Comparison of Pathological Outcomes for Men with Low Risk Prostate Cancer from Diverse Practice Settings: Similar Results from Immediate Prostatectomy or Initial Surveillance with Delayed Prostatectomy

Surgical waiting times and all-cause mortality in patients with non-metastatic renal cell carcinoma

OBJECTIVE

To examine the association between surgical waiting times (SWTs) and all-cause mortality (ACM) in non-metastatic patients with RCC, in relation to tumour stage.

PATIENTS AND METHODS

This nation-wide population-based cohort study included 9,918 M0 RCC patients registered in the National Swedish Kidney Cancer Register, between 2009 and 2021, followed-up for ACM until 9 December 2021, and having measured SWTs. The associations between primarily SWTs from date of radiological diagnosis to date of surgery (WRS) and secondarily SWTs from date of radiological diagnosis to date of treatment decision (WRT) and date of treatment decision to date of surgery (WTS), in relation to ACM, were analysed using Cox regression analysis, adjusted for clinical and demographic characteristics, stratified and unstratified according to T-stage.

RESULTS

During a mean follow-up time of 5 years (49,873 person-years), 23% (n = 2291) of the patients died. The adjusted hazard ratio (AHR) for WRS (months) for all patients was 1.03 (95% confidence interval [CI] = 1.02-1.04; p < 0.001). When subdividing WRS on T-stage, the AHRs were 1.03 (95% CI = 1.01-1.04; p < 0.001) and 1.05 (95% CI = 1.02-1.08; p = 0.003) for stages T1 and T3, respectively, while non-significant for T2 (p = 0.079) and T4 (p = 0.807). Similar results were obtained for WRT and WTS.

CONCLUSIONS

Prolonged SWTs significantly increased the risk of early overall death among patients with RCC. The increased risk of early death from any cause show the importance of shortening SWTs in clinical work of patients with this malignant disease.

Delayed radical prostatectomy after a period of active surveillance is not associated with the use of secondary treatments compared with immediate prostatectomy

BACKGROUND

We evaluated the use of secondary treatments in men with grade group (GG) 1 PC following a period of active surveillance (AS) compared with men undergoing immediate radical prostatectomy (RP) to evaluate what is potentially lost in terms of cancer control, if a patient trials AS and transitions to treatment.

METHODS

We reviewed the Michigan Urological Surgery Improvement Collaborative (MUSIC) registry for men with GG1 PC undergoing RP from April 2012 to July 2018. Men were classified into groups based on time from diagnosis to RP: immediate (surgery within 1 year of diagnosis) and delayed RP (surgery >1 year after initiation of AS). Time to secondary treatment was estimated using Kaplan-Meier curves and compared using the log-rank test. A multivariable Cox proportional hazards model was fit to assess the association between timing of RP and use of secondary treatments. A chi-squared test was used to assess the association between delayed RP and adverse pathology.

RESULTS

We identified 1878 men that underwent an RP during the study period, of which 1489 (79%) underwent immediate RP and 389 (21%) underwent delayed RP. The incidence of adverse pathology was higher in men with delayed versus immediate RP (49% vs. 36%, p < 0.0001, respectively). However, we noted only a small absolute difference in the estimated 24-month secondary treatment-free probability between men with delayed versus immediate RP (93% and 96%, respectively). On multivariable analysis, delayed RP was associated with increased use of secondary treatments (hazard ratio = 1.94, 95% confidence interval = 1.23-3.06, p = 0.004).

CONCLUSIONS

The use of secondary treatment after RP in men with GG1 PC undergoing immediate or delayed prostatectomy was rare. These data suggest that the burden of treatment is near equivalent in patients who progress to treatment on AS compared with those who underwent immediate RP.

[Active surveillance of prostate cancer : An update]

Prostate cancer is a heterogeneous disease. In cases of low-risk prostate cancer, active surveillance represents an attractive alternative treatment. Significant complications of a definitive treatment can therefore be delayed or completely avoided. Despite strict inclusion criteria for active surveillance, the diagnosis of low-risk prostate cancer can be inaccurate and there is therefore a risk of missing the optimal point in time for definitive treatment. Multimodal diagnostics and continuous aftercare are therefore crucial.

