Pim J. van Leeuwen

A Critical Analysis of the Tumor Volume Threshold for Clinically Insignificant Prostate Cancer Using a Data Set of a Randomized Screening Trial

PURPOSE The identification of clinically insignificant prostate cancer could help avoid overtreatment. Current criteria for insignificant prostate cancer use a tumor volume threshold of less than 0.5 ml for the index tumor. In this study we reassess this tumor volume threshold for clinically insignificant prostate cancer using an independent data set. MATERIALS AND METHODS The rate of insignificant prostate cancer was calculated by modeling lifetime risk estimates of prostate cancer diagnosis in screened and nonscreened participants in a randomized prostate cancer screening trial. Using lifetime risk estimates 50.8% of screen detected prostate cancer was calculated to be clinically insignificant and the 49.2% largest tumor volume of 325 prostatectomy specimens was used to determine the threshold tumor volume for insignificant prostate cancer. Because stage and grade represent the strongest determinants of cancer aggressiveness, we also calculated the tumor volume threshold for insignificant cancer after the selection of patients with organ confined prostate cancer without Gleason pattern 4/5. The analyses were performed for total tumor volume and for index tumor volume. RESULTS The minimum threshold tumor volume of the index tumor and total tumor was 0.55 and 0.70 ml, respectively. After accounting for tumor stage and grade we obtained a threshold volume for the index tumor and total tumor of 1.3 and 2.5 ml, respectively. CONCLUSIONS We confirmed the original value of the index tumor volume threshold of 0.5 ml for insignificant prostate cancer, and we demonstrated that clinically insignificant prostate cancer may include index Gleason score 6, pT2 tumors with volumes up to at least 1.3 ml. These results suggest a reconsideration of current methods and nomograms used for pretreatment risk assessment.

Prospective Comparison of 18F-Fluoromethylcholine Versus 68Ga-PSMA PET/CT in Prostate Cancer Patients Who Have Rising PSA After Curative Treatment and Are Being Considered for Targeted Therapy

In prostate cancer with biochemical failure after therapy, current imaging techniques have a low detection rate at the prostate-specific antigen (PSA) levels at which targeted salvage therapy is effective. 11C-choline and 18F-fluoromethylcholine, though widely used, have poor sensitivity at low PSA levels. 68Ga-PSMA (Glu-NH-CO-NH-Lys-(Ahx)-[68Ga-N,N′-bis[2-hydroxy-5-(carboxyethyl)benzyl]ethylenediamine-N,N′-diacetic acid]) has shown promising results in retrospective trials. Our aim was to prospectively compare the detection rates of 68Ga-PSMA versus 18F-fluoromethylcholine PET/CT in men who were initially managed with radical prostatectomy, radiation treatment, or both and were being considered for targeted therapy. Methods: A sample of men with a rising PSA level after treatment, eligible for targeted treatment, was prospectively included. Patients on systemic treatment were excluded. 68Ga-PSMA, 18F-fluoromethylcholine PET/CT, and diagnostic CT were performed sequentially on all patients between January and April 2015, and the images were assessed by masked, experienced interpreters. The findings and their impact on management were documented, together with the results of histologic follow-up when feasible. Results: In total, 38 patients were enrolled. Of these, 34 (89%) had undergone radical prostatectomy and 4 (11%) had undergone radiation treatment. Twelve (32%) had undergone salvage radiation treatment after primary radical prostatectomy. The mean PSA level was 1.74 ± 2.54 ng/mL. The scan results were positive in 26 patients (68%) and negative with both tracers in 12 patients (32%). Of the 26 positive scans, 14 (54%) were positive with 68Ga-PSMA alone, 11 (42%) with both 18F-fluoromethylcholine and 68Ga-PSMA, and only 1 (4%) with 18F-fluoromethylcholine alone. When PSA was below 0.5 ng/mL, the detection rate was 50% for 68Ga-PSMA versus 12.5% for 18F-fluoromethylcholine. When PSA was 0.5–2.0 ng/mL, the detection rate was 69% for 68Ga-PSMA versus 31% for 18F-fluoromethylcholine, and when PSA was above 2.0, the detection rate was 86% for 68Ga-PSMA versus 57% for 18F-fluoromethylcholine. On lesion-based analysis, 68Ga-PSMA detected more lesions than 18F-fluoromethylcholine (59 vs. 29, P < 0.001). The tumor-to-background ratio in positive scans was higher for 68Ga-PSMA than for 18F-fluoromethylcholine (28.6 for 68Ga-PSMA vs. 9.4 for 18F-fluoromethylcholine, P < 0.001). There was a 63% (24/38 patients) management impact, with 54% (13/24 patients) being due to 68Ga-PSMA imaging alone. Histologic follow-up was available for 9 of 38 patients (24%), and 9 of 9 68Ga-PSMA–positive lesions were consistent with prostate cancer (68Ga-PSMA was true-positive). The lesion positive on 18F-fluoromethylcholine imaging and negative on 68Ga-PSMA imaging was shown at biopsy to be a false-positive 18F-fluoromethylcholine finding (68Ga-PSMA was true-negative). Conclusion: In patients with biochemical failure and a low PSA level, 68Ga-PSMA demonstrated a significantly higher detection rate than 18F-fluoromethylcholine and a high overall impact on management.

