Predictors of biochemical outcome with salvage conformal radiotherapy after radical prostatectomy for prostate cancer

Unveiling cancer dormancy: Intrinsic mechanisms and extrinsic forces

Tumor cells disseminate in various distant organs at early stages of cancer progression. These disseminated tumor cells (DTCs) can stay dormant/quiescent without causing patient symptoms for years or decades. These dormant tumor cells survive despite curative treatments by entering growth arrest, escaping immune surveillance, and/or developing drug resistance. However, these dormant cells can reactivate to proliferate, causing metastatic progression and/or relapse, posing a threat to patients' survival. It's unclear how cancer cells maintain dormancy and what triggers their reactivation. What are better approaches to prevent metastatic progression and relapse through harnessing cancer dormancy? To answer these remaining questions, we reviewed the studies of tumor dormancy and reactivation in various types of cancer using different model systems, including the brief history of dormancy studies, the intrinsic characteristics of dormant cells, and the external cues at the cellular and molecular levels. Furthermore, we discussed future directions in the field and the strategies for manipulating dormancy to prevent metastatic progression and recurrence.

Integrating Prostate-specific Antigen Kinetics into Contemporary Predictive Nomograms of Salvage Radiotherapy After Radical Prostatectomy

BACKGROUND

Salvage radiotherapy (SRT) is an established treatment for men with biochemical recurrence following radical prostatectomy (RP). There are several risk factors associated with adverse outcomes; however, the value of postoperative prostate-specific antigen (PSA) kinetics is less clear in the ultrasensitive PSA era.

OBJECTIVE

To characterize the impact of PSA kinetics on outcomes following SRT and generate nomograms to aid in identifying patients with an increased risk of adverse clinical outcomes.

DESIGN, SETTING, AND PARTICIPANTS

A multi-institutional analysis was conducted of 1005 patients with prostate cancer treated with SRT after RP, with a median follow-up of 5 years.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Variables examined include immediate postoperative PSA, postoperative PSA doubling time (DT), and pre-SRT PSA, in addition to previously identified predictive factors. Multivariable survival analyses were completed using Fine-Gray competing risk regression. Rates of biochemical failure (BF), distant metastasis (DM), and prostate cancer-specific mortality (PCSM) were estimated by the cumulative incidence method. Nomograms were generated from multivariable competing risk regression with bootstrap cross-validation.

RESULTS AND LIMITATIONS

Factors associated with BF after SRT include PSA DT <6 mo, initial postoperative PSA ≥0.2 ng/ml, higher pre-SRT PSA, lack of androgen deprivation therapy, a higher Gleason score (GS), negative margins, seminal vesicle invasion, lack of pelvic nodal radiation, radiation total dose <66 Gy, a longer RP to SRT interval, and older age (p < 0.05 for each). Factors associated with DM include PSA DT <6 mo, pre-SRT PSA, a higher GS, and negative margins. Factors associated with PCSM include PSA DT not calculable or <6 mo and a higher GS. Nomograms were generated to estimate the risks of BF (concordance index [CI] 0.74), DM (CI 0.77), and PCSM (CI 0.77). Limitations include retrospective nature, broad treatment eras, institutional variations, and multiple methods available for the estimation of PSA DT.

CONCLUSIONS

Postoperative PSA kinetics, particularly pre-SRT PSA and PSA DT, are strongly associated with adverse oncologic outcomes following SRT and should be considered in management decisions.

PATIENT SUMMARY

In this report of men with prostate cancer who developed a prostate-specific antigen (PSA) recurrence after prostatectomy, we found that PSA levels after surgery and how quickly a PSA level doubles significantly impact the chance of prostate cancer recurrence after salvage radiation therapy. Based on this information, we created a tool to calculate a man's chance of cancer recurrence after salvage radiation therapy, and these estimations can be used to discuss whether additional treatment with radiation should be considered.

Predictive value of Prostate Specific Antigen variations in the last week of salvage radiotherapy for biochemical recurrence of prostate cancer after surgery: A practical approach

BACKGROUND

About a third of patients who underwent radical prostatectomy for prostate cancer (Pca) develop a biochemical failure (BF) within 10 years from surgery, and about a half of them receive salvage radiation therapy (SRT). Factors to predict risk to relapse after SRT are still lacking. Dynamic models, based on the assessment of changes in Prostate Specific Antigen (PSA) postsurgery seem to show good reliability.

AIMS

The goal of the study was to identify a simple analytical method for the postsalvage radiation therapy biochemical failure (post-SRTBF) prediction before the end of the SRT, regardless of the PSA value at the beginning of the treatment (PSA start), measuring the PSA values at the start and 1 week before the end of SRT.

METHODS

In a series of 83 patients treated with SRT for BF of Pca we measured PSA values at the first day and 1 week before the end of SRT. These values were used to define an analytical method for the post-SRTBF prediction.

RESULTS

PSA value in patients without post-SRTBF show a significant difference in term of difference during the SRT with respect to patients with post-SRTBF. Starting from this difference, we identified a simple and practical analytical method for the post-SRTBF prediction before the end of the SRT. The data corresponds with the model and the analytical method is highly predictive (Sensitivity = 81%, Specificity = 85%, Accuracy = 83%).

CONCLUSION

This study offers a new tool to early predict Pca relapse overtime and to select patients who can benefit from an early additional systemic treatment.

Salvage Radiotherapy for Prostate Cancer

For patients experiencing biochemical recurrence in the absence of distant metastasis, salvage radiotherapy (SRT) with or without androgen deprivation therapy (ADT) is currently the only possible curative treatment option. Prostate-specific antigen (PSA) monitoring and the selected use of SRT has some advantages when compared with adjuvant radiotherapy. The most important one is avoidance of a potential overtreatment of patients who would never have disease progression, even in the presence of high-risk pathological features. The identification of a specific PSA cut-off seems to be incorrect. In patients with more adverse pathological features, early SRT administered at the very first sign of a PSA rise granted better disease control. Dose-intensified SRT is feasible and well tolerated with no significant difference in grade 2 or more acute and late toxicity. At least 66 Gy must be given in the salvage setting. ADT has a radio-sensitising effect on the radiotherapy by inhibiting the repair of DNA double-strand breaks. The use of ADT in the salvage setting results in a better oncological outcome. Hormonal therapy is associated with a decrease in quality of life and side-effects depending on the duration of hormone therapy. The oncological benefit of hormone therapy duration depends on their clinical and pathological characteristics. 68-Ga-prostate-specific membrane antigen positron emission tomography-computed tomography is the gold standard in staging prostate cancer patients with biochemical persistence or recurrence after radical prostatectomy. The implementation of 18F-labelled PSMA tracers can provide a further improvement.

Long- versus short-term androgen deprivation therapy with high-dose radiotherapy for biochemical failure after radical prostatectomy: a randomized controlled trial

Radical prostatectomy is a well-established treatment option in the management of localized and locally advanced prostate cancer. An extended lymphadenectomy is performed in case of substantial risk for lymph node involvement. When biochemical recurrence (BCR) occurs, salvage radiotherapy (SRT) is performed. The benefit in terms of BCR-free survival (FS) and metastasis-FS by adding 6 months of androgen deprivation therapy (ADT) compared with SRT only has already been established. Retrospective evidence suggests that a longer schedule of ADT may be more beneficial compared with 6 months. This multicenter open-label randomized trial will include patients who need SRT after experiencing BCR post-radical prostatectomy with lymphadenectomy and pN0-status. Patients will be randomized for ADT duration (6 vs 24 months). Primary end point is distant metastasis-FS.

