Validation of the partin nomogram for prostate cancer in a national sample

Rational use of Ga-68 PSMA PET-CT according to nomograms and risk groups for the detection of lymph node metastasis in prostate cancer

OBJECTIVES

The aim was to ensure efficient utilization of PSMA PET-CT by examining the correlation of pathological lymph node metastasis with nomogram scores and risk classifications.

METHODS AND MATERIALS

Robot-assisted radical prostatectomy and bilateral pelvic lymph node dissections for pelvic lymph nodes were performed using the same template. Bilaterally pelvic lymph nodes were removed within the boundaries of genitofemoral nerves, psoas muscle and lateral pelvic wall laterally, ureteric crossing of the iliac vessels superiorly, lateral bladder wall medially, Cooper ligaments distally, and endopelvic fascia, neurovascular bundles and internal iliac arteries posteriorly. Clinical nomograms were used to calculate the probability of lymph node metastasis preoperatively. Using receiver operating characteristics analysis, discriminatory cut-offs were calculated. The diagnostic performance of PSMA PET-CT was determined for detecting lymph node metastasis.

RESULTS

For 81 patients, the median age was 64 years. The median PSA was 6.8 ng/ml. Most patients were in the D'Amico intermediate (56.8%) and high (37%) risk groups. Median Briganti 2017, MSKCC, and Partin scores were 35 (4-99), 37 (8-90), and 12 (2-38), respectively, in pN1 patients. The area under the curve for Briganti 2017, MSKCC, Partin nomograms and PSMA PET-CT scans were 0.852, 0.871, 0.862, and 0.588. Sensitivity, specificity, positive predictive value and negative predictive value for Ga-68 PSMA PET-CT for lymph node metastasis detection were 21.4%, 94%, 42.9%, and 85.1%, respectively, for the whole group. By using higher threshold values for clinical nomograms (Briganti 2017 >32, MSKCC >12, Partin >5), PSMA PET-CT had higher sensitivity (42.9, 30, 27.2) in detecting lymph node metastasis.

CONCLUSIONS

Patients in the D'Amico high-risk group and those with high nomogram scores are the best candidates who will benefit from preoperative PSMA PET-CT staging to estimate lymph node metastasis.

Role of Multiparametric Magnetic Resonance Imaging in Predicting Pathologic Outcomes in Prostate Cancer

Multiparametric magnetic resonance imaging (mpMRI) and the introduction of standardized protocols for its interpretation have had a significant impact on the field of prostate cancer (PC). Multiple randomized controlled trials have shown that the sensitivity for detection of clinically significant PC is increased when mpMRI results are the basis for indication of a prostate biopsy. The added value with regards to sensitivity has been strongest for patients with persistent suspicion for PC after a prior negative biopsy. Although enhanced sensitivity of mpMRI is convincing, studies that have compared mpMRI with prostatectomy specimens prepared by whole-mount section analysis have shown a significant number of lesions that were not detected by mpMRI. In this context, the importance of an additional systematic biopsy (SB) is still being debated. While SB in combination with targeted biopsies leads to an increased detection rate, most of the tumors detected by SB only are considered clinically insignificant. Currently, multiple risk calculation tools are being developed that include not only clinical parameters but mpMRI results in addition to clinical parameters in order to improve risk stratification for PC, such as the Partin tables. In summary, mpMRI of the prostate has become a standard procedure recommended by multiple important guidelines for the diagnostic work-up of patients with suspicion of PC.

Integrated predictive model for prostatic cancer using clinical, laboratory and ultrasound data

OBJECTIVE

to develop a predictive model to estimate the probability of prostate cancer prior to biopsy.

METHODS

from September 2009 to January 2014, 445 men underwent prostate biopsy in a radiology service. We excluded from the study patients with diseases that could compromise the data analysis, who had undergone prostatic resection or used 5-alpha-reductase inhibitors. Thus, we selected 412 patients. Variables included in the model were age, prostate specific antigen (PSA), digital rectal examination, prostate volume and abnormal sonographic findings. We constructed Receiver Operating Characteristic (ROC) curves and calculated the areas under the curve, as well as the model's Positive Predictive Value (PPV) .

RESULTS

of the 412 men, 155 (37.62%) had prostate cancer (PC). The mean age was 63.8 years and the median PSA was 7.22ng/ml. In addition, 21.6% and 20.6% of patients had abnormalities on digital rectal examination and image suggestive of cancer by ultrasound, respectively. The median prostate volume and PSA density were 45.15cm3 and 0.15ng/ml/cm3, respectively. Univariate and multivariate analyses showed that only five studied risk factors are predictors of PC in the study (p<0.05). The PSA density was excluded from the model (p=0.314). The area under the ROC curve for PC prediction was 0.86. The PPV was 48.08% for 95%sensitivity and 52.37% for 90% sensitivity.

CONCLUSION

the results indicate that clinical, laboratory and ultrasound data, besides easily obtained, can better stratify the risk of patients undergoing prostate biopsy.

Population-Based External Validation of the Updated 2012 Partin Tables in Contemporary North American Prostate Cancer Patients

OBJECTIVE

To externally validate the updated 2012 Partin Tables in contemporary North American patients treated with radical prostatectomy (RP) for localized prostate cancer (PCa) at community institutions.

