Study of carcinoembryonic antigen and protein-bound sialic acid in prostatic cancer and benign prostatic hyperplasia

ABSTRACT

In this study, taking prostatic acid phosphatase [PAP] as a reference, two tumor markers [serum carcinoembryonic antigen [CEA] and serum protein bound sialic acid [NANA]] were estimated to evaluate their role in diagnosis, staging as well as monitoring of the therapeutic response of prostatic cancer. The study was carried out on 19 prostatic cancer patients, 10 patients with benign prostatic hyperplasia and 10 healthy males as controls. All of them were subjected to the estimation of serum PAP, CEA and NANA before treatment and one month after treatment [orchiectomy for prostatic cancer patients and transurethral resection of prostate in cases with benign prostatic hyperplasia]. The results of the present study revealed that CEA NANA and PAP were significantly elevated in prostatic cancer patients as compared to both controls and patients with benign prostatic hyperplasia [BPH]. The three tumor markers gave sensitivities of 68.4%, 84.2% and 57.8%, respectively, for the diagnosis of prostatic cancer. This finding showed that serum NANA is the most sensitive of the three markers, an observation that needs further proof in view of the small number of cases studied. The three markers showed specificities of 80%, 80% and 90%, respectively, in diagnosis of prostatic, cancer. So, PAP is proved to be the most specific for prostatic cancer, serum CEA and NANA being only nonspecific markers. The present study revealed also that NANA was significantly increased with the progression of the stage of cancer, while CEA levels showed insignificant increase with the advancement of the cancer stage. This finding was explained by the fact that serum CEA is related to the grade of differentiation of the tumor cells [grading] more than with staging. Serum PAP was found to be increased significantly in the late stages only [stage C and D]. So, serum PAP is considered to be a marker for prostatic cancer with metastasis and that it has a minor importance on early stage [stage A and B]. Although serum PAP was the reference marker in this study, it only showed insignificant decrease in cancer patients following therapy, which may be explained by the small number of cases and the wide range of its levels in these cases. Serum values of CEA and NANA showed significant reduction after treatment in prostatic cancer patients. Serum PAP levels showed a significant positive correlation with serum NANA in prostatic cancer patients before and after treatment. From these previous results, it was concluded that the use of more than one marker cooperatively helps in monitoring the therapeutic response of patients with prostatic cancer