Clinical Trial Registration: NCT04242017 ( ClinicalTrials.gov )

Evaluation of an Online Education Resource on Radiation Therapy Created for Patients with Postprostatectomy Prostate Cancer and Their Caregivers

INTRODUCTION

Radiation therapy (RT) after prostatectomy is an important curative treatment option for patients with prostate cancer. It can be delivered immediately after surgery as adjuvant treatment, or after biochemical PSA failure as salvage treatment. There is currently a lack of consensus regarding whether salvage RT in the event of biochemical failure or immediate adjuvant RT is the optimal postprostatectomy RT treatment. Although both types of postprostatectomy RT are generally well tolerated, patients may develop some toxicity that can impact their quality of life and the duration and frequency of treatments can be challenging for patients. It is imperative that patients be provided with evidence-based information so that they are able to make a treatment decision most aligned with their values.

METHODS

To help address patients' informational needs, an online education resource was created for patients with prostate cancer considering postoperative RT. Patients and their families were asked to evaluate the effectiveness of this resource using a validated purpose-based information assessment.

RESULTS

Nineteen patients were approached and 14 participated, but only five patients returned their evaluations (35%). Sixty percent found the information to be important with regards to each of the six commonly identified purposes in the purpose-based information assessment: organizing, understanding, decision-making, planning, emotional support, and discussing. Only one participant found the information hard to understand and had difficulty finding specific information.

DISCUSSION

Patients should be encouraged to actively participate in their treatment decision-making process involving postprostatectomy RT. For patients to make well-informed decisions, patients must be provided with clear and accessible information so that they may understand their disease and the treatment options.

CONCLUSION

An online education resource has been developed that most study respondents found clear and helpful for a variety of identified purposes. Overall, this online education resource has the potential to reach a large number of patients and their caregivers who desire specific information and involvement in future treatment decisions.

Optimizing the Timing of Salvage Postprostatectomy Radiotherapy and the Use of Concurrent Hormonal Therapy for Prostate Cancer

CONTEXT

Currently, salvage radiotherapy (SRT) is the only known curative intervention for men with recurrent disease following prostatectomy. Critical issues in the optimal selection and management of men being considered for SRT include the threshold prostate-specific antigen (PSA) value at which to initiate treatment (ie, pre-SRT PSA) and the role of concurrent hormonal therapy (HT).

OBJECTIVE

To review the published evidence pertaining to the optimal timing for SRT and the role of concurrent HT.

EVIDENCE ACQUISITION

MEDLINE (via PubMed), EMBASE, the Cochrane Central Register of Controlled Trials, and guideline statements from professional organizations were queried from January 1, 2000 through January 10, 2018.

EVIDENCE SYNTHESIS

Thirty-three independent reports, including two randomized trials evaluating HT with SRT, were identified. Retrospective data suggest that SRT initiation at lower pre-SRT PSA levels is associated with better clinical outcomes. Prospective data suggest an overall survival benefit with concurrent HT that manifests during long-term follow-up, with the caveat that hypothesis-generating subgroup analyses suggest that this benefit may be limited to patients with higher pre-SRT PSA levels. Patients with adverse risk factors, such as Gleason grade group 4-5 disease, are likely to benefit the most from earlier SRT initiation and/or the use of HT.

CONCLUSIONS

Given the limitations of the available data, it is imperative that physicians participate in shared decision-making, with the recommendation tailored for each man's desire to maximize oncologic benefit (with a risk of overtreatment) versus potential quality-of-life optimization (with a risk of undertreatment). Within that framework, a significant body of retrospective data supports initiation of SRT at low pre-SRT PSA values, without an arbitrary absolute threshold. Prospective data suggest a benefit of HT, but this benefit may be greatest in patients with a pre-SRT PSA that is higher than the typical level in most patients receiving "early" SRT. Further research is necessary before absolute recommendations can be made.

PATIENT SUMMARY

Two ways to potentially improve outcomes following salvage radiotherapy for prostate cancer that recurs after prostatectomy are to start treatment at a lower prostate-specific antigen level and to use concurrent hormonal therapy. Our review suggests that the available evidence is imperfect, but highlights that both measures are likely to improve clinical outcomes in general, but perhaps not uniformly and/or consistently for all patients. Physician-patient shared decision-making and further research are critical.

Comparison Between Adjuvant and Early-Salvage Postprostatectomy Radiotherapy for Prostate Cancer With Adverse Pathological Features

Importance

Prostate cancer with adverse pathological features (ie, pT3 and/or positive margins) after prostatectomy may be managed with adjuvant radiotherapy (ART) or surveillance followed by early-salvage radiotherapy (ESRT) for biochemical recurrence. The optimal timing of postoperative radiotherapy is unclear.

Objective

To compare the clinical outcomes of postoperative ART and ESRT administered to patients with prostate cancer with adverse pathological features.

Design, Setting, and Participants

This multi-institutional, propensity score-matched cohort study involved 1566 consecutive patients who underwent postprostatectomy ART or ESRT at 10 US academic medical centers between January 1, 1987, and December 31, 2013. Propensity score 1-to-1 matching was used to account for covariates potentially associated with treatment selection. Data were collected from January 1 to September 30, 2016. Data analysis was conducted from October 1, 2016, to October 21, 2017.

Main Outcomes and Measures

Freedom from postirradiation biochemical failure, freedom from distant metastases, and overall survival. All outcomes were measured from date of surgery to address lead-time bias.

Results

Of 1566 patients, 1195 with prostate-specific antigen levels of 0.1 to 0.5 ng/mL received ESRT and 371 patients with prostate-specific antigen levels lower than 0.1 ng/mL received ART. The median age (interquartile range) was 60 (55-65) years. After propensity score matching, the median (interquartile range) follow-up after surgery was similar between the ESRT and ART groups (73.3 [44.9-106.6] months vs 65.8 [40-107] months; P = .22). Adjuvant RT, compared with ESRT, was associated with higher freedom from biochemical failure (12-year actuarial rates: 69% [95% CI, 60%-76%] vs 43% [95% CI, 35%-51%]; effect size, 26%), freedom from distant metastases (95% [95% CI, 90%-97%] vs 85% [95% CI, 76%-90%]; effect size, 10%), and overall survival (91% [95% CI, 84%-95%] vs 79% [95% CI, 69%-86%]; effect size, 12%). Adjuvant RT, lower Gleason score and T stage, nodal irradiation, and postoperative androgen deprivation therapy were favorable prognostic features on multivariate analysis for biochemical failure. Sensitivity analysis demonstrated that the decreased risk of biochemical failure associated with ART remained significant unless more than 56% of patients in the ART group were cured by surgery alone. This threshold is greater than the estimated 12-year freedom from biochemical failure rate of 33% to 52% after radical prostatectomy alone, as determined by a contemporary dynamic nomogram.

