External validation of a biomarker-based preoperative nomogram predicts biochemical recurrence after radical prostatectomy

PURPOSE

Biomarker signatures currently are used in several malignancies to guide clinical decision making. Recently, preoperative plasma levels of transforming growth factor-beta1 (TGF-beta1) and interleukin-6 soluble receptor (IL6-SR) have improved the accuracy of a clinical nomogram that predicted biochemical recurrence after radical prostatectomy. However, this model was never externally validated. We tested the accuracy of this nomogram in an independent, external cohort.

PATIENTS AND METHODS

Preoperative plasma levels of TGF-beta1 and IL6-SR were measured in 423 consecutive men who underwent radical prostatectomy and bilateral lymphadenectomy and were used, along with preoperative prostate-specific antigen levels, biopsy Gleason sum, and clinical stage to determine nomogram-derived probabilities of biochemical recurrence-free survival at 5 years after radical prostatectomy. The accuracy of predictions was quantified with the area under the curve (AUC) and calibration plots that graphically displayed the nomogram's performance characteristics. The statistical significance of the difference between the biomarker nomogram and a model designed on the basis of clinical variables alone was tested by using the Mantel-Haenszel statistic.

RESULTS

Biochemical recurrence-free survival at 5 years was 77.0% (95% CI, 72.0% to 82.0%). The biomarker-based nomogram was 87.9% accurate versus 71.1% for the nomogram designed on the basis of clinical variables alone (16.8% difference; P < .001). The performance characteristics of the biomarker-based nomogram were superior to those of the clinical nomogram.

CONCLUSION

We confirm that plasma levels of TGF-beta1 and IL6-SR considerably enhance the accuracy of the standard preoperative nomogram for the prediction of biochemical recurrence after radical prostatectomy. This model further refines our ability to identify patients at a high risk of biochemical recurrence after radical prostatectomy.

Blood biomarkers for prostate cancer detection and prognosis

Prostate cancer is the most non-cutaneous malignancy diagnosed in men in the USA. The discovery of prostate-specific antigen (PSA) revolutionized prostate cancer diagnosis and management in the 1990s. Despite its remarkable performance as a marker for prostate cancer, PSA is not prostate cancer specific. PSA can be released by normal as well as hyperplastic prostate cells, which undermines the specificity of PSA for prostate cancer diagnosis. Hence, there is a need for new biomarkers that can detect prostate cancer and, in addition, distinguish indolent from biologically aggressive cancers. Moreover, the emergence of new therapeutic approaches for prostate cancer cannot flourish without a more reliable set of markers to serve as prognosticators, targets and surrogate end points of disease progression and response to treatment. As the most useful clinical biomarkers are likely to be those assayed from blood, there is an increasing interest in profiling blood proteins. With recent advances in biotechnology such as high-throughput molecular analyses, many potential blood biomarkers have been identified and are currently under investigation.

Early postoperative plasma transforming growth factor-beta1 is a strong predictor of biochemical progression after radical prostatectomy

PURPOSE

Blood levels of transforming growth factor-beta1, interleukin-6 and interleukin-6 soluble receptor have been associated with aggressive primary and metastatic prostate cancer. We hypothesized that patients with increased plasma levels of transforming growth factor-beta1, interleukin-6 and/or interleukin-6 soluble receptor after radical prostatectomy would be more likely to harbor occult metastases, leading to disease progression despite effective local control of disease.

MATERIALS AND METHODS

Plasma transforming growth factor-beta1, interleukin-6 and interleukin-6 soluble receptor were measured 6 to 8 weeks after surgery in 291 consecutive patients treated with radical prostatectomy for clinically localized disease. Discrimination and validation of multivariate Cox regression models targeting time to biochemical progression were used to quantify the added value of these markers to predictive accuracy (concordance index) after internal validation with 200 bootstrap resamples.

RESULTS

On multivariate analysis adjusting for standard postoperative features postoperative plasma transforming growth factor-beta1 was the only biomarker independently associated with biochemical progression (p <0.001). The addition of postoperative transforming growth factor-beta1 improved the accuracy of the standard postoperative model from 78.4% to 84.1%, representing a 5.7% gain (p <0.001). Of patients who experienced biochemical progression postoperative transforming growth factor-beta1 was significantly higher in those with features of aggressive disease progression, ie development of metastasis, prostate specific antigen doubling time less than 10 months and/or failure to respond to local salvage radiation therapy (p <0.001).

