Relapse after radical prostatectomy correlates with preoperative PSA velocity and tumor volume: Results from a screening population

Tissue- and Liquid-Based Biomarkers in Prostate Cancer Precision Medicine

Worldwide, prostate cancer (PC) is the second-most-frequently diagnosed male cancer and the fifth-most-common cause of all cancer-related deaths. Suspicion of PC in a patient is largely based upon clinical signs and the use of prostate-specific antigen (PSA) levels. Although PSA levels have been criticised for a lack of specificity, leading to PC over-diagnosis, it is still the most commonly used biomarker in PC management. Unfortunately, PC is extremely heterogeneous, and it can be difficult to stratify patients whose tumours are unlikely to progress from those that are aggressive and require treatment intensification. Although PC-specific biomarker research has previously focused on disease diagnosis, there is an unmet clinical need for novel prognostic, predictive and treatment response biomarkers that can be used to provide a precision medicine approach to PC management. In particular, the identification of biomarkers at the time of screening/diagnosis that can provide an indication of disease aggressiveness is perhaps the greatest current unmet clinical need in PC management. Largely through advances in genomic and proteomic techniques, exciting pre-clinical and clinical research is continuing to identify potential tissue, blood and urine-based PC-specific biomarkers that may in the future supplement or replace current standard practices. In this review, we describe how PC-specific biomarker research is progressing, including the evolution of PSA-based tests and those novel assays that have gained clinical approval. We also describe alternative diagnostic biomarkers to PSA, in addition to biomarkers that can predict PC aggressiveness and biomarkers that can predict response to certain therapies. We believe that novel biomarker research has the potential to make significant improvements to the clinical management of this disease in the near future.

Association of Prostate-Specific Antigen Velocity With Clinical Progression Among African American and Non-Hispanic White Men Treated for Low-Risk Prostate Cancer With Active Surveillance

IMPORTANCE

The association of prostate-specific antigen velocity (PSAV) with clinical progression in patients with localized prostate cancer managed with active surveillance remains unclear and, to our knowledge, has not been studied in African American patients.

OBJECTIVES

To test the hypothesis that PSAV is associated with clinical progression in patients with low-risk prostate cancer treated with active surveillance and to identify differences between African American and non-Hispanic White patients.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective population-based cohort study using patient records from the Veterans Heath Administration Informatics and Computing Infrastructure on 5296 patients with a diagnosis of localized prostate cancer from January 1, 2001, to December 31, 2015, who were managed with active surveillance. Follow-up extended through March 31, 2020. Low-risk prostate cancer was defined as International Society of Urologic Pathology grade group (GG) 1 clinical tumor stage 2A or lower, PSA level of 10 ng/dL or lower, active surveillance, and no definitive treatment within the first year after diagnosis with at least 1 additional staging biopsy after diagnostic biopsy.

EXPOSURES

Prostate-specific antigen testing.

MAIN OUTCOMES AND MEASURES

The primary outcome was GG progression detected after repeated biopsy or prostatectomy, defined as GG2 or higher or GG3 or higher. The secondary outcome was incident metastases. Cumulative incidence functions and multivariable Cox proportional hazards regression models were used to test associations between PSAV and outcomes.

RESULTS

The final cohort (n = 5296) included 3919 non-Hispanic White men (74.0%; mean [SD] age, 65.7 [5.8] years) and 1377 African American men (26.0%; mean [SD] age, 62.8 [6.6] years). Compared with African American patients, non-Hispanic White patients were older (mean [SD] age, 65.7 [5.8] years vs 62.8 [6.6] years; P < .001), presented with higher cT stage (stage T2, 608 [15.5%] vs 111 [8.1%]; P < .001), had a higher Charlson Comorbidity Index score (1 and ≥2, 912 [23.3%] vs 273 [19.8%]; P = .002), had higher median income ($60 000 to ≥$100 000, 1223 [31.2%] vs 282 [20.5%]; P < .001), and had a higher median level of education (20% to ≥30% with college degree, 1192 [30.4%] vs 333 [24.2%]; P < .001). Progression to GG2 or higher occurred in 2062 patients (38.9%), with a cumulative incidence of 43.2%, and progression to GG3 or higher occurred in 728 patients (13.7%). Fifty-four patients (1.0%) developed metastases. On multivariable analysis, PSAV was significantly associated with progression to GG2 (hazard ratio, 1.32 [95% CI, 1.26-1.39]), GG3 (hazard ratio, 1.51 [95% CI, 1.41-1.62]), and metastases (hazard ratio, 1.38 [95% CI, 1.10-1.74]). Optimal PSAV thresholds that were associated with progression were significantly lower for African American patients (0.44 ng/mL/y) compared with non-Hispanic White patients (1.18 ng/mL/y).