Conclusions and Relevance

Adjuvant RT, compared with ESRT, was associated with reduced biochemical recurrence, distant metastases, and death for high-risk patients, pending prospective validation. These findings suggest that a greater proportion of patients with prostate cancer who have adverse pathological features may benefit from postprostatectomy ART rather than surveillance followed by ESRT.

The impact of the definition of biochemical recurrence following salvage radiotherapy on outcomes and prognostication in patients with recurrent prostate cancer after radical prostatectomy: a comparative study of three definitions

Purpose

The clinical management and follow-up of patients with recurrent prostate cancer after salvage radiotherapy (SRT) has not yet been established, and no standardized definition of biochemical recurrence (BCR) after SRT exists. We compared the impact of applying three different definitions of BCR following SRT on patient outcomes and prognostication.

Subjects

Patients who received salvage androgen-deprivation therapy before the completion of SRT were excluded. The data of 118 men who had undergone salvage radiation as monotherapy for BCR after radical prostatectomy were reviewed. In all patients, SRT comprised irradiation to the prostatic bed (70 Gy) using three-dimensional conformal radiotherapy techniques. Treatment outcomes, including BCR-free survival and prognostic factors, were analyzed and compared among three definitions: The Nara, Radiation Therapy Oncology Group (RTOG) 9601, and GETUG-AFU 16 definitions.

Results

The BCR rate differed significantly among the applied definitions. Multivariate analyses identified the same four independent prognostic factors, including primary Gleason pattern 4 or 5, negative resection margin, prostate-specific antigen (PSA) level before SRT 0.5 or more, and PSA doubling time before SRT <6 months, using the RTOG 9601 and GETUG-AFU 16 definitions, whereas only two of the four factors were identified using the Nara definition. Although the results obtained using the RTOG 9601 and GETUG-AFU 16 definitions were similar, the prognostic value of the four factors differed. According to the RTOG 9601 definition of BCR, a negative resection margin on prostatectomy specimens and short PSA doubling time before SRT were associated with no subsequent response in PSA level.

Conclusions

The applied definition of BCR after SRT can influence the reported BCR-free rate and the potential prognostic factors. Establishment of the standardized definition is needed for the optimal management of patients with recurrent prostate cancer undergoing SRT.

Improved Metastasis-Free and Survival Outcomes With Early Salvage Radiotherapy in Men With Detectable Prostate-Specific Antigen After Prostatectomy for Prostate Cancer

Purpose To describe outcomes of salvage radiotherapy (SRT) for men with detectable prostate-specific antigen (PSA) after radical prostatectomy for prostate cancer and identify associations with outcomes. Patients and Methods A total of 1,106 patients received SRT between January 1987 and July 2013, with median follow-up 8.9 years. Outcomes were estimated using Kaplan-Meier for overall survival (OS) and cumulative incidence for biochemical recurrence (BcR), distant metastases (DM), and cause-specific mortality (CSM). Variable associations with outcomes used Cox or Fine-Gray methods, as appropriate. Multiple variable analyses used backward selection with P < .05 for retention. Results In multiple variable analyses, pathologic tumor stage, Gleason score, and pre-SRT PSA were associated with BcR, DM, CSM, and OS; androgen suppression and SRT doses > 68 Gy were associated with BcR; and age was associated with OS. Each pre-SRT PSA doubling increased significantly the relative risk of BcR (hazard ratio [HR], 1.30; P < .001), DM (HR, 1.32; P < .001), CSM (HR, 1.40; P < .001), and all-cause mortality (HR, 1.12; P = .02). Using a pre-SRT PSA cutoff ≤ 0.5 versus > 0.5 ng/mL, 5-year and 10-year cumulative incidences for BcR were 42% versus 56% and 60% versus 68% ( P < .001), DM 7% versus 14% and 13% versus 25% ( P < .001), CSM 1% versus 4% and 6% versus 13% ( P < .001), and OS of 94% versus 92% and 83% versus 73% ( P > .05). Conclusion SRT outcomes are in part affected by factors associated with prostatectomy findings but may be positively affected by using SRT at lower PSA levels, including reductions in BcR, DM, CSM, and all-cause mortality. These findings argue against prolonged monitoring of detectable postprostatectomy PSA levels that delay initiation of SRT.

Drug development for noncastrate prostate cancer in a changed therapeutic landscape

The unprecedented progress in the treatment of metastatic castration-resistant prostate cancer is only beginning to be realized in patients with noncastrate disease. This slow progress in part reflects the use of trial objectives focused on time-to-event end points, such as time to metastasis and overall survival, which require long follow-up durations and large sample sizes, and has been further delayed by the use of approved therapies that are effective at the time of progression. Our central hypotheses are that progress can be accelerated, and that outcomes can be improved by shifting trial objectives to response measures occurring early that solely reflect the effects of the treatment. To test these hypotheses, a continuously enrolling multi-arm, multi-stage randomized trial design, analogous to that used in the STAMPEDE trial, has been developed. Eligibility is focused on patients with incurable disease or those with a high risk of death with any form of monotherapy alone. The primary objective is to eliminate all disease using a multimodality treatment strategy. End points include pathological complete response and an undetectable level of serum prostate-specific antigen, with recovery of serum testosterone levels. Both are binary, objective, and provide an early, quantitative indication of efficacy.

Post-prostatectomy radiation therapy for locally recurrent prostate cancer

INTRODUCTION

Approximately 15-30% of men with localized prostate cancer will experience biochemical recurrence (BCR) after radical prostatectomy. Postoperative radiation therapy is used in men with adverse pathological features to reduce the risk of BCR or with curative intent in men with known BCR. In this study, we review the evidence for the adjuvant and salvage radiation therapy after radical prostatectomy. Areas covered: A literature review of the Medline and Embase databases was performed. The search strategy included the following terms: prostate cancer, adjuvant radiotherapy, salvage radiotherapy, radical prostatectomy, biochemical recurrence, and prostate cancer recurrence. Prospective randomized trials for the adjuvant radiotherapy and observational studies supporting salvage radiotherapy were included for discussion. Expert commentary: As postoperative radiotherapy is associated with non-trivial risks of acute and long-term toxicity and given the absence of compelling data supporting adjuvant over early salvage radiotherapy, the authors advocate, with rare exceptions, close observation and timely (early) salvage radiotherapy for patients with BCR and long life expectancy. Adjuvant radiotherapy may be considered in patients at high-risk for recurrence. Observation is appropriate in patients with limited life expectancy and/or absence of adverse features.

Impact of Early Salvage Radiation Therapy in Patients with Persistently Elevated or Rising Prostate-specific Antigen After Radical Prostatectomy

BACKGROUND

Salvage radiation therapy (SRT) is a recommended treatment option for biochemical recurrence after radical prostatectomy (RP). However, its effectiveness may be limited to specific categories of patients.

OBJECTIVE

We aimed to identify the optimal candidates for early SRT after RP.