MATERIALS AND METHODS

We examined records of 25,254 patients treated with RP and pelvic lymph node dissection (PLND) between 2010 and 2013, within the surveillance, epidemiology, and end results database. The ROC derived AUC assessed discriminant properties of the updated 2012 Partin Tables of organ confined disease (OC), extracapsular extension (ECE), seminal vesical invasion (SVI), and lymph node invasion (LNI). Calibration plots focused on calibration between predicted and observed rates.

RESULTS

Proportions of OC, ECE, SVI, and LNI at RP were 69.8%, 18.4%, 7.4%, and 4.4%, respectively. Accuracy for prediction of OC, ECE, SVI, and LNI was 70.4%, 59.9%, 72.9%, and 77.1%, respectively. In subgroup analyses in patients with nodal yield >10, accuracy for LNI prediction was 76.0%. Subgroup analyses in elderly patients and in African American patients revealed decreased accuracy for prediction of all four endpoints. Last but not least, SVI and LNI calibration plots showed excellent agreement, versus good agreement for OC (maximum underestimation of 10%) and poor agreement for ECE (maximum overestimation of 12%).

CONCLUSION

Taken together, the updated 2012 Partin Tables can be unequivocally endorsed for prediction of OC, SVI, and LNI in community-based patients with localized PCa. Conversely, ECE predictions failed to reach the minimum accuracy requirements of 70%. Prostate 77:105-113, 2017. © 2016 Wiley Periodicals, Inc.

Prediction of pathological stage based on clinical stage, serum prostate-specific antigen, and biopsy Gleason score: Partin Tables in the contemporary era

OBJECTIVE

To update the Partin Tables for prediction of pathological stage in the contemporary setting and examine trends in patients treated with radical prostatectomy (RP) over the past three decades.

PATIENTS AND METHODS

From January 2010 to October 2015, 4459 men meeting inclusion criteria underwent RP and pelvic lymphadenectomy for histologically confirmed prostate cancer at the Johns Hopkins Hospital. Preoperative clinical stage, serum prostate-specific antigen (PSA) level, and biopsy Gleason score (i.e. prognostic Grade Group) were used in a polychotomous logistic regression model to predict the probability of pathological outcomes categorised as: organ-confined (OC), extraprostatic extension (EPE), seminal vesicle involvement (SV+), or lymph node involvement (LN+). Preoperative characteristics and pathological findings in men treated with RP since 1983 were collected and clinical-pathological trends were described.

RESULTS

The median (range) age at surgery was 60 (34-77) years and the median (range) PSA level was 4.9 (0.1-125.0) ng/mL. The observed probabilities of pathological outcomes were: OC disease in 74%, EPE in 20%, SV+ in 4%, and LN+ in 2%. The probability of EPE increased substantially when biopsy Gleason score increased from 6 (Grade Group 1, GG1) to 3 + 4 (GG2), with smaller increases for higher grades. The probability of LN+ was substantially higher for biopsy Gleason score 9-10 (GG5) as compared to lower Gleason scores. Area under the receiver operating characteristic curves for binary logistic models predicting EPE, SV+, and LN+ vs OC were 0.724, 0.856, and 0.918, respectively. The proportion of men treated with biopsy Gleason score ≤6 cancer (GG1) was 47%, representing a substantial decrease from 63% in the previous cohort and 77% in 2000-2005. The proportion of men with OC cancer has remained similar during that time, equalling 73-74% overall. The proportions of men with SV+ (4.1% from 3.4%) and LN+ (2.3% from 1.4%) increased relative to the preceding era for the first time since the Partin Tables were introduced in 1993.

CONCLUSIONS

The Partin Tables remain a straightforward and accurate approach for projecting pathological outcomes based on readily available clinical data. Acknowledging these data are derived from a tertiary care referral centre, the proportion of men with OC disease has remained stable since 2000, despite a substantial decline in the proportion of men with biopsy Gleason score 6 (GG1). This is consistent with the notion that many men with Gleason score 6 (GG1) disease were over treated in previous eras.

Risk stratification of prostate cancer: integrating multiparametric MRI, nomograms and biomarkers

Accurate risk stratification of prostate cancer is achieved with a number of existing tools to ensure the identification of at-risk patients, characterization of disease aggressiveness, prediction of cancer burden and extrapolation of treatment outcomes for appropriate management of the disease. Statistical tables and nomograms using classic clinicopathological variables have long been the standard of care. However, the introduction of multiparametric MRI, along with fusion-guided targeted prostate biopsy and novel biomarkers, are being assimilated into clinical practice. The majority of studies to date present the outcomes of each in isolation. The current review offers a critical and objective assessment regarding the integration of multiparametric MRI and fusion-guided prostate biopsy with novel biomarkers and predictive nomograms in contemporary clinical practice.

Extended lymph node dissection in robotic radical prostatectomy: Current status

Introduction:

The role and extent of extended pelvic lymph node dissection (ePLND) during radical prostatectomy (RP) for prostate cancer patients remains unclear.

Materials and Methods:

A PubMed literature search was performed for studies reporting on treatment regimens and outcomes in patients with prostate cancer treated by RP and extended lymph node dissection between 1999 and 2013.