Does time from diagnosis to treatment of high- or very-high-risk prostate cancer affect outcome?

OBJECTIVE

To determine whether time from diagnosis to treatment impacted outcomes in a multicentre cohort of high- and very-high-risk (VHR) patients with prostate cancer undergoing radical prostatectomy (RP).

PATIENTS AND METHODS

In all, 1392 patients from three tertiary centres who underwent RP for either high-risk or VHR disease, from 2005 to 2015, were identified. The cohort was divided into tertiles based on time from diagnostic biopsy to RP. Cumulative incidence of biochemical recurrence (BCR), metastasis, and prostate cancer-specific mortality (PCSM) were calculated for each tertile. The Kaplan-Meier method was used to evaluate for differences in all-cause mortality (ACM) amongst tertiles. Competing risks regression models, as well as Cox proportional hazards regression models, were fitted to assess the association between time-to-event outcomes and patient characteristics.

RESULTS

The median (interquartile range [IQR]) time from biopsy to RP was 68 (50-94) days. The median (IQR) follow-up was 31 (12.1-55.7) months. The cumulative incidence of BCR (P = 0.14), metastasis (P = 0.15), and PCSM (P = 0.69) did not differ amongst time-to-treatment tertiles of VHR patients. Also, Kaplan-Meier estimates of ACM (P = 0.53) did not differ amongst time-to-treatment tertiles. Similarly, BCR, metastasis, PCSM, and ACM did not significantly differ amongst time-to-treatment tertiles in multivariable modelling.

CONCLUSION

In this pooled meta-dataset of patients with high-risk or VHR prostate cancer, time from diagnosis to RP did not appear to significantly contribute to differences in clinical outcomes. This finding supports the safety of enrollment of such patients into neoadjuvant clinical trials.

Optimizing Time to Treatment to Achieve Durable Biochemical Disease Control after Surgery in Prostate Cancer: A Multi-Institutional Cohort Study

BACKGROUND

The impact of treatment delays on prostate cancer-specific outcomes remains ill-defined. This study investigates the effect of time to treatment on biochemical disease control after prostatectomy.

METHODS

This retrospective study includes 1,807 patients who received a prostatectomy as a primary treatment at two large tertiary referral centers from 1987 to 2015. Multivariate cox model with restricted cubic spline was used to identify optimal time to receive treatment and estimate the risk of biochemical recurrence.

RESULTS

Median follow-up time of the study was 46 (interquartile range, 18-86) months. Time to treatment was subcategorized based on multivariate cubic spline cox model. In multivariate spline model, adjusted for all the pertinent pretreatment variables, inflection point in the risk of biochemical recurrence was observed around 3 months, which further increased after 6 months. Based on spline model, time to treatment was then divided into 0 to 3 months (61.5%), >3 to 6 months (31.1%), and 6 months (7.4%). In the adjusted cox model, initial delays up to 6 months did not adversely affect the outcome; however, time to treatment >6 months had significantly higher risk of biochemical recurrence (HR, 1.84; 95% confidence interval, 1.30-2.60; P < 0.01).

CONCLUSIONS

The initial delays up to 6 months in prostate cancer primary treatment may be sustainable without adversely affecting the outcome. However, significant delays beyond 6 months can unfavorably affect biochemical disease control.

IMPACT

Time to treatment can aid clinicians in the decision-making of prostate cancer treatment recommendation and educate patients against unintentional treatment delays.

18F-Positron Emitting/Trimethine Cyanine-Fluorescent Contrast for Image-Guided Prostate Cancer Management

[^18/19F]-4, an anionic GCPII/PSMA inhibitor for image-guided intervention in prostate cancer, is described. [¹⁹F]-4 is radiolabeled with a radiochemical yield that is ≥27% and a molar activity of 190 ± 50 mCi/μmol in a <1 h, one-step, aqueous isotopic exchange reaction. [¹⁹F]-4 allows PSMA expression to be imaged by fluorescence (FL) and [¹⁸F]-PET. PC3-PIP (PSMA-positive, EC₅₀ = 6.74 ± 1.33 nM) cancers are specifically delineated in mice that bear 3 million (18 mg) PC3-PIP and PC3 (control, PSMA-negative) cells. Colocalization of [^18/19F]-4 PET, fluorescence, scintillated biodistribution, and PSMA expression are observed.