DESIGN, SETTING, AND PARTICIPANTS

The study included 925 node-negative patients treated with SRT after RP at seven institutions. Patients received SRT for either prostate-specific antigen (PSA) rising, or PSA persistence after RP that was defined as PSA level ≥0.1 ng/ml at 1 mo after surgery. All patients received local radiation to the prostate and seminal vesicle bed.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary outcome measured was distant metastasis after SRT. Regression tree analysis was used to develop a risk-stratification tool. Multivariable Cox regression analysis and nonparametric curve fitting methods were used to explore the relationship between PSA level at SRT and the probability of metastasis-free survival at 8 yr.

RESULTS AND LIMITATIONS

At a median follow-up of 8.0 yr, 130 patients developed distant metastasis. At multivariable analysis, pre-SRT PSA level was significantly associated with distant metastasis (hazard ratio: 1.06, p<0.0001). However, when patients were stratified into five risk groups using regression tree analysis (area under the curve: 85%), early SRT administration provided better metastasis-free survival in three groups only: (1) low risk: undetectable PSA after RP, Gleason score ≤7, and tumour stage ≥pT3b, (2) intermediate risk: undetectable PSA after RP with Gleason score ≥8, (3) high risk: PSA persistence after RP with Gleason score ≤7.

CONCLUSIONS

We developed an accurate risk stratification tool to facilitate the individualised recommendation for early SRT based on prostate cancer characteristics. Early SRT proved to be beneficial only in selected groups of patients who are more likely to be affected by clinically significant but not yet systemic recurrence at the time of salvage treatment administration.

PATIENT SUMMARY

In patients affected by prostate cancer recurrence after radical prostatectomy, the early administration of salvage radiation therapy is beneficial only for selected subgroups of patients. In this study, these groups of patients were identified.

Defining biochemical recurrence after radical prostatectomy and timing of early salvage radiotherapy : Informing the debate

BACKGROUND

The optimal prostate-specific antigen (PSA) level after radical prostatectomy (RP) for defining biochemical recurrence and initiating salvage radiation therapy (SRT) is still debatable. Whereas adjuvant or extremely early SRT irrespective of PSA progression might be overtreatment for some patients, SRT at PSA >0.2 ng/ml might be undertreatment for others. The current study addresses the optimal timing of radiation therapy after RP.

PATIENTS AND METHODS

Cohort 1 comprised 293 men with PSA 0.1-0.19 ng/ml after RP. Cohort 2 comprised 198 men with SRT. PSA progression and metastases were assessed in cohort 1. In cohort 2, we compared freedom from progression according to pre-SRT PSA (0.03-0.19 vs. 0.2-0.499 ng/ml). Multivariable Cox regression analyses predicted progression after SRT.

RESULTS

In cohort 1, 281 (95.9%) men had further PSA progression ≥0.2 ng/ml and 27 (9.2%) men developed metastases within a median follow-up of 74.3 months. In cohort 2, we recorded improved freedom from progression according to lower pre-SRT PSA (0.03-0.19 vs. 0.2-0.499 ng/ml: 69 vs. 53%; log-rank p = 0.051). Patients with higher pre-SRT PSA ≥0.2 ng/ml were at a higher risk of progression after SRT (hazard ratio: 1.8; p < 0.05).

CONCLUSION

The vast majority of patients with PSA ≥0.1 ng/ml after RP will progress to PSA ≥0.2 ng/ml. Additionally, early administration of SRT at post-RP PSA level <0.2 ng/ml might improve freedom from progression. Consequently, we suggest a PSA threshold of 0.1 ng/ml to define biochemical recurrence after RP.

Long-term results of adjuvant versus early salvage postprostatectomy radiation: A large single-institutional experience

PURPOSE

The purpose of this study was to evaluate freedom from biochemical failure (FFBF), freedom from androgen deprivation therapy (FFADT), freedom from distant metastases (FFDM), and overall survival (OS) after adjuvant radiation therapy (ART) versus early salvage radiation therapy (ESRT) in men with prostate cancer and adverse pathologic features (pT3 and/or positive surgical margins).

METHODS AND MATERIALS

Of 718 patients consecutively treated with postoperative radiation therapy (RT) for prostate cancer between 1992 and 2013, we retrospectively identified 171 men receiving ART and 230 receiving ESRT (RT delivered at a prostate-specific antigen level ≤0.5 ng/mL) who had adverse pathologic features. Postirradiation FFBF (BF was defined as prostate-specific antigen level rise to ≥0.2 ng/mL), FFADT, FFDM, and OS were compared using Kaplan-Meier and Cox regression methods. Propensity score (PS)-matching was performed to estimate treatment effects while accounting for covariates predicting treatment allocation.

RESULTS

Median follow-up was 7.4 and 8.0 years for patients treated with ART and ESRT, respectively. Ten-year FFBF (69% vs 56%, P = .003) and 10-year FFADT (88% vs 81%, P = .046) rates were higher after ART; however, FFDM and OS did not significantly differ. After PS-matching, ART was associated with improved FFBF (P < .0001), FFADT (P = .0001), and FFDM (P = .02). Findings were confirmed in multivariable analyses in unmatched and PS-matched cohorts. Sensitivity analyses showed that FFBF benefit associated with ART lost statistical significance only after 38% of ART patients were assumed to have been cured by surgery and excluded from the model. This corresponds to the upper bound of patients with adverse pathologic features who did not recur after observation in prior randomized trials.

CONCLUSIONS

Postoperative RT confers excellent long-term cancer control. These results suggest ART may be associated with improved FFBF, FFADT, and FFDM, but comparable OS. Given the retrospective study design, these findings should be interpreted with caution. Optimal timing of postoperative RT further awaits results of ongoing trials.

Contemporary Mapping of Post-Prostatectomy Prostate Cancer Relapse with 11C-Choline Positron Emission Tomography and Multiparametric Magnetic Resonance Imaging

PURPOSE

We identify sites and patterns of cancer recurrence in patients with post-prostatectomy biochemical relapse using ¹¹C-choline positron emission tomography/computerized tomography and endorectal coil multiparametric magnetic resonance imaging.

MATERIALS AND METHODS

Between January 2008 and June 2015, 2,466 men underwent choline positron emission tomography for suspected prostate cancer relapse at our institution. Of these men 202 did not receive hormone or radiation therapy, underwent imaging with choline positron emission tomography and multiparametric magnetic resonance imaging, and were found to have disease recurrence. Overall patterns of recurrence were described, and factors associated with local only recurrence were evaluated using univariable and multivariable logistic regression.

RESULTS

Median prostate specific antigen at positive scan was 2.3 ng/ml (IQR 1.4-5.5) with a median time from prostate specific antigen relapse to lesion visualization of 15 months (IQR 4.8-34.2). Of these 202 men 68 (33%) exhibited local only, 45 (22%) local plus metastatic and 89 (45%) metastatic only relapse. Pelvic node only relapse was observed in 39 (19%) men. Median prostate specific antigen at positive imaging for patients with local only, metastatic only and local plus metastatic relapse was 2.3, 2.7 and 2.2 ng/ml (p=0.46), with a median interval from biochemical recurrence to positive scan of 33.5, 7.0 and 15.0 months, respectively (p <0.001). On multivariable analysis time from biochemical recurrence to positive imaging was independently associated with local only recurrence (OR 1.10 for every 6-month increase, p=0.012).