Results:

Studies have shown that RP can improve progression-free and overall survival in patients with lymph node-positive prostate cancer. While this finding requires further validation, it does allow urologists to question the former treatment paradigm of aborting surgery when lymph node invasion from prostate cancer occurred, especially in patients with limited lymph node tumor infiltration. Studies show that intermediate- and high-risk patients should undergo ePLND up to the common iliac arteries in order to improve nodal staging.

Conclusions:

Evidence from the literature suggests that RP with ePLND improves survival in lymph node-positive prostate cancer. While studies have shown promising results, further improvements and understanding of the surgical technique and post-operative treatment are required to improve treatment for prostate cancer patients with lymph node involvement.

ERG rearrangement as a novel marker for predicting the extra-prostatic extension of clinically localised prostate cancer

Currently, there are no well-established preoperative clinicopathological parameters for predicting extra-prostatic extension (EPE) in patients with clinically localised prostate cancer (PCa). The transmembrane protease serine 2 (TMPRSS2)-ETS-related gene (ERG) fusion gene is a specific biomarker of PCa and is considered a prognostic predictor. The aim of the present study was to assess the value of this marker for predicting EPE in patients with clinically localised PCa. In total, 306 PCa patients with clinically localised disease, including 220 patients (71.9%) with organ-confined disease and 86 EPE cases (28.1%), were included in the study. Receiver operating characteristic curves and logistic regression were employed to establish the optimal cut-off value and to investigate whether ERG rearrangement was an independent predictor for the EPE of clinically localised PCa. A leave-one-out cross-validation (LOOCV) model was implemented to validate the predictive power of ERG rearrangement. An increase in ERG rearrangements was identified to be associate'd with EPE, and the optimal cut-off for predicting EPE was determined to be 2.25%, with a sensitivity of 70.24% [95% confidence interval (CI), 62.6-78.9%], a specificity of 80.43% (95% CI, 75.4-85.1%), and an area under the curve (AUC) of 0.781 (95% CI, 0.730-0.826). In the LOOCV model, ERG rearrangement also demonstrated good performance for predicting EPE (sensitivity, 76.923%; specificity, 71.429%; 95% CI for AUC, 0.724-0.958). In addition, a high Gleason score (≥7) and a cT2c classification upon biopsy were independent factors for EPE.

External validation of a Brazilian predictive nomogram for pathologic outcomes following radical prostatectomy in tertiary teaching institutions: the USP nomograms

PURPOSES

(a) To externally validate the Crippa and colleagues' nomograms combining PSA, percentage of positive biopsy cores (PPBC) and biopsy Gleason score to predict organ-confined disease (OCD) in a contemporary sample of patients treated at a tertiary teaching institution. (b) To adjust such variables, resulting in predictive nomograms for OCD and seminal vesicle invasion (SVI): the USP nomograms.

MATERIALS AND METHODS

The accuracy of Crippa and colleagues' nomograms for OCD prediction was examined in 1002 men submitted to radical prostatectomy between 2005 and 2010 at the University of São Paulo (USP). ROC-derived area under the curve (AUC) and Brier scores were used to assess the discriminant properties of nomograms for OCD. Nomograms performance was explored graphically with LOESS smoothing plots. Furthermore, univariate analysis and logistic regression models targeted OCD and SVI. Variables consisted of PSA, PPBC, biopsy Gleason score and clinical stage. The resulted predictive nomograms for OCD and SVI were internally validated with bootstrapping and the same abovementioned procedures.

RESULTS

Crippa and colleagues' nomograms for OCD showed ROC AUC = 0.68 (CI: 0.65-0.70), Brier score = 0.17 and overestimation in LOESS plots. USP nomograms for OCDand SVI showed ROC AUC of 0.73 (CI: 0.70-0.76) and 0.77 (CI: 0.73-0.79), respectively, and Brier scores of 0.16 and 0.08, respectively. The LOESS plots showed excellent calibration for OCD and underestimation for SVI.

CONCLUSIONS

Crippa and colleagues' nomograms showed moderate discrimination and considerable OCD overestimation. USP nomograms showed good discrimination for OCD and SVI, as well as excellent calibration for OCD and SVI underestimation.

External validation of risk classification in patients with docetaxel-treated castration-resistant prostate cancer

BACKGROUND

Castration-resistant prostate cancer (CRPC) patients have poor prognoses, and docetaxel (DTX) is among the few treatment options. An accurate risk classification to identify CRPC patient groups for which DTX would be effective is urgently warranted. The Armstrong risk classification (ARC), which classifies CRPC patients into 3 groups, is superior; however, its usefulness remains unclear, and further external validation is required before clinical use. This study aimed to examine the clinical significance of the ARC through external validation in DTX-treated Japanese CRPC patients.

METHODS

CRPC patients who received 2 or more DTX cycles were selected for this study. Patients were classified into good-, intermediate-, and poor-risk groups according to the ARC. Prostate-specific antigen (PSA) responses and overall survival (OS) were calculated and compared between the risk groups. A multivariate analysis was performed to clarify the relationship between the ARC and major patient characteristics.

RESULTS

Seventy-eight CRPC patients met the inclusion criteria. Median PSA levels at DTX initiation was 20 ng/mL. Good-, intermediate-, and poor-risk groups comprised 51 (65%), 17 (22%), and 10 (13%) patients, respectively. PSA response rates ≥ 30% and ≥ 50% were 33%, 41%, and 30%, and 18%, 41%, and 20% in the good-, intermediate-, and poor-risk groups, respectivcixely, with no significant differences (p = 0.133 and 0.797, respectively). The median OS in the good-, intermediate-, and poor-risk groups were statistically significant (p < 0.001) at 30.1, 14.2, and 5.7 months, respectively. A multivariate analysis revealed that the ARC and PSA doubling time were independent prognostic factors.

