Immunohistochemical Expression of P53 and Bcl-2 In Esophageal Tumors

Abstract

This is a descriptive retrospective hospital based study conducted in Khartoum state during the period from March to December 2014 aimed to detect the expression of P53 and Bcl-2 proteins in esophageal tumors using immunohistochemical method. Fifty paraffin embedded blocks previously ddiagnosed as esophageal tumors were collected from Soba university hospital. Samples include 40 (80%) malignant tumors, 34 (68%) from those 40 samples were squamous cell carcinoma and 6 (12%) were adenocarcinoma , and 10 samples (20%) were benign tumors. The study samples includes 32 (64%) males and 18 (36%) females. with mean of age was 60.7 years. Two sections were cut from each paraffin block by rotary microtome and stained by immunohistochemical method using modified new indirect method (Dako technique) for detection of P53 and Bcl-2. Data collected from patients files and results obtained and analyzed using statistical package of social science program (SPSS). The immunohistochemical expression of P53 was detected in 23 (46%) samples, all of them were malignant and negative in 27 (54%) samples, 17samples (34%) of them were malignant and the remaining 10 samples (20%) were benign, and there was statistical association between P53 expression and malignant tumors of the esophagus (P.value =0.001). Out of 23 positive samples, 19 (38%) samples were squamous cell carcinoma, and 4 (8%) samples were adenocarcinoma with no statistical association between the type of tumor and P53 expression (P.value = 0.622). The expression of p53 was compared with degree of histological differentiation and it has been detected in 11(22%) samples of moderately differentiated tumors, and 11(22%) samples of poorly differentiated tumors with statistical association with the grade of tumor (P.value =0.002). Immunohistochemical expression of Bcl2 was detected in 5 (10%) samples and negative in 45 (90%) samples, 35 (70%) of them were malignant and 10 (20%) were benign with no statistical association between Bcl-2 expression and esophageal tumors (P.value=0.239). Out of five samples expressing Bcl-2, four (8%) of them were squamous cell carcinoma and only one (2%) was adenocarcinoma with no statistical association between Bcl-2 expression and type of cancer (P.value=0.738). Comparing the expression of bcl-2 and the grade of the tumor the positive result was detected in 2 (4%) samples of moderately differentiated tumors and 3 (6%) samples of poorly differentiated tumors with no relation between the histologic grade of tumor and Bcl-2 expression (P.value=0.857). In this study the expression of the two markers was P53 -/bcl-2- in 26 (52%) samples, P53+/bcl-2 - in 19 (38%) samples, P53-/bcl2 + in 1(2%) samples, P53+/bcl2 + in 4 (8%) samples .We found that no correlation between the expression of p53 and bcl-2 in esophageal tumor. This study concludes that there is association between P53 expression and malignant tumors of esophagus, with no association with type of tumor while the expression of P53 is associated with histological differentiation of tumor. Bcl-2 expression is not associated with both type of tumor and the histological grade of tumor and there is no correlation between the expression of P53 and Bcl-2 in esophageal tumors.