CONCLUSIONS

Combined choline positron emission tomography and multiparametric magnetic resonance imaging evaluation of biochemical recurrence after prostatectomy reveals an anatomically diverse pattern of recurrence. These findings have implications for optimizing the salvage treatment of patients with prostate cancer with relapse following surgery.

Radiation Therapy after Radical Prostatectomy: Implications for Clinicians

Depending on the pathological findings, up to 60% of prostate cancer patients who undergo radical prostatectomy (RP) will develop biochemical relapse and require further local treatment. Radiotherapy (RT) immediately after RP may potentially eradicate any residual localized microscopic disease in the prostate bed, and it is associated with improved biochemical, clinical progression-free survival, and overall survival in patients with high-risk pathological features according to published randomized trials. Offering immediate adjuvant RT to all men with high-risk pathological factors we are over-treating around 50% of patients who would anyway be cancer-free, exposing them to unnecessary toxicity and adding costs to the health-care system. The current dilemma is, thus, whether to deliver adjuvant immediate RT solely on the basis of high-risk pathology, but in the absence of measurable prostate-specific antigen, or whether early salvage radiotherapy would yield equivalent outcomes. Randomized trials are ongoing to definitely answer this question. Retrospective analyses suggest that there is a dose–response favoring doses >70 Gy to the prostate bed. The evidence regarding the role of androgen deprivation therapy is emerging, and ongoing randomized trials are underway.

Salvage radiation therapy following radical prostatectomy. A national Danish study

BACKGROUND

The purpose of this observational cohort study was to evaluate the outcome and prognostic factors following salvage radiotherapy (SRT) in a consecutive national cohort.

MATERIAL AND METHODS

Between 2006 and 2010, 259 patients received SRT in Denmark. Patient- and cancer-related characteristics were retrospectively retrieved from patient charts. The primary end point was biochemical progression-free survival (b-PFS).

RESULTS

At the end of follow-up, 51% of the patients displayed a prostate-specific antigen (PSA) level <0.1 ng/ml. The three-year b-PFS rate for the total cohort was 57.0%. Nearly half of the patients (44%) received androgen deprivation therapy (ADT) in combination with SRT. Positive surgical tumour margins (p = 0.025) and ADT (p = 0.001) were the only markers independently correlated with b-PFS. In patients who received SRT without ADT, both a pre-SRT PSA level ≤0.5 ng/ml (p = 0.003) and pathological tumour stage T1-T2 (p = 0.036) independently correlated with b-PFS. Moreover, a duration between radical prostatectomy (RP) and SRT ≤29 months (p = 0.035) independently correlated with b-PFS in patients treated with ADT in combination with RT.

CONCLUSIONS

In patients treated for biochemical failure after RP, positive surgical tumour margins and PSA levels ≤0.5 ng/mL at the time of SRT were associated with a favourable outcome. Despite less favourable tumour characteristics, patients receiving SRT and ADT demonstrated improved b-PFS, and in particular, patients with PSA levels >0.2 ng/ml benefitted from additional ADT.

An Examination of the Association between FOXA1 Staining Level and Biochemical Recurrence following Salvage Radiation Therapy for Recurrent Prostate Cancer

BACKGROUND

Standardly collected clinical and pathological patient information has demonstrated only moderate ability to predict risk of biochemical recurrence (BCR) of prostate cancer in men undergoing salvage radiation therapy (SRT) for a rising PSA after radical prostatectomy (RP). Although elevated FOXA1 staining has been associated with poor patient outcomes following RP, it has not been studied in the specific setting of SRT after RP. The aim of this study was to evaluate the association between FOXA1 staining level and BCR after SRT for recurrent prostate cancer.

METHODS

A total of 141 men who underwent SRT at our institution were included. FOXA1 staining levels in primary tumor samples were detected using immunohistochemistry. FOXA1 staining percentage and intensity were measured and multiplied together to obtain a FOXA1 H-score (range 0-12) which was our primary staining measure. P-values ≤ 0.0056 were considered as statistically significant after applying a Bonferroni correction for multiple comparisons.

RESULTS

There was not a significant association between FOXA1 H-score and risk of BCR when considering H-score as an ordinal variable or as a categorical variable (all P ≥ 0.090). Similarly, no significant associations with BCR were observed for FOXA1 staining percentage or staining intensity (all P ≥ 0.14).

CONCLUSIONS

FOXA1 staining level does not appear to have a major impact on risk of BCR after SRT.

Assessing the Optimal Timing for Early Salvage Radiation Therapy in Patients with Prostate-specific Antigen Rise After Radical Prostatectomy

BACKGROUND

Early salvage radiation therapy (eSRT) represents a treatment option for patients who experience a prostate-specific antigen (PSA) rise after radical prostatectomy (RP); however, the optimal PSA level for eSRT administration is still unclear.

OBJECTIVE

To test the impact of PSA level on cancer control after eSRT according to pathologic tumour characteristics.

DESIGN, SETTING, AND PARTICIPANTS

The study included 716 node-negative patients with undetectable postoperative PSA who experienced a PSA rise after RP. All patients received eSRT, defined as local radiation to the prostate and seminal vesicle bed, delivered at PSA ≤ 0.5 ng/ml. Biochemical recurrence (BCR) after eSRT was defined as two consecutive PSA values ≥ 0.2 ng/ml.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Multivariable Cox regression analysis tested the association between pre-eSRT PSA level and BCR after eSRT. Covariates consisted of pathologic stage (pT2 vs pT3a vs pT3b or higher), pathologic Gleason score (≤ 6, 7, or ≥ 8), and surgical margin status (negative vs positive). We tested an interaction with PSA level and baseline pathologic risk for the hypothesis that BCR-free survival differed by pre-eSRT PSA level. Three pathologic risk factors were identified: pathologic stage pT3b or higher, pathologic Gleason score ≥ 8, and negative surgical margins.

RESULTS AND LIMITATIONS

Median follow-up among patients who did not experience BCR after eSRT was 57 mo (interquartile range: 27-105). At 5 yr after eSRT, BCR-free survival rate was 82% (95% confidence interval [CI], 78-85). At multivariable Cox regression analysis, pre-eSRT PSA level was significantly associated with BCR after eSRT (hazard ratio: 4.89; 95% CI, 1.40-22.9; p < 0.0001). When patients were stratified according to the number of risk factors at final pathology, patients with at least two pathologic risk factors showed an increased risk of 5-yr BCR as high as 10% per 0.1 ng/ml of PSA level compared with only 1.5% in patients with one or no pathologic risk factors.

CONCLUSIONS

In this retrospective study, cancer control after eSRT greatly depended on pretreatment PSA. The absolute PSA level had a different prognostic value depending on the pathologic characteristics of the tumour. In patients with more adverse pathologic features, eSRT conferred better cancer control when administered at the very first sign of PSA rise. Conversely, the benefit of eSRT was less evident in men with favourable disease at RP.