CONCLUSIONS

Most of CRPC patients were classified into good-risk group according to the ARC and the ARC could predict prognosis in DTX-treated CRPC patients.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR) number, UMIN000011969.

Evaluation of prediction models for the staging of prostate cancer

Background

There are dilemmas associated with the diagnosis and prognosis of prostate cancer which has lead to over diagnosis and over treatment. Prediction tools have been developed to assist the treatment of the disease.

Methods

A retrospective review was performed of the Irish Prostate Cancer Research Consortium database and 603 patients were used in the study. Statistical models based on routinely used clinical variables were built using logistic regression, random forests and k nearest neighbours to predict prostate cancer stage. The predictive ability of the models was examined using discrimination metrics, calibration curves and clinical relevance, explored using decision curve analysis. The N = 603 patients were then applied to the 2007 Partin table to compare the predictions from the current gold standard in staging prediction to the models developed in this study.

Results

30% of the study cohort had non organ-confined disease. The model built using logistic regression illustrated the highest discrimination metrics (AUC = 0.622, Sens = 0.647, Spec = 0.601), best calibration and the most clinical relevance based on decision curve analysis. This model also achieved higher discrimination than the 2007 Partin table (ECE AUC = 0.572 & 0.509 for T1c and T2a respectively). However, even the best statistical model does not accurately predict prostate cancer stage.

Conclusions

This study has illustrated the inability of the current clinical variables and the 2007 Partin table to accurately predict prostate cancer stage. New biomarker features are urgently required to address the problem clinician’s face in identifying the most appropriate treatment for their patients. This paper also demonstrated a concise methodological approach to evaluate novel features or prediction models.

ACR Appropriateness Criteria prostate cancer--pretreatment detection, staging, and surveillance

Prostate cancer is the most common noncutaneous male malignancy in the United States. The use of serum prostate-specific antigen as a screening tool is complicated by a significant fraction of nonlethal cancers diagnosed by biopsy. Ultrasound is used predominately as a biopsy guidance tool. Combined rectal examination, prostate-specific antigen testing, and histology from ultrasound-guided biopsy provide risk stratification for locally advanced and metastatic disease. Imaging in low-risk patients is unlikely to guide management for patients electing up-front treatment. MRI, CT, and bone scans are appropriate in intermediate-risk to high-risk patients to better assess the extent of disease, guide therapy decisions, and predict outcomes. MRI (particularly with an endorectal coil and multiparametric functional imaging) provides the best imaging for cancer detection and staging. There may be a role for prostate MRI in the context of active surveillance for low-risk patients and in cancer detection for undiagnosed clinically suspected cancer after negative biopsy results. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every 2 years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer-reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances in which evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

Prostate cancer cell phenotypes based on AGR2 and CD10 expression

The combination of expression patterns of AGR2 (anterior gradient 2) and CD10 by prostate cancer provided four phenotypes that correlated with clinical outcome. Based on immunophenotyping, CD10(low)AGR2(high), CD10(high)AGR2(high), CD10(low)AGR2(low), and CD10(high)AGR2(low) were distinguished. AGR2(+) tumors were associated with longer recurrence-free survival and CD10(+) tumors with shorter recurrence-free survival. In high-stage cases, the CD10(low)AGR2(high) phenotype was associated with a ninefold higher recurrence-free survival than the CD10(high)AGR2(low) phenotype. The CD10(high)AGR2(high) and CD10(low)AGR2(low) phenotypes were intermediate. The CD10(high)AGR2(low) phenotype was most frequent in high-grade primary tumors. Conversely, bone and other soft tissue metastases, and derivative xenografts, expressed more AGR2 and less CD10. AGR2 protein was readily detected in tumor metastases. The CD10(high)AGR2(low) phenotype in primary tumors is predictive of poor outcome; however, the CD10(low)AGR2(high) phenotype is more common in metastases. It appears that AGR2 has a protective function in primary tumors but may have a role in the distal spread of tumor cells.

The identification and internal validation of a preoperative serum biomarker panel to determine extracapsular extension in patients with prostate cancer

BACKGROUND

Accurate preoperative staging of prostate cancer (PCa) is important but current diagnostic methods cannot accurately determine extracapsular extension (ECE), resulting in the possible triage of patients towards a less appropriate arm of therapy. This has consequences to patient care and better methods of preoperatively determining ECE are required.

METHODS

We followed a biomarker development pathway and compared the preoperative serum expressions of VEGF-D, PEDF, IGF-I, IGFBP3, and CD14 in patients from the Irish Prostate Cancer Research Consortium (PCRC) with radical prostatectomy determined ECE against patients with nonECE.

RESULTS

The expression measurements of five proteins were fitted into a logistic regression model and backwards variable elimination methods were applied which resulted in a model with IGFBP3 and CD14 as the best combination biomarker panel. This panel was tested in an independent cohort of patients using an optimized multiplex electrochemiluminescence assay. Receiver operating characteristic curves were generated and the areas under the curve (AUC) were calculated as an estimation of prediction accuracy. The biomarker panel was validated with an AUC of 76.6%, and a sensitivity and specificity of 80% and 75% was obtained.

