Evaluation of the Validity of Some Tumor Markers in the Identification and Differential Diagnosis of Prostate Tumors

Abstract

This is a hospital base longitudinal descriptive study aimed to evaluate the validity of PSA, CEA, Her2, BcL2, P53 and HMW cytokeratin tumor markers in the identification and differential diagnosis of prostate tumors. The study was conducted in Khartoum, Soba, and Ibnsina hospitals during the period form July 2006 to July 2008. One hundred biopsies and venous blood samples were randomly collected from patients presenting with prostate tumors. Tissue sections were stained using two methods, histochemical method using haematoxylin and Eosin technique for histopathological diagnosis, and immunohistochemical method using avidin biotin technique immunohistochemical for tumor markers detection. Blood samples were used for estimation of circulating PSA and CEA tumor markers using Radio Immuno Assay (RIA) technique. The obtained Data were analyzed using SPSS computer program. Out of the 100 patients with prostatic lesions, histopathological diagnosis revealed benign prostatic hyperplasia in 25 patients, well differentiated adenocarcinoma in 42 patients and poorly differentiated adenocarcinoma in 33 patients. Positive PSA levels were found to be in 34 patients. Depending on the histopathology as gold standard the specificity, sensitivity, positive predictive value and negative predictive value of serum PSA were found as (80%), (45%), (85%), and (30%) respectively. Tissue PSA was positive in 96 patients distributed as follows 23 patients were diagnosed as BPH, 41 patients were diagnosed as well differentiated adenocarcinoma and 32 patients were diagnosed as poorly differentiated adenocarcinoma. Depending on the histopathology as golden standard the specificity, sensitivity, positive predicative value and negative predictive value of tissue PSA were found as follow (8%) (98%), (76%) and (50%) respectively. Nineteen patients were found to be positive with CEA levels, which distributed as follows three patients were diagnosed as BPH , eight patients were diagnosed as well differentiated adenocarcinoma and eight patients were diagnosed as poorly differentiated adenocarcinoma, with specificity, sensitivity, positive predictive value and negative predictive value as follow (88%), (25%), (84%) and (27%) respectively. The tissue expressions of CEA were found to be positive in 28 patients. Out of 28 patients with positive CEA expression, 16 patients were diagnosed as BPH, 11 patients were diagnosed as well differentiated adenocarcinoma and only one patient was diagnosed as poorly differentiated adenocarcinoma, with specificity, sensitivity, positive predictive value and negative predictive value as follow (16%), (64%), (20%) and (27%) respectively. P53 was detected in 49 patients, distributed as follow 17 patients were diagnosed as BPH, 29 patients were diagnosed as poorly differentiated adenocarcinoma and three patients were diagnosed as well differentiated adenocarcinoma, with significant correlation between P53 expression and prostate cancer the P value <0.01, with specificity, sensitivity, positive predictive value and negative predictive value as follow (88%), (61%), (93%) and (43%) respectively. HMW cytokeratin was detected in 32 patients, distributed as follow: 20 patients were diagnosed as BPH, nine patients were diagnosed as well differentiated adenocarcinoma and three patients were diagnosed as poorly differentiated adenocarcinoma, with significant correlation between HMW cytokeratin expression and prostate cancer the P value <0.01. The specificity, sensitivity, positive predictive value and negative predictive value of HMW cytokeratin were found as follow (84%), (80%), (63%) and (93%) respectively. The relation between serum levels and tissues expression of PSA and CEA markers were statistically insignificant, the P value > 0.01. The study showed that there is no significant relation between prostate cancer and tissues expression of Her2 and bcl2 tumor markers. Out of 100 patients with prostate lesion 62 patients were tobacco users, distributed as follow six patients were diagnosed as BPH and 56 patients were diagnosed as prostatic adenocarcinoma, with significant correlation between tobacco using and prostate cancer the P value >0.01. The study found that there was no significant relation between prostate cancer and family history, number of wives and alcohol consumption. As a conclusion of this study, histopathology still represents the golden standard for specific diagnosis of prostate lesions. PSA and CEA serum levels are insignificant for early defection of prostate cancer. PSA, BcL2, and Her2 tumor markers are invalid in the differential diagnosis of prostate lesions. P53, CEA and HMW cytokeratin tumor markers can be useful in the differential diagnosis of prostate lesions.