CONCLUSIONS AND RELEVANCE

This study suggests that PSAV is significantly associated with grade progression among patients with low-risk prostate cancer managed with active surveillance, but at lower values for African American patients compared with non-Hispanic White patients. These data suggest that serial PSA measures may potentially substitute for multiple prostate biopsies and that African American patients may merit increased frequency of PSA testing.

A Pilot retrospective analysis of alpha-blockers on recurrence in men with localised prostate cancer treated with radiotherapy

While alpha-blockers are commonly used to reduce lower urinary tract symptoms in prostate cancer patients receiving radiotherapy, their impact on response to radiotherapy remains unknown. Therefore, this pilot study aimed to retrospectively determine if alpha-blockers use, influenced response to radiotherapy for localised prostate cancer. In total, 303 prostate cancer patients were included, consisting of 84 control (alpha-blocker naïve), 72 tamsulosin and 147 prazosin patients. The main outcomes measured were relapse rates (%), time to biochemical relapse (months) and PSA velocity (ng/mL/year). Recurrence free survival was calculated using Kaplan-Meier analysis. Prazosin significantly reduced biochemical relapse at both two and five-years (2.72%, 8.84%) compared to control (22.61%, 34.52%). Recurrence free survival was also significantly higher in the prazosin group. This remained after multivariable analysis (HR: 0.09, 95% CI: 0.04-0.26, p < 0.001). Patients receiving prazosin had a 3.9 times lower relative risk of biochemical relapse compared to control. Although not statistically significant, tamsulosin and prazosin extended recurrence free survival by 13.15 and 9.21 months respectively. We show for the first time that prazosin may reduce risk of prostate cancer recurrence and delay time to biochemical relapse and provides justification for prospective studies to examine its potential as an adjunct treatment option for localised prostate cancer.

Prostate-specific antigen velocity in diagnosis and prognosis of prostate cancer - a systematic review

Prostate-specific antigen velocity (PSAV) is widely used to detect PC and predict its progression. In this study, we qualitatively synthesized the currently available evidence from published studies regarding the PSAV role in PC. Electronic databases were searched to find relevant articles published until January 2019. Inclusion and exclusion criteria were applied to identify related papers. Eventually, data extraction followed by evidence synthesis was conducted. Full-text screening resulted in 42 included studies. Multiple definitions and intervals were used for PSAV calculation across studies. Results from the included studies were conflicting regarding the role of PSAV in detecting PC and predicting progression in active surveillance cases. However, there is evidence that PSAV may have a predictive role in post-treated men. There is no clear-cut evidence from the published literature to support the use of PSAV in clinical practice.

Prognostic significance of tumor volume in radical prostatectomy and needle biopsy specimens

PURPOSE

This review addresses the controversies that persist relating to the prognosis and reporting of tumor volume in adenocarcinoma of the prostate.

MATERIALS AND METHODS

A search was performed using the MEDLINE database and referenced lists of relevant studies to obtain articles addressing the quantification of cancer on radical prostatectomy and needle biopsy.