CONCLUSIONS

Postoperative interleukin-6 and interleukin-6 soluble receptor have limited clinical usefulness in prostate cancer. In contrast, postoperative plasma transforming growth factor-beta1 measured 6 to 8 weeks after surgery is a strong predictor of biochemical progression, presumably due to an association with early low volume occult metastases that are at the threshold of clinical progression.

Alpha1-adrenoceptor subtypes and lower urinary tract symptoms

Benign prostatic hyperplasia (BPH) is a common cause of urinary outflow obstruction in aging men leading to lower urinary tract symptoms (LUTS). alpha(1)-Adrenoceptors (alpha(1)ARs) antagonists (blockers) have become a mainstay of LUTS treatment because they relax prostate smooth muscle and decrease urethral resistance, as well as relieving bladder LUTS symptoms. A review of key recent clinical trials suggests new insights into the role of specific alpha(1)AR subtypes in the treatment of LUTS.

Role of urinary cathepsin B and L in the detection of bladder urothelial cell carcinoma

PURPOSE

We tested the hypothesis that urinary cathepsin B and L are associated with bladder cancer recurrence and invasiveness in patients with a history of nonmuscle invasive urothelial carcinoma of the bladder.

MATERIALS AND METHODS

Cathepsin B and L, and NMP22 were determined in the urine specimens of 188 consecutive subjects with a history of treated urothelial carcinoma of the bladder, 31 with noncancerous urological conditions and 10 healthy subjects. Cathepsin B and L were analyzed as continuous and categorical variables based on their quartile distribution.

RESULTS

Urinary cathepsin L was higher in the 122 patients with cystoscopic evidence of bladder tumor compared with levels in 107 with normal cystoscopy (median 5.9, IQR 4.4 vs 3.0, IQR 3.2, p <0.001). Higher levels of cathepsin L were associated with positive cytology assay results, higher NMP22 and T1 or greater pathological stage (each p <0.001). Area under the ROC curves of NMP22 and cathepsin L for bladder cancer detection were 0.704 (95% CI 0.637-0.772) and 0.793 (95% CI 0.736-0.850), respectively. On multivariate analysis cathepsin L, NMP22 and cytology were associated with invasive pathological stage (OR 1.29, 2.42 and 2.76, respectively, p </=0.002). Urinary cathepsin B was not associated with any outcome variables.

CONCLUSIONS

Urinary cathepsin L is an independent predictor of bladder cancer presence and invasiveness in patients with a history of urothelial carcinoma of the bladder. Further evaluation of this marker is necessary before its use as an adjunct to cystoscopy for urothelial carcinoma of the bladder.

Current medical therapies for men with lower urinary tract symptoms and benign prostatic hyperplasia: achievements and limitations

Over the last 20 years, our understanding of the pathophysiology and symptomatology of men with lower urinary tract symptoms (LUTS) has become increasingly more sophisticated. With this increase in sophistication, our utilization of various medical therapies, either alone or in combination, has also increased the understanding of the roles of individual medications, combinations of medications, and the benefits of different types of intervention. The rapid decline of the use of transurethral resection of the prostate (TURP) and other surgical procedures for benign prostatic hyperplasia (BPH) in the 1990s is due in part to the introduction of medical therapy. This article reviews the current state of medical therapy for men with LUTS and highlights its promises and its current limitations.

Nutraceuticals in Prostate Disease: The Urologist's Role

Interest in and use of complementary and alternative therapies, especially nutraceuticals, is high in prostate disease. These therapies have shown potential in benign prostatic hyperplasia (BPH), prostatitis, and prostate cancer. Some have produced results equal to or better than pharmaceuticals currently prescribed for BPH. In category III prostatitis, some nutraceuticals may offer relief to patients who get little from standard therapy. Because it is becoming apparent that inflammation may play a role in the progression of BPH and development of prostate cancer, nutraceuticals, which commonly have anti-inflammatory properties, may play a role. These therapies have also shown potential in prostate cancer treatment and prevention, especially those that also reduce cardiovascular events or risk. Nevertheless, uses of some nutraceuticals in prostate disease have had less desirable consequences, showing lack of efficacy, adulteration, and/or severe side effects or drug interactions. By ensuring that these therapies undergo careful study for effectiveness, quality, and safety, urologists can look forward to adding them to their evidence-based armamentarium for prostate disease.