Curative Radiation Therapy at Time of Progression Under Active Surveillance Compared With Up-front Radical Radiation Therapy for Prostate Cancer

PURPOSE

To describe and compare outcomes in men with initially presumed indolent prostate cancer receiving definitive radiation therapy after active surveillance (AS) versus those in a risk-matched cohort undergoing up-front radiation therapy.

METHODS AND MATERIALS

Men prospectively enrolled in an AS program between 1992 and 2014 and subsequently undergoing curative radiation therapy (ie, image guided radiation therapy [IGRT] or low-dose-rate brachytherapy [LDR-BT]) were identified. Biochemical relapse-free rate (bRFR), metastasis-free rate (mFR), and overall survival (OS) were compared against a cohort of men treated up front, matched by age, clinical prognostic indices (risk group, prostate-specific antigen, cT category, Gleason score, percentage of involved biopsy cores), and radiation therapy modality.

RESULTS

Of 1070 patients in the AS registry, 200 underwent definitive radiation therapy (143 IGRT and 57 LDR-BT) after a median of 32.9 (interquartile range [IQR] 20.6-59.8) months on surveillance. Main reasons for treatment were grade and volume upgrading (57.5% and 26%, respectively). Median follow-up after radiation therapy was 4.9 (IQR 3.1-7.5) years. At 5 years the bRFR, mFR, and OS were, respectively, 97%, 99%, and 98.5%. No patient died of prostate cancer. Adequate risk-matching was confirmed in an independent cohort comprising 359 patients receiving up-front IGRT (71%) or LDR-BT (29%) and followed for a median of 9 (IQR 3.1-7.5) years. There was no difference in the disease-specific outcomes (bRFR, mFR) between the 2 cohorts (Gray's P value of .257 and .934, respectively). In multivariate analyses, timing of radical radiation therapy (deferred vs up-front) was not correlated to biochemical relapse or metastases occurrence.

CONCLUSIONS

Curative-intent radiation therapy (ie, dose-escalated IGRT or LDR-BT) after a period of AS renders excellent oncologic outcomes at 5 years. Deferring radical therapy after a period of AS does not seem to result in inferior oncologic outcomes compared with patients with similar risk characteristics undergoing up-front treatment.

Low-risk Prostate Cancer: Identification, Management, and Outcomes

CONTEXT

The incidence of low-risk prostate cancer (PCa) has increased as a consequence of prostate-specific antigen testing.

OBJECTIVE

In this collaborative review article, we examine recent literature regarding low-risk PCa and the available prognostic and therapeutic options.

EVIDENCE ACQUISITION

We performed a literature review of the Medline, Embase, and Web of Science databases. The search strategy included the terms: prostate cancer, low risk, active surveillance, focal therapy, radical prostatectomy, watchful waiting, biomarker, magnetic resonance imaging, alone or in combination.

EVIDENCE SYNTHESIS

Prospective randomized trials have failed to show an impact of radical treatments on cancer-specific survival in low-risk PCa patients. Several series have reported the risk of adverse pathologic outcomes at radical prostatectomy. However, it is not clear if these patients are at higher risk of death from PCa. Long-term follow-up indicates the feasibility of active surveillance in low-risk PCa patients, although approximately 30% of men starting active surveillance undergo treatment within 5 yr. Considering focal therapies, robust data investigating its impact on long-term survival outcomes are still required and therefore should be considered experimental. Magnetic resonance imaging and tissue biomarkers may help to predict clinically significant PCa in men initially diagnosed with low-risk disease.

CONCLUSIONS

The incidence of low-risk PCa has increased in recent years. Only a small proportion of men with low-risk PCa progress to clinical symptoms, metastases, or death and prospective trials have not shown a benefit for immediate radical treatments. Tissue biomarkers, magnetic resonance imaging, and ongoing surveillance may help to identify those men with low-risk PCa who harbor more clinically significant disease.

