Nadir PSA is a strong predictor of treatment outcome in intermediate and high risk localized prostate cancer patients treated by definitive external beam radiotherapy and androgen deprivation

Significant Effect of Carbon-Ion Radiation Therapy Combined With Androgen Deprivation on Biochemical Recurrence Rates in High-Risk Prostate Cancer Patients: A Two-Center Controlled Trial Compare With X-Ray External Beam Radiation Therapy

OBJECTIVE

To compare the effects of carbon-ion radiation therapy (CIRT) and external beam radiotherapy (EBRT) on the prognosis of patients with prostate cancer.

METHODS

The effects of initial prostate-specific antigen (iPSA), clinical Tumor (cT) stage, radiotherapy method, and other clinical factors on the prognosis of 577 patients with radiotherapy were analyzed.

RESULTS

Cox regression analysis showed that CIRT (RR: 0.49, p = 0.0215), cT stage ≥ 3 (RR: 2.72, p = 0.0003), and iPSA ≥ 16 ng/mL (RR: 1.74, p = 0.0347) were independent predictors of biochemical recurrence (BCR). After propensity score matching (PSM), CIRT (RR: 0.42, p = 0.0147), cT stage ≥ 3 (RR: 2.55, p = 0.0092), and iPSA ≥ 16 ng/mL (RR: 2.12, p = 0.0366) were still the predictors of univariate analysis. In multivariate analysis, CIRT (RR: 0.42, p = 0.015) and cT stage≥ 3 (RR:2.21, p = 0.0332) were independent predictors of BCR. Among them, we used iPSA and cT stages to establish a new radiotherapy selection model based on BCR risk. Patients who met more than one factor (score ≥ 1) and underwent CIRT had significantly better BCR progression-free survival (PFS) than those who received EBRT (p ≤ 0.01). This was also confirmed by Kaplan-Meier analysis after PSM.

CONCLUSION

CIRT patients exhibited lower 5-year BCR rates compared to the EBRT group. Patients with a risk score of our model ≥ 1 undergoing CIRT were more likely to experience BCR benefits compared to those receiving EBRT.

Real-world outcomes in patients with metastatic castration-resistant prostate cancer beyond progression after upfront androgen receptor signaling inhibitor

BACKGROUND

Upfront androgen receptor signaling inhibitor (ARSI) along with androgen deprivation therapy is the current standard of care for metastatic castration-sensitive prostate cancer. However, evidence on second-line therapy after upfront ARSI is scarce. We aimed to evaluate the oncological outcome of ARSI versus docetaxel (DOC) after upfront ARSI therapy in a real-world clinical practice.

METHODS

Subjects were metastatic castration-resistant prostate cancer (mCRPC) patients who had progressed within 2 years of upfront ARSI therapy and received ARSI (ARSI group) or DOC (DOC group) as a second-line therapy. Second-line progression-free survival (second-line PFS), and second-line overall survival (second-line OS) were assessed. Propensity score matching (PSM) was used to adjust the clinicopathological features and treatment patterns.

RESULTS

A total of 101 mCRPC patients, 68 in the ARSI group, and 33 in the DOC group, were included in this analysis. Median second-line PFS was 6.3 months in the ARSI group and 4.9 months in the DOC group (p = 0.21). Median second-line OS was 25.0 months in the ARSI group and 14.2 months in the DOC group (p = 0.06). Prostate-specific antigen nadir ≤ 0.2 ng/ml during upfront ARSI therapy was significantly associated with improved second-line PFS. After PSM, no significant difference in second-line PFS and second-line OS were observed between the two groups.

CONCLUSION

ARSI or DOC has comparable oncologic outcomes in terms of second-line PFS and second-line OS. Further prospective research with longer follow-ups will be needed to identify the optimal treatment after upfront ARSI therapy.

Outcomes of I-125 Low-Dose-Rate Brachytherapy in Patients with Localized Prostate Cancer: A Comprehensive Analysis from a Specialized Tertiary Referral Center

Low-dose-rate (LDR) brachytherapy with I-125 seeds is one of the most common primary tumor treatments for low-risk and low-intermediate-risk prostate cancer. This report aimed to present an analysis of single-institution long-term results. We analyzed the treatment outcomes of 119 patients with low- and intermediate-risk prostate cancer treated with LDR brachytherapy at our institution between 2014 and 2020. The analysis focused on biochemical recurrence rates (BRFS), overall survival (OS), cumulative local recurrence rate (CLRR), and the incidence of acute and late toxicities. Patient-reported quality of life measures were also evaluated to provide a holistic view on the treatment's impact. The median follow-up period was 46 months. CLRR was 3.3% (4/119), five-year BRFS was 87%, and the five-year OS rate was 95%. Dysuria was the most common acute urinary toxicity, reported in 26.0% of patients as grade 1 and 13.4% as grade 2. As a late side effect, 12.6% of patients experienced mild dysuria. Sexual dysfunction persisted in 6.7% of patients as grade 1, 7.5% as grade 2, and 10.0% as grade 3. LDR brachytherapy in patients with prostate cancer is an effective treatment, with favorable clinical outcomes and manageable toxicity. The low CLRR and high OS rates, as well as low incidence of severe side effects, support the continued use of LDR brachytherapy as a primary treatment modality for localized prostate cancer.