CONCLUSIONS

This is the first internally validated, preoperative serum biomarker panel that identifies ECE in patients with Gleason score 7 PCa with AUC 76.6%. The panel surpasses the routinely used diagnostic standards in accuracy and may help to improve preoperative cancer staging, better inform treatment options, and improve the referral patterns of patients with urgently treatable cancers towards more appropriate arms of therapy.

An updated prostate cancer staging nomogram (Partin tables) based on cases from 2006 to 2011

OBJECTIVE

To update the 2007 Partin tables in a contemporary patient population.

PATIENTS AND METHODS

The study population consisted of 5,629 consecutive men who underwent RP and staging lymphadenectomy at the Johns Hopkins Hospital between January 1, 2006 and July 30, 2011 and met inclusion criteria. Polychotomous logistic regression analysis was used to predict the probability of each pathologic stage category: organ-confined disease (OC), extraprostatic extension (EPE), seminal vesicle involvement (SV+), or lymph node involvement (LN+) based on preoperative criteria. Preoperative variables included biopsy Gleason score (6, 3+4, 4+3, 8, and 9-10), serum PSA (0-2.5, 2.6-4.0, 4.1-6.0, 6.1-10.0, greater than 10.0 ng/mL), and clinical stage (T1c, T2c, and T2b/T2c). Bootstrap re-sampling with 1000 replications was performed to estimate 95% confidence intervals for predicted probabilities of each pathologic state.

RESULTS

The median PSA was 4.9 ng/mL, 63% had Gleason 6 disease, and 78% of men had T1c disease. 73% of patients had OC disease, 23% had EPE, 3% had SV+ but not LN+, and 1% had LN+ disease. Compared to the previous Partin nomogram, there was no change in the distribution of pathologic state. The risk of LN+ disease was significantly higher for tumours with biopsy Gleason 9-10 than Gleason 8 (O.R. 3.2, 95% CI 1.3-7.6). The c-indexes for EPE vs. OC, SV+ vs. OC, and LN+ vs. OC were 0.702, 0.853, and 0.917, respectively. Men with biopsy Gleason 4+3 and Gleason 8 had similar predicted probabilities for all pathologic stages. Most men presenting with Gleason 6 disease or Gleason 3+4 disease have <2% risk of harboring LN+ disease and may have lymphadenectomy omitted at RP.

CONCLUSIONS

The distribution of pathologic stages did not change at our institution between 2000-2005 and 2006-2011. The updated Partin nomogram takes into account the updated Gleason scoring system and may be more accurate for contemporary patients diagnosed with prostate cancer.

Biomarker research in prostate cancer--towards utility, not futility

The identification of an appropriate clinical question is critical for any biomarker project. Despite rapid advances in technology, few biomarkers have been forthcoming for prostate cancer. This could be because the clinical questions under investigation have not actually originated from clinical practice. These clinical questions are difficult to identify in the complex and heterogeneous pathogenesis of prostate cancer. In this Review, we have developed a prostate cancer 'roadmap' to identify the aspects of prostate cancer that may be amenable to biomarker discovery and serve as a guide for future projects in prostate cancer biomarker research.

Head-to-head comparison of three commonly used preoperative tools for prediction of lymph node invasion at radical prostatectomy

OBJECTIVE

A formal validation and head-to-head comparison of the National Comprehensive Cancer Network (NCCN) practice guideline lymph node invasion (LNI) nomogram, Partin tables, and D'Amico risk-classification was conducted for prediction of LNI at radical prostatectomy (RP).

METHODS

We focused on 20,877 patients treated with RP and pelvic lymph node dissection (PLND) between 2004 and 2006 within the Surveillance, Epidemiology and End Results database. The discrimination of the 3 tools in predicting histologically confirmed LNI was quantified using the area under the curve (AUC). Calibration plots were used to graphically depict the performance characteristics of the examined tools. In addition, we relied on decision curve analyses to compare the 3 models directly in a head-to-head fashion.

RESULTS

Overall, 2.5% of patients had LNI. The NCCN LNI nomogram (AUC 82%) outperformed the Partin tables (73%) and the D'Amico risk-classification (75%) for prediction of LNI. Calibration plots revealed that all 3 tools overestimated the risk of LNI. Partin tables showed the highest net-benefit for probability threshold range between 1% and 4%. Conversely, the NCCN LNI nomogram showed the highest net-benefit for the remaining threshold probabilities.

CONCLUSION

The NCCN LNI nomogram had the highest discrimination accuracy. However, using the decision curve analysis, the Partin tables demonstrated the highest net benefit when a threshold probability of LNI is <4%. In contrast, the NCCN LNI nomogram had the highest net benefit when the threshold probability used to perform PLND is greater than 4%.

Is primary prostate cancer treatment influenced by likelihood of extraprostatic disease? A surveillance, epidemiology and end results patterns of care study

PURPOSE

To examine the patterns of primary treatment in a recent population-based cohort of prostate cancer patients, stratified by the likelihood of extraprostatic cancer as predicted by disease characteristics available at diagnosis.

