 63.2%, respectively. The frequencies of p16 expression were 88.0%, 71.0%, 64.2%, 51.0%, 53.8% and 52.9%; those of p53 expression were 4.0%, 39.1%, 57.5%, 52.9%, 67.9% and 69.1%; those of Ki67 expression were 0, 40.6%, 61.3%, 58.8%, 59.0% and 75.0%, respectively.
Conclusion: There are no significant differences in four biomarkers expression between carcinoma of the esophagus and its precursor lesions.