PSA response to finasteride challenge in men with a serum PSA greater than 4 ng/ml and previous negative prostate biopsy: preliminary study

Prostate-specific antigen density during dutasteride treatment for 1 year predicts the presence of prostate cancer in benign prostatic hyperplasia after the first negative biopsy (PREDICT study)

OBJECTIVES

To prospectively evaluate the detection rate of prostate cancer, and to identify the risk factors of prostate cancer detection after a 1-year administration of dutasteride and first negative prostate biopsy.

METHODS

Patients with benign prostatic hyperplasia who presented high prostate-specific antigen levels after the first negative prostate biopsy were administered 0.5 mg dutasteride daily for 1 year. They underwent a repeat prostate biopsy after 1 year. The primary end-point was the detection rate of prostate cancer. The secondary end-point was the ability of prostate-specific antigen kinetics to predict prostate cancer detection. Prostate-specific antigen was measured before the initial prostate biopsy and at 6, 9 and 12 months after starting dutasteride. Patients were classified into a prostate cancer and a non-prostate cancer group.

RESULTS

Prostate cancer was detected in 15 of 149 participants (10.1%). The total prostate-specific antigen change between the prostate cancer and non-prostate cancer group at 1 year was significantly different (P = 0.002). Although prostate-specific antigen levels at baseline did not significantly differ between study groups (P = 0.102), prostate-specific antigen levels at 6, 9 and 12 months were significantly different (P = 0.002, P = 0.001 and P < 0.001, respectively). The mean reduction rate of prostate-specific antigen density between the prostate cancer and non-prostate cancer group at 1 year was significantly different (-4.25 ± 76.5% vs -38.0 ± 28.7%, P = 0.001). Using a multivariate analysis, a >10% increase of prostate-specific antigen density at 1 year post-dutasteride treatment was the only predictive risk factor for prostate cancer after the first negative prostate biopsy (odds ratio 11.238, 95% confidence interval 3.112-40.577, P < 0.001).

CONCLUSION

In the present study cohort, >10% increase in prostate-specific antigen density represented the only significant predictive risk factor for prostate cancer diagnosis in patients with elevated prostate-specific antigen after the first negative prostate biopsy.

The effect of 3-month finasteride challenge on biomarkers for predicting cancer outcome on biopsy: Results of a randomized trial

BACKGROUND

Finasteride, a 5-alpha reductase inhibitor may have effects on biomarkers such as prostate-specific antigen (PSA) that could be leveraged to improve screening.

OBJECTIVE

To determine the predictive characteristics of biomarkers for prostate cancer for cancer on biopsy following 3 months of finasteride use compared with placebo.

DESIGN, SETTING AND PARTICIPANTS

383 men from multiple clinical sites with intermediate prostate cancer risk, without history of prostate cancer, were randomly allocated in a double-blinded manner, 4:1, to receive either finasteride or placebo for 90 days at which time a prostate biopsy was performed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcomes were associations of biomarkers with prostate cancer that were tested using multiple logistic regression and area under the receiver operating curves (AUC). Biomarkers for PCA risk (PCA3, TMPRSS2:ERG (T2:ERG) gene product, and PSA) were measured at baseline and at biopsy in a blinded fashion to assess the predictive performance of baseline levels, 90-day levels, and measures of change relative to standard predictors.

RESULTS AND LIMITATIONS

A total of 292 (233 finasteride; 59 placebo) randomized patients underwent biopsy and were analyzed. On finasteride, baseline and 90-day measures of PCA3 and T2:ERG had similar moderate discrimination capacity with AUCs 62 to 65% (p-values < 0.001 and 0.001, respectively), but their rates of change had no discrimination ability (AUC 51%, (95% CI 43 to 60% p = 0.72) and 48% (95% CI 44 to 60%, p = 0.62), respectively).) Relative to baseline, the 90-day PCA3 and PSA decreased in the finasteride group by 25% and 50%, respectively (both p<0.001). T2:ERG had a smaller, non-significant change post finasteride treatment (p = 0.08).