PATIENT SUMMARY

Low-risk prostate cancer is very common. Active surveillance has excellent long-term results, while randomized trials have failed to show a beneficial impact of immediate radical treatments on survival. Biomarkers and magnetic resonance imaging may help to identify which men may benefit from early treatment.

Management and outcomes of Gleason six prostate cancer detected on needle biopsy: A single-surgeon experience over 6 years

Objective

To assess the management and oncological outcomes in men diagnosed with Gleason score (GS) 6 prostate cancer on needle biopsy in a regional centre, as compared with published international data.

Materials and methods

A retrospective analysis was conducted of patients who were diagnosed with GS 6 prostate cancer via transrectal ultrasound-guided or transperineal biopsy between June 2009 and September 2015 under the care of a single surgeon. Data were obtained from a prospectively collected database.

Results

A total of 166 patients were diagnosed with GS 6 prostate cancer. The mean age was 61 (range 46-79) years, with mean prostate-specific antigen of 6.7 (0.91-26.8) ng/mL at diagnosis. Of 166 patients, 117 (70.5%) patients were enrolled into the active surveillance program with 82 (70%) meeting Prostate Cancer Research International Active Surveillance (PRIAS) criteria, 44 patients underwent immediate definitive treatment (88.6% radical prostatectomy and 9.1% radiotherapy) and five watchful waiting. With a median follow-up of 1.8 years, 37 (31.6%) patients on AS had definitive treatment [30 cases (81%) were attributable to disease progression, 4 cases (10.8%) to an abnormal magnetic resonance imaging result and 3 cases (8.1%) for patient preference]. In the 35 patients who underwent radical prostatectomy immediately after diagnosis, the GS was ≥7 in 29 cases (82.9%), and the final pathology was pT3a in 16 (51.6%) and pT3b in one (2.9%). In patients who underwent radical prostatectomy after being on AS, the proportion of GS ≥7 prostate cancer was 29/32 (90.6%), with pT3a in six (18.8%) and pT3b in three (9.4%) cases. Overall, 23.5% of patients had a multiparametric magnetic resonance imaging scan.

Conclusion

This single-surgeon cohort of GS 6 prostate cancer patients demonstrates a high proportion of cases managed with active surveillance, with comparable rates to international literature. The majority of cases who underwent immediate definitive treatment had significant disease, indicating that patients are being appropriately selected for active surveillance.

Evaluation of Prostate Cancer Risk Calculators for Shared Decision Making Across Diverse Urology Practices in Michigan

OBJECTIVE

To compare the predictive performance of a logistic regression model developed with contemporary data from a diverse group of urology practices to that of the Prostate Cancer Prevention Trial (PCPT) Risk Calculator version 2.0.

MATERIALS AND METHODS

With data from all first-time prostate biopsies performed between January 2012 and March 2015 across the Michigan Urological Surgery Improvement Collaborative (MUSIC), we developed a multinomial logistic regression model to predict the likelihood of finding high-grade cancer (Gleason score ≥7), low-grade cancer (Gleason score ≤6), or no cancer on prostate biopsy. The performance of the MUSIC model was evaluated in out-of-sample data using 10-fold cross-validation. Discrimination and calibration statistics were used to compare the performance of the MUSIC model to that of the PCPT risk calculator in the MUSIC cohort.

RESULTS

Of the 11,809 biopsies included, 4289 (36.3%) revealed high-grade cancer; 2027 (17.2%) revealed low-grade cancer; and the remaining 5493 (46.5%) were negative. In the MUSIC model, prostate-specific antigen level, rectal examination findings, age, race, and family history of prostate cancer were significant predictors of finding high-grade cancer on biopsy. The 2 models, based on similar predictors, had comparable discrimination (multiclass area under the curve = 0.63 for the MUSIC model and 0.62 for the PCPT calculator). Calibration analyses demonstrated that the MUSIC model more accurately predicted observed outcomes, whereas the PCPT risk calculator substantively overestimated the likelihood of finding no cancer while underestimating the risk of high-grade cancer in this population.

CONCLUSION

The PCPT risk calculator may not be a good predictor of individual biopsy outcomes for patients seen in contemporary urology practices.