Changes in molecular forms of prostate-specific antigen during treatment with finasteride

[5ARI and PSA: evidences]

OBJECTIVE

The 5alpha-reductase inhibitors (5ARIs) represent a valid therapeutic option in the long-term treatment of benign prostatic hyperplasia (BPH). One of the most debated topics is the interpretation of the variation of the serum PSA during treatment with 5ARIs. The objective of this review was to analyze the change in serum PSA levels over time and to evaluate its sensitivity and specificity in the screening for prostate cancer (CaP) during treatment.

METHODS

An extensive search using PubMed and Scopus was performed including the following key words: "5ARI", "finasteride", "dutasteride", "prostate cancer", "benign prostatic hyperplasia", "PSA", "kinetics", "PSA derivatives".

RESULTS

The reduction of serum PSA during treatment with 5ARIs can be observed up to 48 months after the beginning of the therapy. This category of drugs seems to improve the diagnostic performance of PSA in screening CaP. On the other hand, there is a reduction of the diagnosis of indolent cancers. Any increase in PSA from nadir should be considered suspicious for malignancy. However, if the choice of a biopsy depended only on an increase of the values of serum PSA, a variable percentage of potentially aggressive tumors could not be diagnosed. Therefore, it is important to consider in the clinical and diagnostic follow-up other factors such as digital rectal examination, age, family history of CaP and imaging techniques.

CONCLUSIONS

5-ARIs have a positive impact on the specificity of PSA but they must not be the only tool that can identify CaPs with poor prognosis.

Detection rate of clinically insignificant prostate cancer increases with repeat prostate biopsies

To analyze if clinically insignificant prostate cancer (CIPC) is more frequently detected with repeat prostate biopsies, we retrospectively analyzed the records of 2146 men diagnosed with prostate cancer after one or more prostate biopsies. The patients were divided into five groups according to the number of prostate biopsies obtained, e.g. group 1 had one biopsy, group 2 had two biopsies and group 3 had three biopsies. Of the 2146 patients diagnosed with prostate cancer, 1956 (91.1%), 142 (6.6%), 38 (1.8%), 9 (0.4%) and 1 (0.1%) men were in groups 1, 2, 3, 4 and 5, respectively. Groups 4 and 5 were excluded because of the small sample sizes. The remaining three groups (groups 1, 2 and 3) were statistically analyzed. There were no differences in age or prostate-specific antigen level among the three groups. CIPC was detected in 201 (10.3%), 28 (19.7%) and 9 (23.7%) patients in groups 1, 2 and 3, respectively (P<0.001). A multivariate analysis showed that the number of biopsies was an independent predictor to detect CIPC (OR=2.688 for group 2; OR=4.723 for group 3). In conclusion, patients undergoing multiple prostate biopsies are more likely to be diagnosed with CIPC than those who only undergo one biopsy. However, the risk still exists that the patient could have clinically significant prostate cancer. Therefore, when counseling patients with regard to serial repeat biopsies, the possibility of prostate cancer overdiagnosis and overtreatment must be balanced with the continued risk of clinically significant disease.

The different reduction rate of prostate-specific antigen in dutasteride and finasteride

Purpose

To compare and analyze the therapeutic effects and changes in the prostate-specific antigen (PSA) level with treatment with finasteride or dutasteride for benign prostatic hyperplasia (BPH) for 1 year.

Materials and Methods

We retrospectively investigated patients who suffered from BPH for 1 year between January 2005 and December 2008. For treatment groups, we divided the patients into two groups: one was treated with alfuzosin and finasteride and the other was treated with alfuzosin and dutasteride. At the beginning of treatment, the patients underwent transrectal ultrasonography and measurement of urine flow rate, residual urine volume, PSA, and International Prostate Symptom Score (IPSS). Patients with diseases affecting urinary function were excluded. We not only analyzed the data at the time of initial treatment, but also after 1 year of treatment. A total of 219 patients were able to be evaluated for 1 year.