CONCLUSIONS

Short-term finasteride therapy did not improve performance of the most commonly-employed prostate cancer biomarkers. Threshold values for new biomarkers of prostate cancer should be interpreted with caution in patients receiving finasteride until formal validation of test performance in these patients is conducted.

PATIENT SUMMARY

Three months of finasteride treatment did not increase the accuracy for predicting the outcome on prostate biopsy but did have a significant effect on biomarker values. Adjustments to thresholds for biopsy for men on finasteride are proposed.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01296672.

[Prostate cancer detection rates: comparison of standard biopsy with prompt rebiopsy and a one-time extended biopsy]

INTRODUCTION

Prostate biopsy is the gold standard for the detection of prostate cancer (PCA). While national and international guidelines recommend the extraction of 10-12 cores at initial biopsy, some authors plead to initially perform more extensive biopsy protocols. We assessed the PCA detection and complication rates of different biopsy schemes.

MATERIALS AND METHODS

We relied on the data of 425 men who underwent their first prostate biopsy from April 2005 to May 2013. Exclusion criteria consisted of PSA > 20 ng/ml, prior surgery of the prostate, or intake of 5-α-reductase inhibitors. Overall 357 underwent a 10- to 12-core biopsy, while 68 patients underwent 20-core biopsy. In case of a negative biopsy in the 10-12 cohort, rebiopsy was performed within 6 months, while in the 20-core group clinical follow-up determined further course of action. Endpoints of the study were the overall PCA detection rate and the rate of severe complications, which were defined as complications requiring hospital admission. The effect of the respective biopsy scheme on the PCA detection rate was assessed using uni- and multivariable logistic regression analysis. In the subanalysis, the PCA detection rates between the two groups were compared solely in patients with PSA values ≤10 ng/ml.

RESULTS

At initial biopsy, the overall PCA detection rate was 50.4% (214/425). In the 10-12 core group, the PCA detection rate at first biopsy was 52.4% (187/357) and rebiopsy detected a further 19 (11.2%) PCA cases, resulting in a cumulative PCA detection rate of 57.7% (206/357). In the 20-core group, the PCA detection rate was 39.7% (27/68). While the different PCA detection rates were not statistically different when the initial biopsies were compared, biopsy scheme reached independent predictor status when the cumulative PCA detection rate of the 10- to 12-core scheme was compared to the 20-core scheme (p=0.01). Comparable results were obtained only when patients with PSA ≤10 ng/ml were considered. The rate of severe complications was statistically higher in the 20-core group (6.1 vs. 2.4%; p=0.01).

CONCLUSION

Our data indicate that an initial 20-core biopsy does not lead to a higher PCA detection rate compared to an initial 10- to 12-core biopsy. Moreover, the cumulative PCA detection rate of a 10- to 12-core biopsy and prompt repeat biopsy was significantly higher compared to a single 20-core biopsy.

Clinical effects of discontinuing 5-alpha reductase inhibitor in patients with benign prostatic hyperplasia

PURPOSE

To assess changes in lower urinary tract symptoms (LUTS), prostate volume, and serum prostate-specific antigen (PSA) after discontinuation of 5-alpha reductase inhibitor (5ARI) combination therapy in patients with benign prostatic hyperplasia (BPH).

MATERIALS AND METHODS

From December 2003 to December 2012, data were collected retrospectively from 81 men more than 40 years of age with moderate to severe BPH symptoms (International Prostate Symptom Score [IPSS]≥8). The men were classified into group 1 (n=42) and group 2 (n=39) according to the use of 5ARI therapy. A combination of dutasteride 0.5 mg with tamsulosin 0.2 mg was given daily to all patients for 1 year. For the next 1 year, group 1 (n=42) received the combination therapy and group 2 (n=39) received tamsulosin 0.2 mg monotherapy only. The IPSS, prostate volume, and PSA level were measured at baseline and at 12 and 24 months according to the use of dutasteride.