PATIENT SUMMARY

In this retrospective study, cancer control after early salvage radiation therapy (eSRT) was influenced by pretreatment prostate-specific antigen (PSA) level. This effect was highest in men with at least two of the following pathologic features: pT3b/pT4 disease, pathologic Gleason score ≥ 8, and negative surgical margins. In these patients, eSRT conferred better cancer control when administered at the very first sign of PSA rise.

Preclinical Evaluation of Intraoperative Low-Energy Photon Radiotherapy Using Spherical Applicators in Locally Advanced Prostate Cancer

Background

Surgery plus adjuvant radiotherapy is standard care for locally advanced prostate cancer (stage pT3R1). Intraoperative low-energy photon radiotherapy offers several advantages over external beam radiotherapy, and several systems are now available for its delivery, using spherical applicators, which require only limited shielding. The aim of this study was to evaluate the feasibility of this technique for the prostate bed.

Materials and methods

Applicators were assessed using MRI image data and cadaveric dissection. In cadavers, targeted tissues, defined as a urethral section, both neurovascular bundle sections, the bladder neck and the beds of the seminal vesicles, were marked with metallic surgical clips. Distances between clips and applicator were measured using CT. A dosimetric study of the application of 12 Gy at 5 mm depth was performed using CT images of prostatectomized cadavers.

Results

Using MRI images from 34 prostate cancer patients, we showed that the ideal applicator diameter ranges from 45 to 70 mm. Using applicators of different sizes to encompass the prostate bed in nine cadavers, we showed that the distance between target tissues and applicator was <2 mm for all target tissues except the upper extremity of the seminal vesicles (19 mm). Dosimetric study showed a good dose distribution in all target tissues in contact with the applicator, with a low probability of rectum and bladder complication.

Conclusion

Intraoperative radiotherapy of the prostate bed is feasible, with good coverage of targeted tissues. Clinical study of safety and efficacy is now required.

The significance of circulating tumor cells in prostate cancer patients undergoing adjuvant or salvage radiation therapy

Background:

Following radical prostatectomy, success of adjuvant and salvage radiation therapy (RT) is dependent on the absence of micrometastatic disease. However, reliable prognostic/predictive factors for determining this are lacking. Therefore, novel biomarkers are needed to assist with clinical decision-making in this setting. Enumeration of circulating tumor cells (CTCs) using the regulatory-approved CellSearch System (CSS) is prognostic in metastatic prostate cancer. We hypothesize that CTCs may also be prognostic in the post-prostatectomy setting.

Methods:

Patient blood samples (n=55) were processed on the CSS to enumerate CTCs at 0, 6, 12 and 24 months after completion of RT. CTC values were correlated with predictive/prognostic factors and progression-free survival.

Results:

CTC status (presence/absence) correlated significantly with positive margins (increased likelihood of CTC^neg disease; P=0.032), and trended toward significance with the presence of seminal vesicle invasion (CTC^pos; P=0.113) and extracapsular extension (CTC^neg; P=0.116). Although there was a trend toward a decreased time to biochemical failure (BCF) in baseline CTC-positive patients (n=9), this trend was not significant (hazard ratio (HR)=0.3505; P=0.166). However, CTC-positive status at any point (n=16) predicted for time to BCF (HR=0.2868; P=0.0437).

Conclusions:

One caveat of this study is the small sample size utilized (n=55) and the low number of patients with CTC-positive disease (n=16). However, our results suggest that CTCs may be indicative of disseminated disease and assessment of CTCs during RT may be helpful in clinical decision-making to determine, which patients may benefit from RT versus those who may benefit more from systemic treatments.

Proposed salvage treatment strategy for biochemical failure after radical prostatectomy in patients with prostate cancer: a retrospective study

BACKGROUND

Treatment options for patients with recurrent disease after radical prostatectomy include salvage radiotherapy of the prostatic bed and/or androgen deprivation therapy. To establish an effective treatment strategy for recurrent disease after radical prostatectomy, we retrospectively analyzed the outcome of salvage radiation monotherapy in such cases.

METHODS

Data from 61 men who had undergone salvage radiation monotherapy for biochemical recurrent disease after radical prostatectomy were retrospectively reviewed. In all patients, salvage radiotherapy consisted of iraradiation to the prostatic bed (70 Gy) using three-dimensional conformal radiotherapy techniques. Treatment outcome was analyzed to identify predictive factors of salvage radiotherapy.

RESULTS

The biochemical recurrence-free survival after salvage radiation monotherapy at 2 and 5 years was 55% and 38%, respectively. Cox proportional regression models revealed that the independent predictive factors for biochemical recurrence were Gleason Score ≥ 8, negative surgical margin, and PSA velocity ≥ 0.38 ng/mL/year. Negative surgical margin and PSA velocity ≥ 0.8 ng/mL/year were significantly associated with poor response in the serum PSA levels after salvage radiotherapy.

CONCLUSIONS

Based on our findings, we propose a treatment strategy for biochemical recurrent disease after radical prostatectomy. Patients with Gleason score ≤ 7, positive surgical margin, and PSA velocity < 0.38 ng/mL/year are categorized the most favorable group, so that eradication by salvage radiation monotherapy could be expected. Other patients could be divided to two groups depending on surgical margin status and PSA velocity: 1) patients who might require combination of SRT and short-term androgen deprivation therapy and 2) patients who should be treated by androgen deprivation monotherapy.

Salvage radiotherapy after radical prostatectomy: prediction of biochemical outcomes

Introduction

A significant proportion of patients undergoing salvage radiotherapy (RT) for biochemical recurrence (BCR) following radical prostatectomy (RP) may again experience BCR after salvage RT. Thus, we evaluated the clinical significances of different parameters on the biochemical outcome of RT in salvage setting.

Methods

We reviewed the records of 212 patients who underwent salvage RT between November 2003 and December 2012 for BCR following primary RP. BCR-free survivals after salvage RT were estimated using the Kaplan–Meier method. Cox proportional hazard regression models were used to evaluate the impacts of clinicopathologic parameters on BCR following salvage RT.

Results

The overall median follow-up duration was 63.5 months. The BCR-free survival rate after salvage RT was 58.2% at 5 years. Multivariate analysis showed that a pre-RT prostate-specific antigen (PSA) level of ≤0.5 ng/mL, a pre-RT PSA doubling time (PSADT) of >4.5 months, concomitant androgen deprivation therapy (ADT) with salvage RT, and a positive surgical margin were independent predictors of favorable biochemical outcomes after salvage RT (hazard ratios [HR] = 3.012, 1.132, 2.000, and 1.805, respectively, p = less than 0.001, 0.013, 0.005, and 0.036, respectively). In the early (pre-RT PSA ≤0.5 ng/mL) salvage RT setting, concomitant ADT administration was also shown to be significantly associated with higher risk of BCR-free survival following salvage RT (HR = 2.611, p = 0.038).

Conclusion

Lower pre-RT PSA value, longer PSADT before salvage RT, concomitant ADT administration, and a positive surgical margin were significant predictors of favorable biochemical outcomes following salvage RT performed for BCR after primary RP.

Early biochemical relapse after radical prostatectomy: which prostate cancer patients may benefit from a restaging 11C-Choline PET/CT scan before salvage radiation therapy?