METHODS AND MATERIALS

A total of 157,371 patients diagnosed from 2004 to 2008 with clinically localized and potentially curable (node-negative, nonmetastatic) prostate cancer, who have complete information on prostate-specific antigen, Gleason score, and clinical stage, were included. Patients with clinical T1/T2 disease were grouped into categories of <25%, 25%-50%, and >50% likelihood of having extraprostatic disease using the Partin nomogram. Clinical T3/T4 patients were examined separately as the highest-risk group. Logistic regression was used to examine the association between patient group and receipt of each primary treatment, adjusting for age, race, year of diagnosis, marital status, Surveillance, Epidemiology and End Results database region, and county-level education. Separate models were constructed for primary surgery, external-beam radiotherapy (RT), and conservative management.

RESULTS

On multivariable analysis, increasing likelihood of extraprostatic disease was significantly associated with increasing use of RT and decreased conservative management. Use of surgery also increased. Patients with >50% likelihood of extraprostatic cancer had almost twice the odds of receiving prostatectomy as those with <25% likelihood, and T3-T4 patients had 18% higher odds. Prostatectomy use increased in recent years. Patients aged 76-80 years were likely to be managed conservatively, even those with a >50% likelihood of extraprostatic cancer (34%) and clinical T3-T4 disease (24%). The proportion of patients who received prostatectomy or conservative management was approximately 50% or slightly higher in all groups.

CONCLUSIONS

There may be underutilization of RT in older prostate cancer patients and those with likely extraprostatic disease. Because more than half of prostate cancer patients do not consult with a radiation oncologist, a multidisciplinary consultation may affect the treatment decision-making process.

Prostate cancers detected by saturation repeat biopsy impairs the Partin tables' accuracy to predict final pathological stage

OBJECTIVE

• To analyse the overall accuracy of Partin tables, with special emphasis to potential limitations resulting from differences between prostate cancers detected by different biopsy schedules.

PATIENTS AND METHODS

• Clinical characteristics from 599 patients treated with radical prostatectomy defined the 2007 Partin probabilities of organ confinement (OC), seminal vesicle invasion (SVI) and extracapsular extension (ECE). Prostate cancers were detected by initial biopsy (IBx) with ≤12 cores in 405 patients (67.6%), by conventional repeat biopsy (CRBx) with ≤12 cores in 99 (16.5%) and by saturation repeat biopsy (SRBx) with ≥20 cores in 95 patients (15.9%). • The area under the curve (AUC) estimated by the receiver operating characteristic curve, assessed the predictive accuracy of the 2007 Partin tables.

RESULTS

• The Partin tables AUC of the IBx, CRBx and the SRBx groups were 0.730 vs 0.701 vs 0.585 for OC, 0.631 vs 0.689 vs 0.547 for ECE, and 0.775 vs 0.755 vs 0.641 for SVI, respectively.

CONCLUSIONS

• The overall accuracy of the 2007 Partin tables was clearly inferior in patients with prostate cancers detected by SRBx. • Prostate cancers detected by SRBx undermine the Partin tables' overall accuracy, and this group of patients may be miscounselled by vague predictions.

A population-based assessment of the National Comprehensive Cancer Network practice guideline indications for pelvic lymph node dissection at radical prostatectomy

OBJECTIVES

To examine the ability of the threshold recommended by the National Comprehensive Cancer Network (NCCN) in correctly predicting histologically-confirmed lymph node invasion (LNI). The 2010 NCCN practice guidelines for prostate cancer recommend a pelvic lymph node dissection (PLND) at radical prostatectomy in all individuals with a nomogram predicted LNI risk of ≥2%.

PATIENTS AND METHODS

We assessed 20,877 patients who were treated with radical prostatectomy and PLND between 2004 and 2006, within the Surveillance, Epidemiology and End Results database. The 2% nomogram threshold, as well as other threshold values (range 1-10%) were tested. Finally, we externally validated the NCCN guideline nomogram.

RESULTS

Overall, 2.5% of patients had LNI. The use of the 2% threshold would allow the avoidance of 23% of PLNDs, at the cost of missing 1.7% of patients with LNI. Conversely, the use of a 3% threshold would allow the avoidance of 58% of PLNDs, at the cost of missing 15% of patients with LNI vs 72% and 26%, respectively, for the 4% threshold. Overall, the accuracy of the NCCN guideline nomogram quantified according to the receiver-operator characteristics-derived area under the curve was 82%.

CONCLUSIONS

In a population-based sample, the NCCN guideline nomogram is highly accurate. However, the 2% threshold will permit the avoidance of only 23% of PLNDs, instead of the 48% intended by the NCCN guidelines. The use of a 3% threshold may allow a lower rate of PLND overtreatment, although it will miss more patients with LNI.

Development and validation of a reference table for prediction of postoperative mortality rate in patients treated with radical cystectomy: a population-based study

PURPOSE

The existing literature suggests that the postoperative mortality (POM) rate in radical cystectomy (RC) patients does not exceed 3%. We sought to develop and externally validate a reference table that quantifies POM after RC.

METHODS

We identified 12,274 patients treated with RC, between 1998 and 2007, within the Nationwide Inpatient Sample database. A total of 6188 (50.4%) randomly selected patients was used as the development cohort. Logistic regression analysis for prediction of POM adjusted for: age, sex, race, Charlson comorbidity index (CCI), urinary diversion type, year of surgery, annual hospital caseload, location/teaching status of hospital, region and bed size of hospital. The reference table was developed by using stepwise variable removal to identify the most accurate and parsimonious model. The model was externally validated in 6086 (49.6%) patients.