RESULTS

Discontinuation of dutasteride led to significant deterioration of LUTS, increased prostate volume, and increased PSA level. The repeated-measures analysis of variance showed that the changes in IPSS, prostate volume, and PSA level over time also differed significantly between groups 1 and 2 (p<0.001).

CONCLUSIONS

Withdrawal of 5ARI during combination therapy resulted in prostate regrowth and deterioration of LUTS. The PSA level is also affected by the use of 5ARI. Therefore, regular check-up of the IPSS and PSA level may be helpful for all patients who either continue or discontinue the use of 5ARI.

Prostate biopsy in response to a change in nadir prostate specific antigen of 0.4 ng/ml after treatment with 5α-reductase inhibitors markedly enhances the detection rate of prostate cancer

PURPOSE

We examined the effect of 5α-reductase inhibitor therapy on prostate cancer detection in men with persistently increased or fluctuating prostate specific antigen and prior negative prostate cancer biopsy.

MATERIALS AND METHODS

A total of 276 men with prostate specific antigen greater than 4 ng/ml (208) or a prostate specific antigen velocity change of 0.75 ng/ml (68) and a normal digital rectal examination who had previously undergone biopsy a minimum of 2 times with prostate cancer not detected were given 5 mg finasteride (154) or dutasteride (122) daily. In phase 1, 97 patients had prostate specific antigen measured at 6 and 12 months with repeat transrectal ultrasonography and biopsy (12 cores) performed at 1 year. In phase 2, 179 patients underwent biopsy triggered by a change in nadir prostate specific antigen of more than 0.4 ng/ml.

RESULTS

In phase 1 at 1 year prostate specific antigen had decreased by 2.4 ng/ml (-46.7%), and prostate volume had decreased 7.1 ml (-17.9%). Prostate cancer was detected in 27 of 97 (27.8%) patients and the mean minimum prostate specific antigen velocity from a nadir of 0.4 ng/ml was 0.6 ng/ml. In phase 2, 48 of 179 (26.8%) men underwent repeat biopsy at a mean of 14.6 months. Of these 48 men 26 (54.1%) were found to have prostate cancer. Of the 26 men in whom prostate cancer was detected 20 (76.9%) were found to have Gleason score 7 or greater disease.

CONCLUSIONS

The magnitude of change in serum prostate specific antigen after 5α-reductase inhibitor therapy may be useful in diagnosing prostate cancer in patients with persistently increased or fluctuating prostate specific antigen and prior negative prostate biopsy.

A broader role for 5ARIs in prostate disease? Existing evidence and emerging benefits

5ARIs are recommended for men who have moderate-to-severe lower urinary tract symptoms (LUTS) and benign prostatic enlargement (BPE) secondary to benign prostatic hyperplasia. Studies have confirmed the utility of combining 5ARIs with alpha-blockers; the MTOPS study showed that risk of overall clinical progression was significantly reduced after 4.5 years with combination therapy (finasteride/doxazosin) in comparison with either monotherapy, while the ongoing CombAT trial (dutasteride/tamsulosin) has for the first time shown benefit in improving symptoms for combination therapy over monotherapies within 12 months of treatment. Data also suggest roles for 5ARIs in prostate cancer. Several studies indicate that treatment with a 5ARI improves the performance of PSA testing for identifying men with prostate cancer, while the PCPT showed a significant reduction in the risk of developing prostate cancer with finasteride. However, widespread use of finasteride in this setting has been tempered by an apparent increase in high-grade disease observed in the study. The ongoing REDUCE study will provide further insight into prostate cancer prevention with 5ARIs. 5ARI-containing regimens may have utility as less aggressive treatment options for patients who only have rising PSA after definitive local therapy, and in patients with disease resistant to androgen deprivation therapy who have PSA progression. Current evidence therefore shows that 5ARIs are effective in treating LUTS/BPE and preventing disease progression, and may also have a role in the prevention of prostate cancer. The overlap between BPE and prostate cancer may allow a more unified approach to managing these conditions, with 5ARIs having a central role.

