Prostate specific antigen ratio: for diagnosis and assessment of aggressiveness of malignancy of prostate.

The search for a perfect tumour marker, which would be able to distinguish benign from malignant enlargement of prostate accurately, is still not complete. Total Prostate Specific Antigen (TPSA), a good test, has it's own inadequacies but Free Prostate Specific Antigen (FPSA) to TPSA ratio is emerging as a better adjuvant to it. This prospective study was done to verify the utility of FPSA to TPSA ratio in diagnosis of malignancy of prostate and its relationship to Gleason grading (indicating the aggressiveness) of adenocarcinoma of prostate. 100 patients with urinary symptoms, who were above fifty years of age and had prostatic enlargement, formed the study group. TPSA and FPSA were assayed by ELISA method and FPSA to TPSA ratio was calculated. Prostatic biopsy of all the cases was obtained and diagnostic histopathology and Gleason grading (in cases where adenocarcinoma was diagnosed) was done. Sensitivity, specificity, predictive value of positive test and predictive value of negative test for TPSA and FPSA to TPSA ratio were calculated. They were found to be 100%, 76.7%, 74.1% and 100% for TPSA and 82%, 100%, 100%, 89% for FPSA/TPSA ratio. Thus making it very obvious that FPSA to TPSA ratio is an excellent adjuvant to TPSA for diagnosis of malignancy of prostate increasing the specificity and predictive value for positive test. An inverse correlation (correlation coefficient = -0.95) was also found between PSA ratio and aggressiveness of prostate cancer, pointing towards its capability to predict the histological (Gleason) grade of the tumour.

Diagnosis of malignancy of prostate.

Minimal or complete lack of symptoms hinders early diagnosis of malignancy of prostate leading to undue morbidity and mortality. Therefore early detection is imperative, making use of simple and safe technique with least of expense. Five hundred consecutive patients, who reported with urinary complaints, were assessed by digital rectal examination, transabdominal suprapubic ultrasonography for prostatic volume/weight and serum assay of prostate specific antigen (PSA). Histopathological examination of prostatic biopsy of all the cases was also done. Benign prostatic hyperplasia was found in 83.6% of cases and 16.4% of the cases were of adenocarcinoma prostate of varying severity (mild, moderate and severe). It was found that volume/weight of gland and PSA levels were very good indicators of the probable diagnosis and grade of adenocarcinoma. Statistical tests taking various levels of PSA values in account also validated the results.