Using biopsy to detect prostate cancer

Transrectal ultrasound-guided systemic biopsy is the recommended method in most cases with suspicion of prostate cancer. Transrectal periprostatic injection with a local anesthetic may be offered as effective analgesia; periprostatic nerve block with 1% or 2% lidocaine is the recommended form of pain control. On initial biopsy, a minimum of 10 systemic, laterally directed cores is recommended, with more cores in larger glands. Extended prostate biopsy schemes, which require cores weighted more laterally at the base (lateral horn) and medially to the apex, show better cancer detection rates without increasing adverse events. Transition zone biopsies are not recommended in the first set of biopsies, owing to low detection rates. One set of repeat biopsies is warranted in cases with persistent indication. Saturation biopsy (>/=20 cores) should be reserved for repeat biopsy in patients who have negative results on initial biopsy but who are still strongly suspected to have prostate cancer.

The effects of dutasteride, tamsulosin and combination therapy on lower urinary tract symptoms in men with benign prostatic hyperplasia and prostatic enlargement: 2-year results from the CombAT study

PURPOSE

We investigated whether combination therapy with dutasteride and tamsulosin is more effective than either monotherapy alone for improving symptoms and long-term outcomes in men with moderate to severe lower urinary tract symptoms and prostatic enlargement (30 cc or greater). We report preplanned 2-year analyses.

MATERIALS AND METHODS

The CombAT study is an ongoing, multicenter, randomized, double-blind, parallel group study. Men 50 years or older with a clinical diagnosis of benign prostatic hyperplasia, International Prostate Symptom Score 12 points or greater, prostate volume 30 cc or greater, total serum prostate specific antigen 1.5 ng/ml or greater to 10 ng/ml or less and peak urinary flow greater than 5 to 15 ml per second or less with a minimum voided volume of 125 ml or greater were randomized to 0.5 mg dutasteride, 0.4 mg tamsulosin or the combination once daily for 4 years. Symptoms were assessed every 3 months and peak urinary flow was assessed every 6 months. The primary end point at 2 years was the change in International Prostate Symptom Score from baseline.

RESULTS

Combination therapy resulted in significantly greater improvements in symptoms vs dutasteride from month 3 and tamsulosin from month 9, and in benign prostatic hyperplasia related health status from months 3 and 12, respectively. There was a significantly greater improvement from baseline in peak urinary flow for combination therapy vs dutasteride and tamsulosin monotherapies from month 6. There was a significant increase in drug related adverse events with combination therapy vs monotherapies, although most did not result in the cessation of therapy.

CONCLUSIONS

In men with moderate to severe lower urinary tract symptoms and prostate enlargement (30 cc or greater) combination therapy provides a significantly greater degree of benefit than tamsulosin or dutasteride monotherapy.

The benign prostatic hyperplasia registry and patient survey: study design, methods and patient baseline characteristics

OBJECTIVE

To describe the design and baseline cohort characteristics of the Benign Prostatic Hyperplasia (BPH) Registry and Patient Survey, an ongoing, prospective, observational, disease registry documenting management practices and patient outcomes in men in the USA with lower urinary tract symptoms associated with BPH (LUTS/BPH) in actual clinical practice settings.

PATIENTS AND METHODS

Men with LUTS/BPH who were either untreated or treated with alpha(1)-adrenergic blockers (ABs), 5alpha-reductase inhibitors (5ARIs), a combination of these medications, or anticholinergics, and who met selection criteria, were enrolled at sites throughout the USA. At each visit, standardized forms and validated questionnaires were completed to assess the physicians' management practices and patients' clinical characteristics, sexual function, and health-related quality of life.

RESULTS

At the close of recruitment (February 2005), 6909 men (mean age 66.0 years) were enrolled at 402 sites by urologists and primary-care physicians. Before enrolment, 49% of the men were managed with watchful waiting (WW), 21% with uroselective AB monotherapy, 11% with non-uroselective AB monotherapy, 6% with 5ARI monotherapy, 11% with AB + 5ARI, and 2% with anticholinergics. After enrolment, 42% were on WW and 26% were on selective AB monotherapy; changes in other management groups were minimal. Overall, 33% of the men had mild, 52% had moderate and 15% had severe LUTS. The most common comorbidities were hypertension (53%), high cholesterol (45%) and sexual dysfunction (36%).