Results

Both finasteride and dutasteride reduced PSA and prostate volume significantly. The comparison between groups showed a more significant reduction of PSA (p=0.020) and prostate volume (p=0.052) in the dutasteride group. Other parameters did not differ significantly between the groups.

Conclusions

5-α Reductase inhibitors for BPH treatment reduced PSA and prostate volume significantly when the patients were treated for 1 year. Administration of dutasteride is considered to be more effective in reducing PSA and prostate volume. Therefore, dutasteride should not be considered equivalent to finasteride in the reduction rate of PSA. The intensity of dutasteride must be reevaluated in comparison with finasteride.

Medical treatment of benign prostatic hyperplasia

Pharmaceutical preparations are commonly used for benign prostate hyperplasia. This article reviews the current understanding of the natural history of the condition and the literature regarding medical treatment.

Prostate cancer risk among users of finasteride and alpha-blockers - a population based case-control study

Finasteride has been reported to reduce prostate cancer risk in asymptomatic men. However, in clinical practice finasteride and alpha-blockers are used to treat benign prostatic hyperplasia (BPH). We evaluated prostate cancer risk among users of BPH pharmacotherapy at the population level. Comprehensive Finnish national registries provided information on 24723 prostate cancer cases and controls. Overall, prostate cancer risk was elevated among users of both drug categories compared to non-users (odds ratio, OR=1.41; 95% confidence interval, CI 1.31-1.51 for finasteride and OR=1.79; 95% CI 1.67-1.91 for alpha-blockers). However, the risk was lower among finasteride users when compared with alpha-blocker users (OR=0.80; 95% CI 0.64-1.00). Regular finasteride users had the lowest risk. The increased risk is probably due to enhanced diagnostics of prostate cancer in men with BPH. Finasteride use does not decrease prostate cancer incidence compared with non-users. Nevertheless, the risk is lower when compared with alpha-blocker users.

Serum pro prostate specific antigen improves cancer detection compared to free and complexed prostate specific antigen in men with prostate specific antigen 2 to 4 ng/ml

PURPOSE

Pro prostate specific antigen (pPSA) is a precursor form of PSA enriched in tumor compared to benign prostate tissues that may be a more specific serum marker for prostate cancer. Serum pPSA was measured in the clinically relevant early detection PSA range of 2 to 10 ng/ml.

MATERIALS AND METHODS

Research use immunoassays were used to measure native and truncated forms of pPSA. The subject cohort contained 1,091 serum specimens from men enrolled in prostate cancer screening studies at 2 sites who had undergone prostate biopsy and were divided into PSA ranges of 2 to 4 ng/ml (benign 320, cancer 235) and 4 to 10 ng/ml (benign 315, cancer 221).

RESULTS

In PSA ranges 2 to 4, 2 to 6, 4 to 10 and 2 to 10 ng/ml, pPSA in a ratio with free PSA (%pPSA) gave the highest cancer specificity. At 2 to 4 ng/ml and 90% sensitivity, %pPSA spared 19% of unnecessary biopsies compared to 10% for free PSA and 11% for complexed PSA(p <0.001). Similar results were obtained at PSA 2 to 6 ng/ml. At 90% sensitivity in the PSA 4 to 10 ng/ml range, %pPSA spared 31% of unnecessary biopsies compared to 20% for % free PSA and 19% for complexed PSA (p <0.0001). In the combined 2 to 10 ng/ml range, %pPSA spared 21% of unnecessary biopsies compared to 13% for % free PSA and 9% for complexed PSA (p <0.0001).

CONCLUSIONS

The %pPSA significantly improved specificity for cancer detection and decreased the number of unnecessary biopsies in the PSA 2 to 4 ng/ml range. This relative improvement of %pPSA compared to % free PSA and complexed PSA was maintained throughout the PSA range of 2 to 10 ng/ml.