RESULTS

In the 2010 TNM classification system T2 tumor at radical prostatectomy is subdivided into pT2a (unilateral tumor occupying less than ½ a lobe), pT2b (unilateral tumor greater than ½ a lobe) and pT2c (bilateral tumor). This pathological substaging of T2 disease fails on several accounts. In most studies pT2b disease almost does not exist. By the time a tumor is so large that it microscopically occupies more than ½ a lobe, in the majority of cases there is bilateral (pT2c) tumor. An even greater flaw of the substaging system for stage pT2 disease is the lack of prognostic significance. In reporting pathologically organ confined cancer, it should be merely noted as pT2 without further subclassification. The data are conflicting as to the independent prognostic significance of objective measurements of tumor volume in radical prostatectomy specimens. The most likely explanation for the discordant results lies in the strong correlation of tumor volume with other prognostic markers such as extraprostatic extension and positive margins. In studies where it is statistically significant on multivariate analysis, it is unlikely that knowing tumor volume improves prediction of prognosis beyond routinely reported parameters to the degree that it would be clinically useful for an individual patient. An alternative is to record tumor volume as minimal, moderate or extensive, which gives some indication to the urologist as to the extent of disease. Not only does providing an objective measurement not add useful prognostic information beyond what is otherwise routinely reported by the pathologist, but many objective measurements done in routine practice will likely not be an accurate indicator of the true tumor volume. There is also a lack of consensus regarding the best method of measuring tumor length when there are multiple foci in a single core separated by benign intervening prostatic stroma. Some pathologists, this author included, consider discontinuous foci of cancer as if it was 1 uninterrupted focus, the rationale being that these discontinuous foci are undoubtedly the same cancer going in and out of the plane of section. Measuring the cancer from where it starts to where it ends on the core gives the minimal length of cancer in the prostate. Others measure each focus individually, and the sum of these measurements is considered the cancer length on the core. Quantifying cancer with an ocular micrometer to record the total length or percent length of cancer is time-consuming, and the data are conflicting whether this is superior to other, simpler methods and whether any potential differences in predictive accuracy would translate into changes in clinical management. It is recommended that at a minimum the number of positive cores be recorded, unless fragmented involved cores preclude evaluation, along with at least 1 other more detailed measurement such as the percent of core involvement or length of cancer.

CONCLUSIONS

Consensus has been reached on some of the issues relating to quantifying tumor volume in prostate cancer, such as the lack of utility of substaging pT2 disease. Other questions such as whether to include or subtract intervening benign prostate tissue on prostate needle cores will require additional studies. Finally, matters such as the need to quantify cancer at radical prostatectomy or which method of quantifying cancer on needle biopsy is superior will likely remain contentious due to the close interrelationship and redundancy of prognostic variables.

Role of PSA velocity in predicting pathologic upgrade for Gleason 6 prostate cancer

BACKGROUND

Pathologic upgrading to Gleason 7 or higher on radical prostatectomy (RP) specimens occurs in many patients with Gleason 6 prostate cancer on preoperative biopsy. We evaluated whether biopsy characteristics and preoperative factors, including preoperative PSA velocity (PSAV), are predictive of pathologic upgrading.

MATERIALS AND METHODS

We identified 235 consecutive Gleason 6 prostate cancer patients who underwent biopsies at our institution, had multiple pre-biopsy PSA values, and eventually underwent RP. Preoperative biopsy, clinical characteristics, and PSAV were analyzed to determine the risk of pathologic upgrading or extracapsular extension. These clinical factors were evaluated for association with biochemical recurrence following RP.

RESULTS

Overall, 48% of patients were upgraded to Gleason grade 7 or higher following RP. Median PSAV was 0.61 ng/mL/y, and PSAV was similar between upgraded and non-upgraded patients (1.01 vs. 0.78, P = 0.1). PSA velocity level was not associated with extracapsular disease (P = 0.4). PSA velocity > 1 was associated with biochemical recurrence (HR 3.23, P = 0.01) but this was not statistically significant in a multivariable model. Increasing PSA density (HR 2.18, P < 0.001), bilateral cores positive (HR 1.89, P < 0.05), and any biopsy core involvement > 50% (HR 2.52, P < 0.05) were most associated with pathologic upgrading. On multivariate analysis, only bilateral cancer detection at biopsy (HR 1.90, P < 0.05) significantly predicted upgrading.

CONCLUSIONS

PSAV has a limited role in predicting Gleason 6 upgrading. Patients with bilateral cancer detected on transrectal biopsy should be encouraged to have radical local therapy due to high risk of harboring more aggressive disease.