CONCLUSION

The BPH Registry and Patient Survey will provide information on physician management practices and outcomes of men with LUTS/BPH, while examining the effects of demographics, socio-economics, comorbidities, and medical therapies.

Combination therapy with dutasteride and tamsulosin in men with moderate-to-severe benign prostatic hyperplasia and prostate enlargement: the CombAT (Combination of Avodart® and Tamsulosin) trial rationale and study design

Benign prostatic hyperplasia (BPH) is a highly prevalent condition in aging men, which can be progressive and lead to acute urinary retention (AUR) and the need for surgery. It is commonly treated with alpha-blockers and 5alpha-reductase inhibitors (5ARIs), both of which improve the symptoms of BPH. Long-term treatment with 5ARIs can also reduce the risk of developing AUR and the need for surgery. The landmark Medical Therapy of Prostatic Symptoms (MTOPS) trial demonstrated that over 4 years the combination of the type 2-specific 5ARI, finasteride and the alpha-blocker doxazosin was more effective than either agent alone in reducing overall clinical progression. Since the initiation of MTOPS, it has been shown that patients with larger prostates and higher prostate-specific antigen (PSA) levels are at greater risk of BPH progression, and are therefore arguably more likely to benefit from combination therapy. The Combination of Avodart and Tamsulosin (CombAT) trial is a 4-year, global, multicenter, randomized, double-blind, parallel-group study designed to investigate the benefits of combination therapy with the dual 5ARI dutasteride and the alpha-blocker tamsulosin compared with each monotherapy in improving symptoms and long-term outcomes in men with moderate-to-severe symptoms of BPH and prostate enlargement. Symptoms and long-term outcomes (AUR and surgery) will be assessed as separate primary endpoints at 2 and 4 years, respectively. Eligible patients were at least 50 years old with prostate volume > or =30 cm(3) and PSA level > or =1.5 ng/mL. A total of 4838 subjects have been enrolled. This paper describes the rationale, design and baseline data of the CombAT study.

Prediction of Pathological Stage is Inaccurate in Men with PSA Values above 20ng/mL

INTRODUCTION

We hypothesized that either very low (0-2.5 ng/mL) or very high (>20 ng/mL) PSA values may limit the accuracy of pathological stage predictions. To test this hypothesis, we examined 5193 consecutive patients subjected to radical prostatectomy (RP) for localized prostate cancer (PCa).

MATERIAL AND METHODS

Patients were divided into three cohorts according to their pre-treatment PSA value: </=2.5 (n=331), 2.51-20 (n=4545) and >20 ng/mL (n=317). Subsequently in each cohort, the ability of PSA, clinical stage and biopsy Gleason sum was tested in multivariable logistic regression models predicting three separate endpoints: extracapsular extension (ECE), seminal vesicle invasion (SVI) and lymph node invasion (LNI). Predictive accuracy represented the performance benchmark. All models were adjusted for year of surgery and subjected to 200 bootstrap resamples to reduce overfit bias.

RESULTS

For PSA </=2.5 ng/mL, predictive accuracy was 76.7%, 72.3% and 82.8% for respectively ECE, SVI and LNI. For PSA 2.51-20 ng/mL, the predictive accuracy for the same endpoints was 67.8%, 77.4% and 81.6%. Finally, for PSA >20 ng/mL, predictive accuracy was 63.6%, 63.7% and 70.6%.

CONCLUSIONS

The ability to predict pathological stage in patients with PSA values in excess of 20 ng/mL significantly decreased, compared to patients with lower PSA values. Therefore, accurate staging of these patients may require alternative markers or staging schemes.

The Effect of Doxazosin, Finasteride and Combination Therapy on Nocturia in Men With Benign Prostatic Hyperplasia

PURPOSE

We evaluated the effectiveness of single or combination drug therapy on nocturia in men with lower urinary tract symptoms suggestive of benign prostatic hyperplasia.