Detection bias due to the effect of finasteride on prostate volume: a modeling approach for analysis of the Prostate Cancer Prevention Trial

BACKGROUND

The Prostate Cancer Prevention Trial (PCPT) demonstrated a 24.8% reduction in the 7-year prevalence of prostate cancer among patients treated with finasteride (5 mg daily) compared with that among patients treated with placebo; however, a 25.5% increase in the prevalence of high-Gleason grade tumors was observed, the clinical significance of which is unknown. One hypothesized explanation for this increase is that finasteride reduced prostate volume, leading to detection of more high-grade tumors due to increased sampling density. This possibility was investigated in an observational reanalysis of the PCPT data, with adjustment for sampling density.

METHODS

A logistic model for the association of high-grade (Gleason score 7-10) prostate cancer with baseline covariates and/or baseline covariates plus prostate volume and number of cores obtained at biopsy was developed using the placebo group (n = 4775) of the PCPT. This model was then applied to the finasteride group (n = 5123) to compare the predicted and observed numbers of high-grade tumors in that group. In a second approach, odds ratios (ORs) for prostate cancer in the finasteride versus placebo groups calculated from binary and polytomous logistic regression models that contained or excluded covariates for gland volume and number of needle cores were compared.

RESULTS

Median prostate volume was 25% lower in the finasteride group (median = 25.1 cm3) than in the placebo group (median = 33.5 cm3). The logistic model developed in the placebo group showed that the likelihood of detection of high-grade prostate cancer decreased as volume increased (for each 10 cm3 increase in prostate volume, OR = 0.81, 95% confidence interval [CI] = 0.74 to 0.90). Based on this model, 239 high-grade prostate cancers were predicted in the finasteride group, whereas 243 were observed, a non-statistically significant difference. Among all participants, the odds ratios for high-grade cancer in the finasteride versus placebo groups decreased from 1.27 (95% CI = 1.05 to 1.54) with adjustment for baseline covariates to 1.03 (95% CI = 0.84 to 1.26) following additional adjustment for gland volume and number of biopsy cores in binary outcome models and from 1.14 (95% CI = 0.94 to 1.38) to 0.88 (95% CI = 0.72 to 1.09) following these adjustments in the polytomous models.

CONCLUSIONS

Although analyses using postrandomization data require cautious interpretation, these results suggest that sampling density bias alone could explain the excess of high-grade cancers among the finasteride-assigned participants in the PCPT.

Can effect of finasteride on prostate-specific antigen be used to decrease repeat prostate biopsy?

OBJECTIVES

Patients often undergo multiple prostate biopsies for persistently elevated prostate-specific antigen (PSA) levels. Finasteride decreases serum PSA by approximately 50%. We performed a pilot study to examine the correlation among finasteride, PSA, and PSA density (PSAD) to identify patients who could be excluded from repeat prostate biopsy.

METHODS

We performed a prospective study from 2001 to 2002 on 25 men with elevated PSA levels. These patients had prior negative prostate biopsy findings. At study onset, the patients' PSA level and PSAD were measured. Patients were instructed to take finasteride 5 mg for 6 months. PSA and PSAD determination and prostate biopsies were repeated at 6 months and the findings compared with the initial results.

RESULTS

The mean patient age was 67.2 years (median 62). The median PSA level was 8.3 ng/dL at study entry (mean 9.34) and 4.6 ng/dL (mean 5.09) at 6 months. The median PSAD was 0.18 (mean 0.20) at study entry and 0.09 (mean 0.12) at 6 months. Of the 23 patients who completed the study, 6 (26%) were diagnosed with prostate cancer. At study entry, the median PSA level in those with prostate cancer was 9.6 ng/dL and was 5.8 ng/dL at 6 months. Patients without prostate cancer on repeat biopsy had a 44% decrease in PSAD. Patients with prostate cancer had a 5% decrease in PSAD.