RESULTS

POM occurred in 2.4% of patients. POM proportion increased with increasing age (≤59: 0.6% vs. 60-69: 1.6% vs. 70-79: 3.1% vs. ≥80: 4.6%, P < 0.001), and higher CCI (CCI 0: 1.7% vs. CCI 1: 3.0% vs. CCI 2: 4.2% vs. CCI 3: 4.3% vs. CCI ≥ 4: 12.1%, P < 0.001). In multivariable analyses, only age and CCI remained as independent predictors of POM, after stepwise variable removal. The discrimination accuracy of the reference table in predicting POM was 70%.

CONCLUSIONS

Age and CCI represent the foremost determinants of POM after RC. The developed reference table is capable of predicting POM after RC, in an individualized fashion. The accuracy of the model is good (70%), and it is highly generalizable.

Temporal trends and predictors of pelvic lymph node dissection in open or minimally invasive radical prostatectomy

BACKGROUND

Pelvic lymph node dissection (PLND) is an important component of prostate cancer staging and treatment, especially for surgical patients who have high-risk tumor features. It is not clear how the shift from open radical prostatectomy (ORP) to minimally invasive radical prostatectomy (MIRP) has affected the use of PLND. The objectives of this study were to identify predictors of PLND and to assess the impact of surgical technique in a contemporary, population-based cohort.

METHODS

In Surveillance, Epidemiology, and End Results (SEER) cancer registry data linked with Medicare claims, the authors identified men who underwent ORP or MIRP for prostate cancer during 2003 to 2007. The impact of surgical approach on PLND was evaluated, and interactions were examined between surgical procedure, prostate-specific antigen (PSA), and Gleason score with the analysis controlled for patient and tumor characteristics.

RESULTS

Of 6608 men who underwent ORP or MIRP, 70% (n = 4600) underwent PLND. The use of PLND declined over time both overall and within subgroups defined by procedure type. PLND was 5 times more likely in men who underwent ORP than in men who underwent MIRP when the analysis was controlled for patient and tumor characteristics. Elevated PSA and biopsy Gleason score, but not clinical stage, were associated with a greater odds of PLND in both the ORP group and the MIRP group. However, the magnitude of the association between these factors and PLND was significantly greater for patients in the ORP group.

CONCLUSIONS

PLND was less common among men who underwent MIRP, independent of tumor risk factors. A decline in PLND rates was not fully explained by an increase in MIRP. The authors concluded that these trends may signal a surgical approach-dependent disparity in prostate cancer staging and therapy.

Predictive and prognostic models in radical prostatectomy candidates: a critical analysis of the literature

CONTEXT

Numerous predictive and prognostic tools have recently been developed for risk stratification of prostate cancer (PCa) patients who are candidates for or have been treated with radical prostatectomy (RP).

OBJECTIVE

To critically review the currently available predictive and prognostic tools for RP patients and to describe the criteria that should be applied in selecting the most accurate and appropriate tool for a given clinical scenario.

EVIDENCE ACQUISITION

A review of the literature was performed using the Medline, Scopus, and Web of Science databases. Relevant reports published between 1996 and January 2010 identified using the keywords prostate cancer, radical prostatectomy, predictive tools, predictive models, and nomograms were critically reviewed and summarised.

EVIDENCE SYNTHESIS

We identified 16 predictive and 22 prognostic validated tools that address a variety of end points related to RP. The majority of tools are prediction models, while a few consist of risk-stratification schemes. Regardless of their format, the tools can be distinguished as preoperative or postoperative. Preoperative tools focus on either predicting pathologic tumour characteristics or assessing the probability of biochemical recurrence (BCR) after RP. Postoperative tools focus on cancer control outcomes (BCR, metastatic progression, PCa-specific mortality [PCSM], overall mortality). Finally, a novel category of tools focuses on functional outcomes. Prediction tools have shown better performance in outcome prediction than the opinions of expert clinicians. The use of these tools in clinical decision-making provides more accurate and highly reproducible estimates of the outcome of interest. Efforts are still needed to improve the available tools' accuracy and to provide more evidence to further justify their routine use in clinical practice. In addition, prediction tools should be externally validated in independent cohorts before they are applied to different patient populations.

CONCLUSIONS

Predictive and prognostic tools represent valuable aids that are meant to consistently and accurately provide most evidence-based estimates of the end points of interest. More accurate, flexible, and easily accessible tools are needed to simplify the practical task of prediction.

Decision curve analysis to compare 3 versions of Partin Tables to predict final pathologic stage

OBJECTIVE

To perform a decision curve analysis (DCA) to compare the Partin Tables 1997, 2001, and 2007 for their clinical applicability.

MATERIAL AND METHODS

Clinical and pathologic data of 687 consecutive patients treated with open radical prostatectomy for clinically localized prostate cancer between 2003 and 2008 at a single institution were used. DCA quantified the net benefit relating to specific threshold probabilities of extraprostatic extension (EPE), seminal vesicle involvement (SVI), and lymph node involvement (LNI).

RESULTS

Overall, EPE, SVI, and LNI were recorded in 17.8, 6.0, and 1.2%, respectively. For EPE predictions, the DCA favored the 2007 version vs. 1997 for SVI vs. none of the versions for LNI.