MATERIALS AND METHODS

A total of 3,047 men with lower urinary tract symptoms/benign prostatic hyperplasia enrolled in the Medical Therapy of Prostatic Symptoms trial were randomly assigned to receive doxazosin alone, finasteride alone, combination therapy or placebo. Treatment effectiveness was assessed according to intent to treat by mean reduction in self-reported nightly nocturia at 1 and 4 years. A subgroup analysis by age (younger than 70 vs 70 years old or older) was also performed.

RESULTS

Of the men 2,583 reported 1 or more episodes of nocturia and finished 12 or more months of the trial. Mean nocturia was similar in all groups at baseline. Mean nocturia was reduced at 1 year by 0.35, 0.40, 0.54 and 0.58 in the placebo, finasteride, doxazosin and combination groups, respectively. Reductions with doxazosin and combination therapy were statistically greater than with placebo (p <0.05). At 4 years nocturia was also significantly reduced in patients treated with doxazosin and combination therapy (p <0.05 vs placebo). In men older than 70 years (495) all drugs significantly reduced nocturia at 1 year (finasteride 0.29, doxazosin 0.46 and combination 0.42) compared to placebo (0.11, p <0.05).

CONCLUSIONS

Doxazosin and combination therapy reduced nocturia more than placebo, but the net benefit of active drug compared to placebo was often modest with a net difference of less than 0.20 fewer nightly nocturia episodes at 1 and 4 years. Findings in men 70 years old or older were similar, with an even smaller effect observed for finasteride.

Plasminogen Activation Inhibitor-1 Improves the Predictive Accuracy of Prostate Cancer Nomograms

PURPOSE

We tested whether the addition of preoperative circulating plasminogen activator inhibitor type I levels improves the accuracy of standard preoperative and postoperative models for prediction of biochemical recurrence after radical prostatectomy.

MATERIALS AND METHODS

Preoperative plasma levels of plasminogen activator inhibitor type I were measured in 429 consecutive patients treated with radical prostatectomy for clinically localized prostate cancer. The patients were randomly divided into a development (67%, 286) and a split sample validation cohort (33%, 143). Cox regression analysis was used to develop prognostic nomograms for prediction of biochemical recurrence.

RESULTS

In standard univariate analyses categorically coded preoperative plasminogen activator inhibitor type I was significantly associated with biochemical recurrence (p <0.001). In standard preoperative and postoperative multivariate analyses preoperative plasminogen activator inhibitor type I was independently associated with biochemical recurrence (p <0.001 and p = 0.002, respectively). In the split sample validation cohort the addition of plasminogen activator inhibitor type I increased the predictive accuracy of the preoperative multivariate model by 1.2%, 7.7%, 10.3%, 6.7% and 5.4% at 1, 2, 3, 4 and 5 years, respectively (p values <0.001). Moreover, the addition of plasminogen activator inhibitor type I increased the predictive accuracy of the postoperative model by 0.5%, 1.1%, 4.0%, 2.4% and 3.6% at 1, 2, 3, 4 and 5 years, respectively (p values <0.001).

CONCLUSIONS

Preoperative circulating plasminogen activator inhibitor type I is a predictor of biochemical recurrence, and it enhances the accuracy of preoperative and postoperative nomograms. After external validation these nomograms may assist clinical decision making regarding treatment choice and followup as well as identification of patients at high risk for biochemical recurrence who may benefit from neoadjuvant and/or adjuvant treatment.

Prostate-Specific Antigen Improves the Ability of Clinical Stage and Biopsy Gleason Sum to Predict the Pathologic Stage at Radical Prostatectomy in the New Millennium

OBJECTIVES

The contemporary ability of prostate-specific antigen (PSA) to predict pathologic stage in men with localized prostate cancer was recently questioned.

METHODS

We quantified the added value related to the addition of pretreatment PSA to established pathologic stage predictors (namely clinical stage and biopsy Gleason sum) in 5921 consecutive radical prostatectomy (RP) patients. Univariable and multivariable logistic regression analyses predicting pathologic stage (extracapsular extension [ECE], seminal vesicle invasion [SVI], lymph node invasion [LNI], and organ-confined disease [OC]) were stratified according to four time quartiles. The gain in predictive accuracy (PA) related to the inclusion of PSA to multivariable models was quantified by using the area under the curve method.