The aim of the study was to assess which factors may influence (11)C-choline PET/CT detection rate in a population of recurrent prostate cancer (PCa) patients listed for salvage radiation therapy (S-RT) in an early phase of biochemical relapse, to select which patients could obtain the most benefit by performing restaging (11)C-choline PET/CT before S-RT.

METHODS

The study comprised 605 patients, treated with radical prostatectomy (RP) with curative intent for PCa who showed rising PSA levels after primary therapy and listed for S-RT. Prostate-specific antigen (PSA) values were >0.2 ng/mL and <2 ng/mL (mean, 1.05 ng/mL; median, 1.07 ng/mL; range, 0.2-2 ng/m; SD, ±0.59). All patients were classified as N0 after RP. Seventeen of 605 patients received adjuvant RT together with RP, whereas 148 of 605 patients received androgen-deprivation therapy (ADT) at the time of PET/CT. PSA, PSA kinetics, Gleason score, age, time to biochemical relapse, ADT, and initial tumor stage were statistically analyzed to assess which factor could influence PET/CT positivity and the detection of local versus distant relapse.

RESULTS

(11)C-choline PET/CT was positive in 28.4% of patients (172/605). Eighty-three of 605 patients were positive in the pelvis (group A), distant metastasis (group B) were detected in 72 of 605 patients, and local and distant sites of relapse were detected in 17 of 605 patients (group C). At multivariate analysis, PSA, PSA doubling time (PSAdt), and ongoing ADT were significant predictors for positive scan results, whereas PSA and PSAdt were significantly related to distant relapse detection (P < 0.05). At the receiver-operating-characteristic analysis, a PSA value of 1.05 ng/mL and PSAdt of 5.95 mo were determined to be the optimal cutoff values in the prediction of a positive (11)C-choline PET/CT scan, with an area under the curve (AUC) of 0.625 for PSA and 0.677 for PSAdt.

CONCLUSION

(11)C-choline PET/CT may be suggested before S-RT during the early phase of biochemical relapse, to select patients who may benefit from this aggressive treatment. Particularly, patients showing fast PSA kinetics or PSA increasing levels despite ongoing ADT should be studied with (11)C-choline PET/CT before S-RT, considering the higher probability to detect positive findings outside the pelvis.

Current trends for the use of androgen deprivation therapy in conjunction with radiotherapy for patients with unfavorable intermediate-risk, high-risk, localized, and locally advanced prostate cancer

Androgen deprivation therapy (ADT) is now a well-established standard of care in combination with definitive radiotherapy for patients with unfavorable intermediate-risk to high-risk locally advanced prostate cancer. It is also well established that combination modality treatment with ADT and radiotherapy is superior to either of these modalities alone for the treatment of patients with high-risk locally advanced disease. Current treatment guidelines for prostate cancer in the United States are based on the estimated risk of recurrence and death. This review examines the clinical evidence underpinning the use of ADT and radiotherapy among patients with high-risk localized and locally advanced disease in the United States. This review also considers the rationale for moving from traditional luteinizing hormone-releasing hormone agonists to more recently developed gonadotrophin-releasing hormone antagonists.

Prediction of outcome following early salvage radiotherapy among patients with biochemical recurrence after radical prostatectomy

BACKGROUND

Early salvage radiotherapy (eSRT) represents the only curative option for prostate cancer patients experiencing biochemical recurrence (BCR) for local recurrence after radical prostatectomy (RP).

OBJECTIVE

To develop and internally validate a novel nomogram predicting BCR after eSRT in patients treated with RP.

DESIGN, SETTING, AND PARTICIPANTS

Using a multi-institutional cohort, 472 node-negative patients who experienced BCR after RP were identified. All patients received eSRT, defined as local radiation to the prostate and seminal vesicle bed, delivered at prostate-specific antigen (PSA) ≤ 0.5 ng/ml.

OUTCOME MEASUREMENT AND STATISTICAL ANALYSIS

BCR after eSRT was defined as two consecutive PSA values ≥ 0.2 ng/ml. Uni- and multivariable Cox regression models predicting BCR after eSRT were fitted. Regression-based coefficients were used to develop a nomogram predicting the risk of 5-yr BCR after eSRT. The discrimination of the nomogram was quantified with the Harrell concordance index and the calibration plot method. Two hundred bootstrap resamples were used for internal validation.

RESULTS AND LIMITATIONS

Mean follow-up was 58 mo (median: 48 mo). Overall, 5-yr BCR-free survival rate after eSRT was 73.4%. In univariable analyses, pathologic stage, Gleason score, and positive surgical margins were associated with the risk of BCR after eSRT (all p ≤ 0.04). These results were confirmed in multivariable analysis, where all the previously mentioned covariates as well as pre-RT PSA were significantly associated with BCR after eSRT (all p ≤ 0.04). A coefficient-based nomogram demonstrated a bootstrap-corrected discrimination of 0.74. Our study is limited by its retrospective nature and use of BCR as an end point.

CONCLUSIONS

eSRT leads to excellent cancer control in patients with BCR for presumed local failure after RP. We developed the first nomogram to predict outcome after eSRT. Our model facilitates risk stratification and patient counselling regarding the use of secondary therapy for individuals experiencing BCR after RP.

PATIENT SUMMARY

Salvage radiotherapy leads to optimal cancer control in patients who experience recurrence after radical prostatectomy. We developed a novel tool to identify the best candidates for salvage treatment and to allow selection of patients to be considered for additional forms of therapy.

Salvage Low-Dose-Rate Brachytherapy for Prostate Cancer Local Recurrence after Radical Prostatectomy: Our First three Patients

Purpose of the Study

To present our initial experience with brachytherapy (BT) as a primary salvage procedure for the treatment of prostate cancer (PCa) local recurrence following radical retropubic prostatectomy (RRP).

Methods

From December 2009 to May 2010, three patients underwent salvage BT due to local recurrences of high risk PCa after extrafascial RRP without additional adjuvant therapies. Local recurrence was confirmed by prostate biopsy and the relapse was well defined by endorectal ultrasonography and magnetic resonance imaging. Metastatic screening was negative. The patients were followed-up according to the American Brachytherapy Society guidelines.

Results

The median dose delivered to 90% of the local relapse (D90) was 115 Gy. The three patients reached a prostate specific antigen (PSA) nadir value within the first year that remained stable at a mean follow-up of 32 months. As regards morbidity, moderate de novo urgency was reported by only one patient.

Conclusions

We think that our data confirms the feasibility and safety of salvage BT as a possible alternative option to external beam radiotherapy (EBRT) for the treatment of locally recurrent PCa in selected patients when performed by experienced centers. However, larger series of patients with longer follow-ups are needed to define the oncologic role of this procedure.

Opinions from the experts: exploring what prostate cancer patients should know about post-operative radiotherapy

The present study investigated health professionals' opinions about important questions that should be discussed with patients who may require post-prostatectomy radiotherapy. A 74-question survey was conducted among radiation oncologists, urologists, nurses, and radiation therapists involved in the care of prostate cancer patients. Survey questions covered six domains: understanding my situation and prostate cancer diagnosis, making a decision, radiotherapy: procedures involved, potential benefits, side effects, and my support network during radiation treatment. Respondents rated the importance of addressing these questions as either essential, important, no opinion, or avoid with a hypothetical post-prostatectomy case. The majority of questions were rated as either essential or important. There was disagreement between professions on essential questions, mostly between nurses and urologists in the side-effects domain. There was agreement between all professions regarding which questions should be avoided.