Performance of the Prostate Cancer Antigen 3 (PCA3) Gene and Prostate-Specific Antigen in Prescreened Men: Exploring the Value of PCA3 for a First-line Diagnostic Test

BACKGROUND The performance characteristics of serum prostate-specific antigen (PSA) as a diagnostic test for prostate cancer (PCa) are poor. The performance of the PCa antigen 3 (PCA3) gene as a primary diagnostic is unknown. OBJECTIVE Assess the value of PCA3 as a first-line diagnostic test. DESIGN, SETTING AND PARTICIPANTS Participants included men aged 63-75 who were invited for rescreening in the period from September 2007 to February 2009 within the European Randomised Study of Screening for Prostate Cancer, Rotterdam section. INTERVENTIONS Lateral sextant biopsies were performed if the serum PSA value was > or =3.0 ng/ml and/or the PCA3 score was > or =10. MEASUREMENTS Measurements included distribution and correlation of PSA value and PCA3 score and their relation to the number of cases and the characteristics of PCa detected. Additional value of PCA3 was included in men with previous negative biopsy and/or PSA <3.0 ng/ml. RESULTS AND LIMITATIONS In 721 men, all biopsied, 122 PCa cases (16.9%) were detected. Correlation between PSA and PCA3 is poor (Spearman rank correlation: ρ=0.14; p<0.0001). A PSA > or =3.0 ng/ml misses 64.7% of the total PCa that can be detected with the sextant biopsy technique and 57.9% of serious PCa (T2a or higher and/or Gleason grade > or =4, n=19), and 68.2% of biopsies could have been avoided; the respective data for PCA3 > or =35 are 32%, 26.3%, and 51.7%. Performance of PCA3 in men with low PSA (area under the curve [AUC]: 0.63) and/or previous negative biopsy (AUC: 0.68) is unclear but has limited reliability due to small numbers. CONCLUSIONS PCA3 as a first-line screening test shows improvement of the performance characteristics and identification of serious disease compared with PSA in this prescreened population.

Is delayed radical prostatectomy in men with low-risk screen-detected prostate cancer associated with a higher risk of unfavorable outcomes?†

Strategies of active surveillance (AS) of low‐risk screen‐detected prostate cancer have emerged, because the balance between survival outcomes and quality of life issues when radically treating these malignancies is disputable. Delay before radical treatment caused by active surveillance may be associated with an impaired chance of curability.

68Ga-PSMA has a high detection rate of prostate cancer recurrence outside the prostatic fossa in patients being considered for salvage radiation treatment

To examine the detection rates of 68Ga‐PSMA‐positron emission tomography (PET)/computed tomography (CT) in patients with biochemical recurrence (BCR) after radical prostatectomy (RP), and also the impact on their management.