[Prostate carcinoma]

Prostate cancer is the most common malignancy in men in Europe, North America, and in some African states. Early diagnosis in an asymptomatic stage is possible through the combination of digitorectal examination, PSA serum testing, and systematic biopsy. However, general screening is so far not recommended by the Urologic Societies, because the efficiency is not yet proved. Imaging is also not recommended for first-line screening. Novel functional methods of transrectal ultrasound (TRUS) and endorectal MRI can improve accuracy of tumor detection to more than 90% and can be used for TRUS- and now also MRI-guided biopsy leading to two- to threefold higher tumor detection rates. There is general agreement that all men over 50 years of age should be informed about the possibilities, benefits, and risks of the available methods for early tumor detection.

Is prostate-specific antigen velocity selective for clinically significant prostate cancer in screening? European Randomized Study of Screening for Prostate Cancer (Rotterdam)

BACKGROUND

The value of prostate-specific antigen velocity (PSAV) in screening for prostate cancer (PCa) and especially for clinically significant PCa is unclear.

OBJECTIVE

To assess the value of PSAV in screening for PCa. Specifically, the role of PSAV in lowering the number of unnecessary biopsies and reducing the detection rate of indolent PCa was evaluated.

DESIGN, SETTING, AND PARTICIPANTS

All men included in the study cohort were participants in the European Randomized Study of Screening for Prostate Cancer (ERSPC), Rotterdam section.

INTERVENTION

During the first and second screening round, a PSA test was performed on 2217 men, and all underwent a biopsy during the second screening round 4 yr later.

MEASUREMENTS

PSAV was calculated and biopsy outcome was classified as benign, possibly indolent PCa, or clinically significant PCa.

RESULTS AND LIMITATIONS

A total of 441 cases of PCa were detected, 333 were classified as clinically significant and 108 as possibly indolent. The use of PSAV cut-offs reduced the number of biopsies but led to important numbers of missed (indolent and significant) PCa. PSAV was predictive for PCa (OR: 1.28, p<0.001) and specifically for significant PCa (OR: 1.46, p<0.001) in univariate analyses. However, multivariate analyses using age, PSA, prostate volume, digital rectal examination and transrectal ultrasonography outcome, and previous biopsy (yes/no) showed that PSAV was not an independent predictor of PCa (OR: 1.01, p=0.91) or significant PCa (OR: 0.87, p=0.30).

CONCLUSIONS

The use of PSAV as a biopsy indicator would miss a large number of clinically significant PCa cases with increasing PSAV cut-offs. In this study, PSAV was not an independent predictor of a positive biopsy in general or significant PCa on biopsy. Therefore, PSAV does not improve the ERSPC screening algorithm.

Patient selection, cancer control, and complications after salvage local therapy for postradiation prostate-specific antigen failure

Among men who experience prostate-specific antigen (PSA) failure after external beam radiation or brachytherapy (RT), many will harbor occult micrometastases; however, a significant minority will have a true local-only failure and, thus, potentially may benefit from a salvage local therapy. Those most likely to have a local-only failure initially have low-risk disease (PSA < 10 ng/mL, Gleason score < or =6, clinical T1c or T2a tumor status), pretreatment PSA velocity < 2.0 ng/mL per year at the time of initial presentation, interval to PSA failure > 3 years, PSA doubling time > 12 months, negative bone scan and pelvic imaging, and positive rebiopsy. In addition, men with presalvage PSA levels > 10 ng/mL, presalvage T3/T4 disease, or presalvage Gleason scores > or =7 on a rebiopsy sample without significant RT effects are unlikely to be cured by salvage local therapy. Based on a review of all series of post-RT salvage prostatectomy, cryosurgery, and brachytherapy published in English since 1990, morbidity can be substantial. Although urinary incontinence appeared to be greater after salvage prostatectomy (41%) or cryosurgery (36%) than after brachytherapy (6%), patients who received salvage brachytherapy faced a 17% risk of grade 3 or 4 genitourinary complications and a fistula risk that averaged 3.4% across all series. From this review, the authors concluded that prospective randomized studies are needed to determine the relative efficacy of the 3 major local salvage modalities and that additional research is needed to identify factors associated with an increased risk of significant complications to improve patient selection and to augment the benefit/risk ratio associated with attempts to cure local-only recurrences after radiation therapy.