Preliminary Results of Clinical Evaluation of the Free/Total Prostate-Specific Antigen Ratio in a Multicentric Study

Aims and Background

The free/total (F/T) prostate-specific antigen (PSA) ratio is probably the most promising tool proposed to increase the specificity of PSA in the diagnosis of prostate cancer. The aim of the present study was to evaluate the clinical value of the F/T ratio in 138 patients with benign hyperplasia, 101 with untreated prostate cancer, and 176 apparently healthy men.

Methods

We used a new immunometric assay of free PSA (FPSA-RIACT, CIS Diagnostici, Italy) which has shown good analytical performance; sample handling and storage under routine conditions did not affect the antigen stability.

Results

The diagnostic efficiency of the F/T ratio was significantly better than that of total PSA. In patients with total PSA ranging from 4 to 10 ng/ml, at a specificity level of 95% total PSA showed a sensitivity of 7%, whereas the sensitivity of F/T increased to 70%. Using the F/T ratio as a decision tool in association with total PSA and considering all cases candidate to biopsy (total PSA greater than 3.79 ng/ml corresponding to the 95% level), we demonstrated a 35% reduction of total biopsies that would have been required on the basis of total PSA alone.

Conclusions

The determination of the percentage of F/T serum PSA significantly improves the specificity of the marker, particularly in the 4-10 ng/ml dose range where unnecessary prostate biopsies can be reduced.

[Twelve years of ureterorenoscopy: evolution of the technique]

In the last ten years the diagnostic and therapeutical approach to ureteral neoplasms and stones changed their feature, due to improvement of the ureteroscopy. The passage through flexible to rigid and finally semirigid ureteroscopes permitted reduction of invasiveness with higher results. The positive changes to the energy sources, in regard to cost-benefit, it was versus ballistic energy. Ureteroscopy should now be considered as a simple and safe technique, with minimal morbidity and invasiveness and also short operative times.

[Comparison of free/total PSA (F/T PSA) ratio and PSA density (PSAD) in the early diagnosis of cancer of the prostate]

The identification of the immuno reactive molecular forms of PSA has permitted the identification of a correlation between Free PSA and Total PSA as the most important factor in the early diagnosis of prostate cancer. Cut-off of 0.15 ng/ml seems to be the most appropriate. The Authors consider that the use of this limit is important in the decision to carry out a prostate biopsy on the patients with PSA in the range of 4-10 ng/ml who have neither any clinical symptoms nor an abnormal transrectal ultrasound. In particular the sensitivity and the specificity of F/T PSA and the density of PSA (PSAD) have been compared at his limit of 0.15. In our study of 60 patients (of whom 22 were affected by cancer and 38 by BPH) we have noticed that 27/60 patients had a value of PSA between 4 and 10 ng/ml and negative DRE and TRUS. On the whole the F/T PSA report showed a slightly higher specificity than PSAD; in contrast PSAD showed a slightly higher sensitivity. In conclusion, to identify the early detection of this cancer both tests are required as well as a biopsy.

[Urinary PSA (uPSA) in the monitoring of local recurrence following radical prostatectomy]

The level of urinary PSA (PSAu) was measured for use as a marker in some clinical situations involving prostate cancer patients. Limits of physiological and pathological values, a quantity of which comes from the urethral glands and the umbilical median ligament (urachus), are still unknown. To establish the quantity of PSA secretion in the urethra, female PSAu was measured and found to be significantly low (< 0.1 ng/ml). The Authors report on 25 PR patients with negative margins and who had not received hormonal therapy for 30 months. The PSAu and the PSAs were measured on the 30th and the 60th day, and every 3 months thereafter in the first year and every 6 months in the second year. In 5 cases we observed an increase of PSAu between the 5th and 18th months. In 3 cases the PSAs increased 2 to 6 months later compared to the PSAu. In these 3 cases the biopsy indicated the presence of a localized relapse. Therefore the Authors recommend measuring the PSAu (cut-off 0.1 ng/ml) in the follow-up of the PR patients because the measurement may both identify a localized relapse earlier than the PSAs and indicate the localized response to hormonal or radiotherapy.

[Proposal of a new transurethral method for repeated prostatic biopsy]

In many clinical situations a patient affected by pre-cancerous prostatic lesions, suspected cancer or true cancer (assessed through biopsies or incidentally) must undergo iterative bioptic examinations. Three groups can be sub-divided: A) Patients with no previous endoscopic resection. B) Patients with previous endoscopic resection for BPH. C) Patients with previous RP for cancer. A persistent clinical suspicion for high PSA, a bioptic assessment for Ca T1c or PIN belong to the first group. A suspected cancer in a patient who had already undergone TUR, or a T1a neoplasia assessed incidentally, or PIN found in the resected fragments constitute the second group. A suspected local relapse after a RP characterizes the third group. In 28 cases of these clinical diagnoses, we have applied a new method of bioptic trans-urethral sampling. We used an eco-reflectant, flexible needle and applied it under endoscopic vision to the transitional zone or to tissues of the already resected prostatic fossa. In the first case these biopsies were integrative of the usual randomized biopsies. If transrectal ultrasound had given evidence of altered structures, biopsy was carried out with selective ultrasound guided technique. This procedure has proved to be minimally invasive, easy to carry out and particularly adapted to bioptise zones that are easier to reach transurethrally or tissues with low thickness.