Applications of Cytokeratin5/6 in Differential Diagnosis of Prostate Tumors

Abstract

This is a descriptive retrospective study aimed at evaluating the role of cytokeratin (CK 5/6) in differential diagnosis of prostate tumors by histochemical and immunohistochemical methods during the period from May 2012 to November 2012. Sixty paraffin blocks were taken from patients with prostate tumor attending to Radio Isotope Center in Khartoum by using simple random selection method. Sections were stained using two methods, histochemical method using haematoxylin and eosin for histopathology diagnosis, and immunohistochemical using dextran labeled polymer technique to detect an expression of cytokeratin5/6 in prostate tumor patients. The age of study population ranged between 50 to 83 years old with a mean age of 67 years. The study revealed that the majority of patients were older than 60 years representing 48 (80%) and the remaining 12 (20%) were younger than 60 years. Out of 60 patients, histological diagnosis revealed benign prostatic hyperplasia in 30 (50%) patients, and malignant prostate in 30 (50%) patients. In this study histopathological grading of cancer showed well differentiated adenocarcinoma in 2 (3.3%) patients, moderately differentiated in 10 (16.7%) patients, and poorly differentiated in 18 (30%) patients. In this study, CK5/6 expression among study population represents 28 (46.7%) patients were positively expressed CK5/6, and the remaining 32 (53.3%) patients were negative for CK5/6. Histopathological diagnosis and CK5/6 expression showed that positive in 26 (43.3%), and negative in 4 (6.7%) patients among benign prostatic hyperplasia. 2 (3.3%) positive patients and 28 (46.6%) negative patients among adenocarcinoma of prostate with significant statistical association (P value < 0.05). In this study the relationship between the expression of CK5/6 and age group showed that, ages less than 60 years were positive in 6 (10%) patients, and negative in 6 (10%) patients, ages older than 60 years were positive in 22 (36.7%) patients and negative in 26 (43.3%) patients. The study revealed that there is no association between the age and the expression of CK 5/6 (P. value > 0.05). Two out of twelve patients (16.7%) at age less than 60 years were diagnosed with moderately differentiated adenocarcinoma and no one diagnosed with well differentiated, 4 (33.3%) patients with poorly differentiated, 6 (50%) patients were diagnosed with benign hyperplasia. Age older than 60 years, 2 (16.6%) out of 48 patients were diagnosed with well differentiated, 8 (13.3%) were diagnosed with moderately differentiated, and 14 (23.3%) patients were poorly differentiated, 24 (50%) patients were diagnosed with benign hyperplasia. The study revealed that there is no association between the age and histological diagnosis (P value > 0.05). On the basis of this findings it is concluded that there was significant statistical association between expression of CK5/6 and prostate tumor. CK5/6 positively expressed among benign prostate tumors and negatively expressed among malignant prostate tumors.