CONCLUSIONS

The results of our study have demonstrated that patients without prostate cancer have a greater decrease in PSAD when taking finasteride than those with prostate cancer. This pilot study had a small population with limited power, and a repeat prospective study with a larger population is warranted.

The interpretation of serum prostate specific antigen in men receiving 5alpha-reductase inhibitors: a review and clinical recommendations

PURPOSE

We reviewed the effects of 5alpha-reductase inhibitors on prostate specific antigen and clarified the adjustments that should be made to compensate for these effects to ensure that the usefulness of prostate specific antigen for detecting prostate cancer is maintained.

MATERIALS AND METHODS

We reviewed articles published in the scientific literature with relevance to the effects of 5alpha-reductase inhibitors on the usefulness of prostate specific antigen for detecting prostate cancer.

RESULTS

A total serum prostate specific antigen of 4.0 ng/ml has traditionally been used as the threshold for triggering prostate biopsy. However, clinical trials of finasteride and dutasteride have shown that 5alpha-reductase inhibitors decrease serum prostate specific antigen in patients with and without prostate cancer. To compensate, the doubling rule has been applied in clinical trials and clinical practice. However, doubling serum prostate specific antigen may overestimate actual prostate specific antigen in some patients receiving 5alpha-reductase inhibitors for up to 6 to 9 months, accurately estimate prostate specific antigen from 1 to 3 years and underestimate it thereafter. An increase in prostate specific antigen of 0.3 ng/ml from nadir as a trigger for biopsy maintains 71% sensitivity for prostate cancer in men receiving dutasteride with 60% specificity, similar to the 4.0 ng/ml prostate specific antigen cutoff using placebo.

CONCLUSIONS

We propose that a prostate specific antigen increase from nadir of 0.3 ng/ml or greater could represent an alternative to the doubling rule for monitoring prostate specific antigen in patients on 5alpha-reductase inhibitors. The prostate specific antigen increase from nadir appears to be a more accurate cancer indicator than a doubled value in some patients.

Effect of Finasteride on the Sensitivity of PSA for Detecting Prostate Cancer

BACKGROUND

In the Prostate Cancer Prevention Trial (PCPT), men receiving finasteride had a 24.8% lower risk of prostate cancer than men receiving placebo but a higher risk of high-grade cancer. We examined the impact of finasteride on the sensitivity and area under the receiver operating characteristic curve (AUC) of prostate-specific antigen (PSA) for detecting prostate cancer.

METHODS

We studied men in the placebo and finasteride groups of the PCPT who had a prostate biopsy and concurrent PSA tests during the 7-year study. We compared the placebo and finasteride groups for sensitivity and AUC of PSA for the detection of all prostate cancer, of Gleason grade 7 or higher prostate cancer, and of Gleason grade 8 or higher prostate cancer. All statistical tests were two-sided.

RESULTS

Of 5112 men in the placebo group, prostate cancer was detected in 1111. Gleason tumor grade was available for 1100 men, of whom 240 had grade 7 or higher and 55 had grade 8 or higher. Of 4579 men in the finasteride group, 695 had prostate cancer. Gleason grade was available for 686 men, of whom 264 had grade 7 or higher and 81 had grade 8 or higher. The AUC of PSA for all outcomes was greater for the finasteride group than the placebo group. For detecting prostate cancer versus no cancer, the AUCs were 0.757 and 0.681, respectively (P < .001); for detecting Gleason grade > or = 7 versus < or = 6 or no cancer, the AUCs were 0.838 and 0.781, respectively (P = .003); and for detecting Gleason grade > or = 8 versus < or = 7 or no cancer, the AUCs were 0.886 and 0.824, respectively (P = .071). The sensitivity of PSA was higher for men in the finasteride group than in the placebo group at all PSA cutoffs matched by specificity.

CONCLUSIONS

PSA had statistically significantly better sensitivity and AUC for detecting prostate cancer in the finasteride arm of the PCPT than in the placebo arm. This bias would be expected to contribute to greater detection of all grades of prostate cancer with finasteride.

