Tineke Wolters

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.

Anxiety and Distress During Active Surveillance for Early Prostate Cancer

Patients on active surveillance (AS) for early prostate cancer (PC) may experience feelings of anxiety and distress while living with “untreated” cancer. In this study, these feelings were quantified, and their associations with various psychologic, medical, demographic, and decision‐related factors were assessed.

A risk-based strategy improves prostate-specific antigen-driven detection of prostate cancer.

BACKGROUND Screening for prostate cancer (PC) is controversial due to uncertainties about its efficiency. OBJECTIVE We aimed to develop strategies to reduce the number of unnecessary biopsies while still detecting most clinically important PC cases. DESIGN, SETTING, AND PARTICIPANTS In 1850 men initially screened and biopsied (prostate-specific antigen [PSA] value > or =3.0 ng/ml) in the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer, we calculated both the probability of having a positive lateralized sextant biopsy [P(biop+)] and the probability of having an indolent cancer [P(ind)] if PC was detected at biopsy (n=541). Analyses of repeat screening included 225 cancers in 1201 men. INTERVENTIONS The P(biop+) was based on applying a logistic regression model that included ultrasound volume, digital rectal exam, and transrectal ultrasound in addition to the PSA value. The P(ind) was based on a recently validated nomogram. MEASUREMENTS AND LIMITATIONS: At initial screening the fraction of positive biopsies was 29% (541 of 1850). Applying an additional P(biop+) cut-off of 12.5% implied that 613 of the 1850 men (33%) would not have been biopsied. This would result in an increase in the positive predictive value (PPV) to 38% (468 of 1237). At repeat screening a similar P(biop+) cut-off would result in an increase in the PPV from 19% (225 of 1201) to 25% (188 of 760). Thirteen percent of PC cases would not have been diagnosed, of which 70% (initial screening) and 81% (repeat screening) could be considered as potentially indolent. None of the deadly PC cases would have been missed. A PSA cut-off of > or =4.0 ng/ml resulted in similar numbers of biopsied cases saved but considerably higher numbers of missed diagnoses. CONCLUSIONS An individualized screening algorithm using other available prebiopsy information in addition to PSA level can result in a considerable reduction of unnecessary biopsies. Very few important PC cases, for which diagnosis at a subsequent screening visit might be too late for treatment with curative intent, would be missed.

Early Detection of Prostate Cancer in 2007: Part 1: PSA and PSA Kinetics

OBJECTIVE This is the first of two review papers attempting to clarify the best way to detect prostate cancer (PCa) in 2007. Screening for PCa has not yet been shown to lower PCa mortality. Still, opportunistic screening is wide spread in Europe and in most other parts of the world. METHODS Current literature and data from screening studies are reviewed and discussed. Prostate-specific antigen (PSA) has been and remains one of the corner stones of early detection of PCa. Traditionally used cut-off values cannot be applied in an uncritical fashion after it was shown that a significant amount of overdiagnosis and that large proportions of cancers and poorly differentiated cancers are present in the low PSA ranges. The paper addresses the continued relevance of PSA cut-off values. The diagnostic value of PSA velocity is reviewed in conjunction with PSA cut-off values and as a possible replacement of total PSA. A need for more selective screening in the low PSA ranges is pointed out. RESULTS AND CONCLUSIONS The data show that men presenting initially with PSA values below 1 do not have to be rescreened for a period of 8 yr. In the PSA range 1-2.9 ng/ml, new parameters are needed that improve specificity and are selective for screening for aggressive lesions. PSA velocity so far has not been shown to be useful in the early detection of PCa but may be useful in detecting aggressive PCa selectively. For the time being, it seems sensible to continue using PSA cut-off values such as 3.0 or 4.0 ng/ml provided overtreatment is decreased by using available nomograms.

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.

