TITLE:
Immunohistochemical Expression of Ki-67, PCNA, pRb, p16, p53, Bcl-2 and Bax in Esophageal Adenocarcinoma and Barrett’s Associated Dysplasia
AUTHORS:
Andrey Iskrenov Kotzev, Margarita Angelova Kamenova, Alexander Petrov Tcherveniakov
KEYWORDS:
Esophageal Adenocarcinoma; Biomarkers; Cell Cycle; Proliferation; Apoptosis
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.3 No.6,
December
14,
2012
ABSTRACT: Background: Esophageal adenocarcinoma (EAC) has an extremely poor prognosis. There is a need to characterize the molecular alterations in the carcinogenesis of EAC in order to improve the diagnosis and treatment. Materials and Methods: We used 7 markers to explore the changes in the cell cycle, proliferation and apoptosis in patients with EAC and Barrett’s esophagus (BE)-associated dysplasia. The protein expression of Ki-67, PCNA, pRb, p16, p53, Bcl-2 and Bax was evaluated by immunohistochemistry in archival tissue samples, collected from 15 patients with EAC and 5 patients with BE-associated dysplasia. We analyzed also lymph-node, omentum and liver metastases from the primary esophageal tumors. Results: Ki-67, PCNA, pRb, p16, p53, Bcl-2 and Bax expression was observed in 100%, 87%, 60%, 40%, 100%, 7% and 93% of tumor samples, and in 100%, 80%, 0%, 80%, 80%, 20% and 100% of dysplasia samples, respectively. Significant difference in the expression of the markers between EAC and BE-associated dysplasia was detected for pRb (p = 0.006). Ki-67 expression was associated with clinicopathological parameter T (p = 0.012; V = 0.585). Ninefold higher risk to develop EAC was established for the patient with strong p53 expression, than the lacking p53 patient. Patients with strong p53 expression survived 6.8 months longer than the patients with weak p53 expression and 8.6 months longer than the patients with moderate p53 expression. No correlation was found between the expression of the other markers and prognosis. Conclusion: The results suggest that Ki-67, PCNA, pRb, p16, p53 and Bax participate in the pathogenesis of EAC, whereas Bcl-2 does not play essential role in EAC and BE-associated dysplasia. The balance between cell proliferation and apoptosis is lost in EAC and BE-associated dysplasia. Abnormal p53 protein expression has predictive and prognostic value in EAC. Larger prospective studies are needed to confirm these findings.