Gleason pattern 5 is the strongest pathologic predictor of recurrence, metastasis, and prostate cancer-specific death in patients receiving salvage radiation therapy following radical prostatectomy

BACKGROUND

The presence of Gleason pattern 5 (GP5) at radical prostatectomy (RP) has been associated with worse clinical outcome; however, this pathologic variable has not been assessed in patients receiving salvage radiation therapy (SRT) after a rising prostate-specific antigen level.

METHODS

A total of 575 patients who underwent primary RP for localized prostate cancer and subsequently received SRT at a tertiary medical institution were reviewed retrospectively. Primary outcomes of interest were biochemical failure (BF), distant metastasis (DM), and prostate cancer-specific mortality (PCSM), which were assessed via univariate analysis and Fine and Grays competing risks multivariate models.

RESULTS

On pathologic evaluation, 563 (98%) patients had a documented Gleason score (GS). The median follow-up post-SRT was 56.7 months. A total of 60 (10.7%) patients had primary, secondary, or tertiary GP5. On univariate analysis, the presence of GP5 was prognostic for BF (hazard ratio [HR] 3.3; P < .0001), DM (HR:11.1, P < .0001), and PCSM (HR:8.8, P < .0001). Restratification of the Gleason score to include GP5 as a distinct entity resulted in improved prognostic capability. Patients with GP5 had clinically worse outcomes than patients with GS8(4+4). On multivariate analysis, the presence of GP5 was the most adverse pathologic predictor of BF (HR 2.9; P < .0001), DM (HR 14.8; P < .0001), and PCSM (HR 5.7; P < .0001).

CONCLUSION

In the setting of SRT for prostate cancer, the presence of GP5 is a critical pathologic predictor of BF, DM, and PCSM. Traditional GS risk stratification fails to fully utilize the prognostic capabilities of individual Gleason patterns among men receiving SRT post-RP.

Salvage intensity modulated radiotherapy using endorectal balloon after radical prostatectomy: clinical outcomes

OBJECTIVES

To evaluate biochemical non-evidence of disease and adverse events of salvage intensity-modulated radiotherapy using an endorectal balloon for prostate cancer patients after radical prostatectomy.

METHODS

Data of 107 patients (median age 65 years) with persistent (>0.1 ng/mL) or rising prostate-specific antigen after radical prostatectomy were retrospectively analyzed. The mean dose to clinical target volume was 70 Gy in 32 fractions (the equivalent dose in 2 Gy fraction is 73.2 Gy based on α:β = 2). Biochemical non-evidence of disease and predictive factors were assessed. Genitourinary toxicity and gastrointestinal toxicity were also evaluated using the Radiation Therapy Oncology Group toxicity criteria.

RESULTS

The median follow up was 37 months (range 6-126 months). A total of 48 patients developed biochemical recurrence. The 3- and 5-year biochemical non-evidence of disease rates of all patients were 52.6% and 48.8%, respectively. The Gleason score (≥4 + 3, ≤3 + 4) and pre-intensity-modulated radiotherapy prostate-specific antigen level (≥0.5 ng/mL, <0.5 ng/mL) were significant predictive factors for biochemical non-evidence of disease in univariate analysis. In multivariate analysis, only the Gleason score was detected as a significant variable. The highest late genitourinary toxicities were grade 2 in 13% and grade 3 in 6% of patients. The highest late gastrointestinal toxicities were grade 2 in 6% and grade 3 in 3% of patients.

CONCLUSION

Despite a relatively high radiation dose, intensity-modulated radiotherapy with an endorectal balloon can be delivered with acceptable toxicity and efficacy for patients developing biochemical recurrence after radical prostatectomy.

Evaluation of MDM2, p16, and p53 staining levels as biomarkers of biochemical recurrence following salvage radiation therapy for recurrent prostate cancer

BACKGROUND AND PURPOSE

The selection of appropriate candidates for salvage radiation therapy (SRT) to address a rising PSA following radical prostatectomy remains challenging. Herein, we provide the first evaluation of the ability of staining levels of the tumor based biomarkers MDM2, p16, and p53 to aid in prediction of biochemical recurrence (BCR) among men undergoing SRT for recurrent prostate cancer.

MATERIAL AND METHODS

We identified 152 patients who were treated with SRT between July 1987 and July 2003. Staining levels of MDM2, p16, and p53 in primary tumor samples removed during prostatectomy were detected using monoclonal antibodies and quantified by use of a computer-assisted method. Associations of staining levels with BCR were evaluated using Cox proportional hazards regression models; relative risks (RRs) and 95% confidence intervals (CIs) were estimated.

RESULTS

Compared to patients with low staining (≤median) as measured by percentage of cells with nuclear staining, there was no significant difference in risk of BCR for patients with high MDM2 staining (RR: 0.90, 95% CI: 0.57-1.45, P = 0.67), high p16 staining (RR: 0.88, 95% CI: 0.54-1.44, P = 0.62), or high p53 staining (RR: 1.33, 95% CI: 0.84-2.11, P = 0.23) in multivariable analysis. These results were consistent when considering alternate percentile cutpoints and alternate quantifications of biomarker staining.

CONCLUSIONS

Our results provide evidence that MDM2, p16, and p53 staining levels are not useful in the prediction of BCR after SRT. As such, these biomarkers are of little clinical use in the selection of appropriate candidates for SRT.

Permanent seed brachytherapy for locally recurrent prostate cancer after radical prostatectomy: a case report and review of the literature

PURPOSE

To describe the management of a patient with locally recurrent prostate cancer in the prostate bed, 10 years after a radical prostatectomy.

METHODS AND MATERIALS

A 71-year-old man had a radical prostatectomy for a Gleason 7 clinical T2a carcinoma of the prostate in 2000. Final pathologic stage was pT3a pN0. Postoperatively his prostate-specific antigen was undetectable, but by 2008 it was 1.0ng/mL and in 2011 it reached to 1.43ng/mL. He was referred for consideration of salvage radiotherapy. Staging workup was negative but transrectal ultrasound revealed a 15cc recurrence in the prostate bed. A combination of external beam radiation therapy (4600/23/4.5 weeks to the pelvis) and a brachytherapy boost (115Gy) was selected for definitive management. Androgen ablation was not used.

RESULTS

The treatment was well tolerated. The brachytherapy boost was planned in a similar fashion to a de novo implant for an intact prostate. The postimplant dosimetry was evaluated using magnetic resonance imaging-computed tomography (MR-CT) fusion and appeared satisfactory. Acute toxicity was minimal. Six months after brachytherapy, the prostate-specific antigen had fallen from 1.43 to 0.05ng/mL.

CONCLUSIONS

Dose escalation with combined external beam and brachytherapy may be feasible if recurrent disease can be visualized using transrectal ultrasound and encompassed in an implanted volume. Although longer followup and a larger series of patients are required to demonstrate safety and efficacy, consideration should be given this approach.