Review – Prostate CancerEarly Detection of Prostate Cancer in 2007: Part 1: PSA and PSA Kinetics

OBJECTIVE This is the first of two review papers attempting to clarify the best way to detect prostate cancer (PCa) in 2007. Screening for PCa has not yet been shown to lower PCa mortality. Still, opportunistic screening is wide spread in Europe and in most other parts of the world. METHODS Current literature and data from screening studies are reviewed and discussed. Prostate-specific antigen (PSA) has been and remains one of the corner stones of early detection of PCa. Traditionally used cut-off values cannot be applied in an uncritical fashion after it was shown that a significant amount of overdiagnosis and that large proportions of cancers and poorly differentiated cancers are present in the low PSA ranges. The paper addresses the continued relevance of PSA cut-off values. The diagnostic value of PSA velocity is reviewed in conjunction with PSA cut-off values and as a possible replacement of total PSA. A need for more selective screening in the low PSA ranges is pointed out. RESULTS AND CONCLUSIONS The data show that men presenting initially with PSA values below 1 do not have to be rescreened for a period of 8 yr. In the PSA range 1-2.9 ng/ml, new parameters are needed that improve specificity and are selective for screening for aggressive lesions. PSA velocity so far has not been shown to be useful in the early detection of PCa but may be useful in detecting aggressive PCa selectively. For the time being, it seems sensible to continue using PSA cut-off values such as 3.0 or 4.0 ng/ml provided overtreatment is decreased by using available nomograms.

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.

The effect of study arm on prostate cancer treatment in the large screening trial ERSPC

Prostate cancer (PC) mortality is the most valid end‐point in screening trials, but could be influenced by the choice of initial treatment if treatment has an effect on mortality. In this study, PC treatment was compared between the screening and control arms in a screening trial. Data were collected from the European Randomized Study of Screening for Prostate Cancer (ERSPC). The characteristics and initial treatment of PC cases detected in the screening and the control arm were compared. Polytomous logistic regression analysis was used to assess the influence of study arm on treatment, adjusting for potential confounders and with statistical imputation of missing values. A total of 8,389 PC cases were detected, 5,422 in the screening arm and 3,145 in the control arm. Polytomous regression showed that trial arm was associated with treatment choice after correction for missing values, especially in men with high‐risk PC. A control subject with high‐risk PC was more likely than a screen subject to receive radiotherapy (OR: 1.43, 95% CI: 1.01–2.05, p = 0.047), expectant management (OR: 2.92, 95% CI: 1.33–6.42, p = 0.007) or hormonal treatment (OR: 1.77, 95% CI: 1.07–2.94, p = 0.026) instead of radical prostatectomy. However, trial arm had only a minor role in treatment choice compared to other variables. In conclusion, a small effect of trial arm on treatment choice was seen, particularly in men with high‐risk PC. Therefore, differences in treatment between arms are unlikely to play a major role in the interpretation of the results of the ERSPC.

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-Specific Antigen Velocity for Early Detection of Prostate Cancer: Result from a Large, Representative, Population-based Cohort

BACKGROUND It has been suggested that changes in prostate-specific antigen (PSA) over time (ie, PSA velocity [PSAV]) aid prostate cancer detection. Some guidelines do incorporate PSAV cut points as an indication for biopsy. OBJECTIVE To evaluate whether PSAV enhances prediction of biopsy outcome in a large, representative, population-based cohort. DESIGN, SETTING, AND PARTICIPANTS There were 2742 screening-arm participants with PSA <3 ng/ml at initial screening in the European Randomized Study of Screening for Prostate Cancer in Rotterdam, Netherlands, or Göteborg, Sweden, and who were subsequently biopsied during rounds 2-6 due to elevated PSA. MEASUREMENTS Total, free, and intact PSA and human kallikrein 2 were measured for 1-6 screening rounds at intervals of 2 or 4 yr. We created logistic regression models to predict prostate cancer based on age and PSA, with or without free-to-total PSA ratio (%fPSA). PSAV was added to each model and any enhancement in predictive accuracy assessed by area under the curve (AUC). RESULTS AND LIMITATIONS PSAV led to small enhancements in predictive accuracy (AUC of 0.569 vs 0.531; 0.626 vs 0.609 if %fPSA was included), although not for high-grade disease. The enhancement depended on modeling a nonlinear relationship between PSAV and cancer. There was no benefit if we excluded men with higher velocities, which were associated with lower risk. These results apply to men in a screening program with elevated PSA; men with prior negative biopsy were not evaluated in this study. CONCLUSIONS In men with PSA of about ≥3 ng/ml, we found little justification for formal calculation of PSAV or for use of PSAV cut points to determine biopsy. Informal assessment of PSAV will likely aid clinical judgment, such as a sudden rise in PSA suggesting prostatitis, which could be further evaluated before biopsy.