Prospective evaluation of 68Gallium-prostate-specific membrane antigen positron emission tomography/computed tomography for preoperative lymph node staging in prostate cancer

To assess the accuracy of 68Gallium‐prostate‐specific membrane antigen (68Ga‐PSMA) positron emission tomography/computed tomography (PET/CT) for lymph node (LN) staging in intermediate‐ and high‐risk prostate cancer (PCa).

Should Pathologists Routinely Report Prostate Tumour Volume? The Prognostic Value of Tumour Volume in Prostate Cancer

BACKGROUND The independent prognostic value of tumour volume in radical prostatectomy (RP) specimens is controversial, and it remains a matter of debate whether pathologists should report a measure of tumour volume. In addition, tumour volume might be of value in substaging of pathologic tumour stage (pT2) prostate cancer (PCa). OBJECTIVE To assess the prognostic value of PCa tumour volume. DESIGN, SETTING, AND PARTICIPANTS The cohort consisted of 344 participants in the European Randomised Study of Screening for Prostate Cancer (ERSPC), Rotterdam section, whose PCa was treated with RP. Mean time of follow-up was 96.2 mo. MEASUREMENTS Tumour volume was measured in totally embedded RP specimens with a morphometric, computer-assisted method and assessed as a continuous variable, as relative tumour volume (tumour volume divided by prostate volume), and in a binary fashion (≥ 0.5 ml or < 0.5 ml). These variables were related to prostate-specific antigen (PSA) progression, local recurrence, or distant metastasis and PCa-related mortality using univariate and multivariable Cox proportional hazards analyses. The analyses were repeated in the subgroup with pT2 tumours. RESULTS AND LIMITATIONS Tumour volume was related to tumour stage, Gleason score, seminal vesicle invasion (SVI), and surgical margin status. In univariate analyses, tumour volume and relative tumour volume were predictive for all outcome variables. In multivariable analyses, including age, tumour stage, Gleason score, SVI, and surgical margin status, neither tumour volume nor relative volume were independent predictors of progression or mortality. Tumour volume ≥ 0.5 ml was predictive for PSA recurrence and local and/or distant progression in univariate analyses but not in multivariable analyses. Tumour volume was not predictive for recurrence or mortality in univariate or multivariable analyses in the pT2 subgroup. CONCLUSIONS Tumour volume did not add prognostic value to routinely assessed pathologic parameters. Therefore, there seems to be little reason to routinely measure tumour volume in RP specimens.

Prostate cancer mortality in screen and clinically detected prostate cancer: Estimating the screening benefit

BACKGROUND To estimate the benefits of prostate-specific antigen (PSA) screening on prostate cancer (Pca) metastasis and Pca-specific mortality, we compared two populations with a well-defined difference in intensity of screening. METHODS Between 1997 and 1999, a total of 11,970 men, aged 55-74 years, were included in the intervention arm of the European Randomised Study of Screening for Prostate Cancer (ERSPC) section Rotterdam. Control population consisted of 133,287 men, aged 55-74 years, between 1998 and 1999 in Northern Ireland (NI). Men were followed for Pca incidence, Pca metastasis and cause of death until 31st December 2006. RESULTS Median age in both groups was 63 years at study entry (p=0.184). In Rotterdam 94.2% of men and in NI 6% of men underwent PSA testing. In Rotterdam, 1153 men (9.6%) were diagnosed with Pca with median baseline PSA of 5.1 ng/ml. In NI, 3962 men (3.0%, p<0.001) were diagnosed with Pca with median baseline PSA of 18.0 ng/ml (p<0.001). The relative risk of Pca metastasis during observation in the intervention population compared to control population was 0.47 (95% confidence interval (CI), 0.35-0.63; p<0.001). The relative risk of Pca-specific mortality was also lower in the intervention population compared to the control population after a median follow-up of 8.5 years: 0.63 (95% CI, 0.45-0.88; p=0.008); absolute mortality reduction was 1.8 deaths per 1000 men. CONCLUSIONS A relative reduction in Pca metastasis of 53% and Pca mortality of 37% was observed in the intervention population after 8.5 years of observation. The impact of overdiagnosis, quality of life benefits and cost-effectiveness need to be assessed before population-based PSA screening can be recommended.