RESULTS

Temporal analyses showed a decrease in PSA levels over the study years (p<0.001). Conversely, the rate of nonpalpable disease and the rate of biopsy Gleason sum < or =6 increased over time (all p<0.001). At RP, the rate of OC increased over time, while the rate of ECE and SVI decreased over time (all p<0.001). The rate of LNI remained stable (p=0.1). In multivariable models, PSA represented an independent predictor of all pathologic stages over time (all p<0.03), except for ECE in the first and last time quartiles. The addition of PSA significantly increased the multivariable PA of all models predicting pathologic stages over time (all p<0.03), except for ECE predictions in the first quartile (p=0.1).

CONCLUSIONS

In the new millennium, PSA has not lost its ability to accurately predict the pathologic stage in contemporary patients.

Preoperative Plasma HER2 and Epidermal Growth Factor Receptor for Staging and Prognostication in Patients with Clinically Localized Prostate Cancer

PURPOSE

Human epidermal growth factor receptor-2 (HER2) and epidermal growth factor receptor (EGFR) expression have been associated with disease progression in patients with prostate cancer. We tested the hypothesis that plasma levels of HER2 and/or EGFR are associated with prostate cancer stage and prognosis in patients with clinically localized disease.

EXPERIMENTAL DESIGN

We measured preoperative plasma HER2 and EGFR levels using commercially available ELISAs on banked plasma from 227 patients treated with radical prostatectomy and bilateral lymphadenectomy for clinically localized prostate adenocarcinoma.

RESULTS

Median preoperative plasma EGFR and HER2 levels were 31.4 ng/mL (interquartile range, 19.2 ng/mL) and 10.0 ng/mL (interquartile range, 2.7 ng/mL), respectively. HER2 was elevated in patients with seminal vesicle invasion (P = 0.033). In separate multivariate analyses that adjusted for the effects of standard preoperative predictors, lower EGFR, higher HER2, and higher HER2/EGFR ratio were associated with prostate-specific antigen (PSA) progression (P = 0.003, P < 0.001, and P < 0.001, respectively). In separate multivariate analyses that adjusted for the effects of standard postoperative predictors, lower EGFR and higher HER2/EGFR ratio were associated with PSA progression (P = 0.027 and P < 0.001, respectively). Among the patients who experienced PSA progression, HER2 was significantly higher (P = 0.023) and EGFR was lower (P = 0.04) in those with features of aggressive disease (i.e., development of metastasis, PSA doubling time <10 months, and/or failure to respond to local salvage radiation therapy).

CONCLUSION

Preoperative plasma HER2 and EGFR were associated with prostate cancer progression after radical prostatectomy. Plasma HER2 and EGFR may provide a tool for predicting long-term recurrence-free survival and early metastasis.

Prognostic value of syndecan-1 expression in patients treated with radical prostatectomy

OBJECTIVE

To investigate the association of syndecan-1 expression with pathological features and disease progression in patients treated with radical prostatectomy (RP) as syndecan-1 plays a role in the regulation of cell proliferation, migration, and differentiation and its expression is altered in various malignancies.

PATIENTS AND METHODS

Syndecan-1 immunostaining was performed on a tissue microarray containing cores from 232 consecutive patients treated with RP and bilateral lymphadenectomy for clinically localized prostatic adenocarcinoma. Patients were categorized as having features of aggressive progression if they had evidence of metastases, an after progression prostate-specific antigen (PSA) doubling time of < 10 months, and/or failure to respond to local salvage radiation therapy. Expression was defined as > or = 10% cells staining for syndecan-1.

RESULTS

Syndecan-1 was expressed in 86 patients (37.1%). Expression of syndecan-1 was associated with higher PSA levels (P = 0.004), higher pathological Gleason sum (P = 0.027) and lymph nodes metastases (P = 0.027). Patients with syndecan-1 expression were at significantly greater risk of PSA-progression after surgery (P = 0.034) in univariate but not in multivariate analysis. Patients with features of aggressive progression (n = 22) were more likely to express syndecan-1 than those with features of nonaggressive progression (63.6% vs 36.4%, P = 0.010). Patients with syndecan-1 expression were at significantly greater risk of aggressive progression after surgery (P = 0.005) in univariate but not in multivariate analysis.

CONCLUSIONS

Expression of syndecan-1 was associated with established features of biologically aggressive prostate cancer and PSA-progression in univariate analysis. These findings suggest a role for syndecan-1 in prostate carcinogenesis and progression.