Use of 5α-reductase inhibitors to prevent benign prostatic hyperplasia disease

A histologic change in the prostate, benign prostatic hyperplasia (BPH), is a normal part of aging. However, BPH disease, defined here as a life-altering urinary condition caused by BPH requiring prompt medical intervention, is a serious medical disorder associated with major complications, surgical intervention, and severe lifestyle interference. BPH disease is preventable. The rationale for BPH disease prevention rests on four pillars of evidence: (1) BPH disease generally is a progressive disorder; (2) complications and severe lifestyle interference from BPH disease are common and serious; (3) men at greatest risk of BPH disease can be identified using prostate-specific antigen (PSA) level higher than 1.5 ng/mL as a surrogate marker for an enlarged prostate; and (4) 5alpha-reductase inhibitors (5ARIs) reduce the primary androgen responsible for prostate growth (dihydrotestosterone), shrink the prostate, and arrest the disease process regardless of symptom status. Thus, we now can identify men with an enlarged prostate at risk for BPH disease who may be candidates for preventive therapy with 5ARIs, regardless of urinary symptoms or bother.

Intermittent use of testosterone inactivating pharmaceuticals using finasteride prolongs the time off period

PURPOSE

Men with prostate cancer treated intermittently with TIP benefit from improved quality of life when TOP with recovered testosterone is prolonged. We examined factors influencing the duration of TOP.

MATERIALS AND METHODS

We retrospectively reviewed the charts of 101 men treated with intermittent TIP in a 9-year period. Men with positive bone scan, men in whom a PSA nadir of less than 0.1 ng/ml on TIP failed to be achieved and maintained and men in whom testosterone failed to recover to greater than 150 ng/dl during the first 12 months of TOP were excluded. Potential factors predicting prolonged TOP or accelerated time to AIPC were studied with Cox regression analysis.

RESULTS

Patient characteristics were clinical stage T1c-T2a in 51 and T2b-T3b in 11, PSA relapse in 29, and T3c, D0 or D1 in 10. Median PSA was 7.6 ng/ml, Gleason score was 3 + 4 = 7 and TIP duration was 15.8 months. The 60 group 1 patients received finasteride and the 41 in group 2 received no finasteride. Median TOP in groups 1 and 2 was 31 and 15 months, respectively, using Kaplan-Meier analysis. Cox regression analysis indicated that longer TIP, finasteride and increased age predicted longer TOP. A slow PSA decrease while on TIP, higher baseline PSA and increased Gleason score predicted shorter TOP. Cox regression analysis indicated that only higher clinical stage but not finasteride predicted the earlier onset of AIPC.

CONCLUSIONS

Finasteride doubles the duration of TOP. AIPC was not increased by finasteride after almost 9 years of observation.

Colonoscopy effects on serum prostate specific antigen levels

INTRODUCTION

To evaluate the colonoscopy effects on serum levels of prostate specific antigen (PSA) and PSA ratio.

SUBJECTS AND METHODS

Thirty men were studied (median age 68 years, range 32-89). All of them had their serum PSA (total and free) measured 24 hours prior to colonoscopy and also 24 hours, 7 and 30 days after procedure.

RESULTS

14 of 30 (47%) patients, had significantly (p = 0.045) increased Total PSA levels 24 hours after the procedure, 14 (47%) patients had insignificantly (p = 0.139) increased levels 7 days after, while 13 (43%) of them had insignificantly (p = 0.061) increased levels 30 days after colonoscopy. In 7 patients (23%), with total PSA levels in the "gray zone" (4-10 ng/ml) before colonoscopy, a near significant (p = 0.063) raise in PSA ratio was also observed 24 hours after.

CONCLUSION

Flexible colonoscopy affect serum PSA (free and total) levels in certain patients. Special attention must be given to those patients with PSA levels in the "gray zone" before colonoscopy.