Eleven-Year Outcome of Patients with Prostate Cancers Diagnosed During Screening After Initial Negative Sextant Biopsies

BACKGROUND The appropriate way of biopsying a prostate remains controversial. Is sextant biopsy still adequate with repeat screening? OBJECTIVE Within the European Randomized Study of Screening for Prostate Cancer (ERSPC), lateralized sextant biopsies were applied. In this analysis we use distant end points to study the fate of prostate cancers (PCa) potentially missed by initial biopsies. DESIGN, SETTING, AND PARTICIPANTS This retrospective study included 19 970 men ages 55-74 identified from the Rotterdam population registry and screened repeatedly for PCa between 1993 and 2005. PCa detected later in men with initially negative biopsies were considered as missed. Rescreening every 4 yr and a complete follow-up of 11 yr allowed an inventory of progressive and deadly disease in these men. INTERVENTION Sextant biopsies initially, later lateralized, in screen-positive men. MEASUREMENTS The fate of PCa potentially missed by initial sextant biopsies in terms of progression-free and PCa-specific survival were the main outcome measures. Kaplan-Meier analysis was used to evaluate differences between subgroups. RESULTS AND LIMITATIONS In 3056 men with negative biopsies at the first screen, 287 PCa were subsequently detected. Of these 287 cases, 26 developed progressive disease and 7 died of PCa. Poor outcomes were encountered mainly in 20 interval cases. The seven PCa deaths in men with initially negative biopsies amounted to only 0.03% compared to the 0.35% PCa death rate in the whole population of 19 970 men. Limitations include the retrospective character of this analysis. CONCLUSIONS The number of potentially missed cancers with a poor outcome in terms of progression-free survival and deaths from PCa is very low. Despite some limitations, our data show that lateralized sextant biopsy is not obsolete if repeated screening is applied.

Performance of Prostate Cancer Antigen 3 (PCA3) and Prostate-Specific Antigen in Prescreened Men: Reproducibility and Detection Characteristics for Prostate Cancer Patients with High PCA3 Scores (≥100)

BACKGROUND Prostate cancer antigen 3 (PCA3) is considered to be prostate cancer (PCa) specific and highly overexpressed in cancer. Therefore a high PCA3 score should result in a high positive predictive value (PPV) and specificity for a positive biopsy. OBJECTIVE Our aim was to reevaluate, retest PCA3, and rebiopsy men with an initial PCA3 ≥ 100 and no PCa detected and compare the results with a random cohort of men with an initial PCA3<100. DESIGN, SETTING, AND PARTICIPANTS We invited men 63-75 yr of age with a PCA3 ≥100 for retesting and a control group with an initial PCA3 < 100 to participate in the European Randomized Study of Screening for Prostate Cancer, section Rotterdam. INTERVENTIONS Blood and urine sampling were used to determine prostate-specific antigen (PSA) and PCA3. Prostate biopsies were performed if the PSA was ≥2.5 ng/ml and/or the PCA3 score was ≥ 35. MEASUREMENTS We correlated the initial and reevaluated PCA3 scores. Our assessment of the PPV after rebiopsy was based on the newly determined PCA3 score. RESULTS AND LIMITATIONS After a mean study period of 19 mo, more cases of PCa were detected in rebiopsied men with initial PCA3 scores ≥ 100 than in the controls with PCA3 scores < 100 (30.0% vs 18.8%). Combining initial and rebiopsy data resulted in a PPV of 52.2% in men with PCA3 ≥ 100. Over time, changes in PSA and PCA3 levels were quite different. CONCLUSIONS In spite of our rescreened population, PPV and specificity were comparable with all reported studies of men with PCA3 scores ≥ 100. These findings do not explain why these PCA3 scores were excessively high in spite of the absence of biopsy-detectable PCa.