CONCLUSIONS

DCA indicate that for very low prevalence conditions such as LNI (1.2%), decision models are not useful. For low prevalence rates such as SVI, the use of different versions of the Partin Tables does not translate into meaningful net gains differences. Finally, for intermediate prevalence conditions such as EPE (18%), despite apparent performance differences, the net benefit differences were also marginal. In consequence, the current analysis could not confirm an important benefit from the use of the Partin Tables and it could not identify a clearly better version of any of the 3 available iterations.

Prediction of patient-specific risk and percentile cohort risk of pathological stage outcome using continuous prostate-specific antigen measurement, clinical stage and biopsy Gleason score

OBJECTIVES

• To develop a '2010 Partin Nomogram' with total prostate-specific antigen (tPSA) as a continuous biomarker, in light of the fact that the current 2007 Partin Tables restrict the application of tPSA as a non-continuous biomarker by creating 'groups' for risk stratification with tPSA levels (ng/mL) of 0-2.5, 2.6-4.0, 4.1-6.0, 6.1-10.0 and >10.0. • To use a 'predictiveness curve' to calculate the percentile risk of a patient among the cohort.

PATIENTS AND METHODS

• In all, 5730 and 1646 patients were treated with radical prostatectomy (without neoadjuvant therapy) between 2000 and 2005 at the Johns Hopkins Hospital (JHH) and University Clinic Hamburg-Eppendorf (UCHE), respectively. • Multinomial logistic regression analysis was performed to create a model for predicting the risk of the four non-ordered pathological stages, i.e. organ-confined disease (OC), extraprostatic extension (EPE), and seminal vesicle (SV+) and lymph node (LN+) involvement. • Patient-specific risk was modelled as a function of the B-spline basis of tPSA (with knots at the first, second and third quartiles), clinical stage (T1c, T2a, and T2b/T2c) and biopsy Gleason score (5-6, 3 + 4 = 7, 4 + 3 = 7, 8-10).

RESULTS

• The '2010 Partin Nomogram' calculates patient-specific absolute risk for all four pathological outcomes (OC, EPE, SV+, LN+) given a patient's preoperative clinical stage, tPSA and biopsy Gleason score. • While having similar performance in terms of calibration and discriminatory power, this new model provides a more accurate prediction of patients' pathological stage than the 2007 Partin Tables model. • The use of 'predictiveness curves' has also made it possible to obtain the percentile risk of a patient among the cohort and to gauge the impact of risk thresholds for making decisions regarding radical prostatectomy.

CONCLUSION

• The '2010 Partin Nomogram' using tPSA as a continuous biomarker together with the corresponding 'predictiveness curve' will help clinicians and patients to make improved treatment decisions.

Head to head comparison of three generations of Partin tables to predict final pathological stage in clinically localised prostate cancer

OBJECTIVE

To perform a head to head comparison between three generations of Partin tables, namely from 1997, 2001 and the last updated version of 2007.

MATERIAL AND METHODS

The external validations were based on clinical and pathological data of 687 consecutive patients undergoing radical prostatectomy for clinically localised prostate cancer between 2003 and 2008. Three versions of the Partin tables were compared for their accuracy and performance to predict final pathological stage using receiver operating characteristic (ROC) curve and Loess plots analyses.

RESULTS

Of the whole cohort, 76.2% of men were presented with organ-confined disease (OC), 17.0% had extraprostatic extension (ECE), 6.0% showed seminal vesicle involvement (SVI) and 1.2% had lymph node involvement (LNI). The area under the receiver operating characteristic curve (AUC) of the Partin Tables 1997, 2001 and 2007 was 0.731, 0.727 and 0.722 for OC; 0.671, 0.662 and 0.650 for ECE; 0.795, 0.788 and 0.779 for SVI as well as 0.826, 0.786 and 0.746 for LNI, respectively.

CONCLUSION

All three generations of the Partin tables showed a good accuracy to predict OC, SVI and LNI. However, the predictive accuracy for ECE was only modest. Overall, the newer versions of the Partin tables could not exceed the version of 1997 in their predictive accuracy for any pathological stage and they failed to demonstrate a clear advantage. Our results underline the necessity to perform external validations before the implementation of a new predicting tool.

Treatment of localized prostate cancer: when is active surveillance appropriate?

Testing for prostate-specific antigen (PSA) has caused a dramatic increase in the incidence of prostate cancer during the past two decades. Many cancers identified by repeated PSA testing are small volume, low-grade lesions that pose little threat of progression over 15-20 years. Data from a recently reported randomized trial indicate that as many as 48 men must undergo treatment to prevent one prostate cancer-related death. Unfortunately, no test is currently available that can identify those men who have clinically significant disease. Men least likely to experience disease progression are men who harbor tumors with a Gleason score of 6 involving 2 needle cores or less; these men may want to consider active surveillance as their initial treatment option. Researchers have followed over 2,500 men on active surveillance protocols (over 200 men have been followed for >10 years). To date, prostate cancer-specific survival is over 99%. About 25% of men enrolled in active surveillance programs have abandoned this approach because of concerns about disease progression. For men harboring tumors with a Gleason score >7, data from two recently reported Swedish trials suggest lower prostate cancer-related mortality for those men receiving either surgery or radiation.