Evaluation of Three Different Tumor Markers for Diagnosis of Prostate Cancer, among Sudanese Patients. A study in Khartoum State, Sudan

Abstract

Prostate cancer is one of the world’s major killers and has a high morbidity and mortality rates. The aim of this study is to assess the specificity and sensitivity of different markers used in the diagnosis of prostate cancer. A cross sectional study conducted during the period from January 2011 to July 2013 to determine and evaluate the serum levels of early prostate cancer antigen-2, prostate specific antigen and prostatic acid phosphatase as diagnostic markers for prostate cancer in Sudanese patients. Two hundred Sudanese with prostate tumor (132 with prostate cancer and 68 with benign prostate hyperplasia) were selected as a test group from two teaching hospitals (Omdurman and Suba) in Khartoum state, Sudan. The test group was compared with a control group which included 100 apparently healthy male volunteers. Blood specimens were collected from both groups, and the serum levels of early prostate cancer antigen-2, prostate specific antigen and prostatic acid phosphatase were determined. Age of the test group was matched with the control group. The serum levels of early prostate cancer antigen-2 was measured using sandwich ELISA and the serum levels of prostate specific antigen was measured using Full automated analyzer (Elecsys 2010). Serum prostatic acid phosphatase was measured using a spectrophotomeric technique. Statistical Package for Social Science (SPSS version 17) computer software was used for data analysis. The results of this study revealed significant elevated means of the serum levels of early prostate cancer antigen-2, prostate specific antigen and prostatic acid phosphatase of the test group when compared with the control group. The results of this study also indicate higher sensitivity, specificity, positive predictive value and negative predictive value for early prostate cancer antigen-2 (93.2%, 88.2%, 93% and 86%) respectively when compared to prostate specific antigen (67%, 66%,79% and 52%) respectively; whereas for the prostatic acid phosphatase were found to be (36%, 54%, 60% and 30%) respectively. The results of this study also indicate significant elevations of the means of the serum levels of early prostate cancer antigen-2 and prostate specific antigen among the four different stages of prostate cancer among prostate cancer patients. The means of the serum levels of early prostate cancer antigen-2; prostate specific antigen and prostatic acid phosphatase in the results of this study were significantly increased among patients with prostate cancer when compared with control group. The results of this study showed that the means of the serum levels of early prostate cancer antigen-2 and prostate specific antigen were significantly raised in patients with late stages when compared with those in early stages of prostate cancer. Whereas no significant different in the mean serum levels of prostatic acid phosphatase. The current study indicates significant weak positive correlations between the duration of the prostate cancer since detection (in years) and the serum levels of early prostate cancer antigen-2, prostate specific antigen and prostatic acid phosphatase. In conclusion; the current study indicates that; measuring the serum levels of EPCA-2 is the most important, specific and sensitive marker for evaluation of prostate cancer, because its mean serum levels was significantly raised among patients with prostate cancer and positively correlated with the duration of cancer and more specific and sensitive when compared to prostate specific antigen and prostatic acid phosphatase. So it is recommended that; EPCA-2 can be used as a prognostic marker, for early prediction and follow up in patients with prostate cancer. Prostate specific antigen can also be used as a predictive and diagnostic marker but it is less sensitive and specific compared to EPCA-2.