Multiparametric MRI as a Predictor of PSA Response in Patients Undergoing Stereotactic Body Radiation Therapy for Prostate Cancer

Purpose

To maximize the therapeutic ratio, it is important to identify adverse prognostic features in men with prostate cancer, especially among those with intermediate risk disease, which represents a heterogeneous group. These men may benefit from treatment intensification. Prior studies have shown pretreatment mpMRI may predict biochemical failure in patients with intermediate and/or high-risk prostate cancer undergoing conventionally fractionated external beam radiation therapy and/or brachytherapy. This study aims to evaluate pretreatment mpMRI findings as a marker for outcome in patients undergoing stereotactic body radiation therapy (SBRT).

Methods and Materials

We identified all patients treated at our institution with linear accelerator based SBRT to 3625 cGy in 5 fractions, with or without androgen deprivation therapy (ADT) from November 2015 to March 2021. All patients underwent pretreatment Magnetic Resonance Imaging (MRI). Posttreatment Prostate Specific Imaging (PSA) measurements were typically obtained 4 months after SBRT, followed by every 3 to 6 months thereafter. A 2 sample t test was used to compare preoperative mpMRI features with clinical outcomes.

Results

One hundred twenty-three men were included in the study. Pretreatment MRI variables including median diameter of the largest intraprostatic lesion, median number of prostate lesions, and median maximal PI-RADS score, were each predictive of PSA nadir and time to PSA nadir (P < .0001). When separated by ADT treatment, this association remained for patients who were not treated with ADT (P < .001). In patients who received ADT, the pretreatment MRI variables were each significantly associated with time to PSA nadir (P < .01) but not with PSA nadir (P > 0.30). With a median follow-up time of 15.9 months (IQR: 8.5-23.3), only 3 patients (2.4%) experienced biochemical recurrence as defined by the Phoenix criteria.

Conclusions

Our experience shows the significant ability of mpMRI for predicting PSA outcome in prostate cancer patients treated with SBRT with or without ADT. Since PSA nadir has been shown to correlate with biochemical failure, this information may help radiation oncologists better counsel their patients regarding outcome after SBRT and can help inform future studies regarding who may benefit from treatment intensification with, for example, ADT and/or boosts to dominant intraprostatic lesions.

Evaluation of Recurrent Disease after Radiation Therapy for Patients Considering Local Salvage Therapy: Past vs. Contemporary Management

Recurrent prostate cancer after primary treatment with radiation therapy is a common problem. Patients with localized recurrence may benefit from salvage therapy, but careful patient selection is crucial because not all patients will benefit from local salvage therapy, and salvage therapy has increased morbidity compared to primary treatments for prostate cancer. This review aims to provide an overview of the evaluation of patients with recurrent disease after radiation therapy and how it is continuing to evolve with increasing data on outcomes, as well as improving technologies and techniques. Our enhanced understanding of treatment outcomes and risk stratification has influenced the identification of patients who may benefit from local salvage treatment. Advances in imaging and biopsy techniques have enhanced the accuracy of locating the recurrence, which affects treatment decisions. Additionally, the growing interest in image-targeted ablative therapies that have less morbidity and complications than whole-gland therapies for suitable patients influences the evaluation process for those considering focal salvage therapy. Although significant changes have been made in the diagnostic evaluation of patients with recurrent disease after radiation therapy, it remains unclear whether these changes will ultimately improve patient outcomes.

Early biochemical outcomes following neoadjuvant/adjuvant relugolix with stereotactic body radiation therapy for intermediate to high risk prostate cancer

Introduction

Injectable GnRH receptor agonists have been shown to improve cancer control when combined with radiotherapy. Prostate SBRT offers an abbreviated treatment course with comparable efficacy to conventionally fractionated radiotherapy. Relugolix is a new oral GnRH receptor antagonist which achieves rapid, sustained testosterone suppression. This prospective study sought to evaluate early testosterone suppression and PSA response following relugolix and SBRT for intermediate to high prostate cancer.

Methods

Relugolix was initiated at least 2 months prior to SBRT. Interventions to improve adherence were not utilized. PSA and total testosterone levels were obtained prior to and 1-4 months post SBRT. Profound castration was defined as serum testosterone ≤ 20 ng/dL. Early PSA nadir was defined as the lowest PSA value within 4 months of completion of SBRT. Per prior trials, we examined the percentage of patients who achieved PSA level of ≤ 0.5 ng/mL and ≤ 0.2 ng/mL during the first 4 months post SBRT.

Results

Between July 2021 and January 2023, 52 men were treated at Georgetown with relugolix (4-6 months) and SBRT (36.25-40 Gy in 5 fractions) per an institutional protocol (IRB 12-1775). Median age was 71 years. 26.9% of patients were African American and 28.8% were obese (BMI ≥30 kg/m2). The median pretreatment PSA was 9.1 ng/ml. 67% of patients were ≥ Grade Group 3. 44 patients were intermediate- and 8 were high-risk. Patients initiated relugolix at a median of 3.6 months prior to SBRT with a median duration of 6.2 total months. 92.3% of patients achieved profound castration during relugolix treatment. Poor drug adherence was observed in 2 patients. A third patient chose to discontinue relugolix due to side effects. By post-SBRT month 4, 87.2% and 74.4% of patients achieved PSA levels ≤ 0.5 ng/ml and ≤ 0.2 ng/ml, respectively.

Discussion

Relugolix combined with SBRT allows for high rates of profound castration with low early PSA nadirs. We observed a 96% testosterone suppresion rate without the utilization of scheduled cues/reminders. This finding supports the notion that patients with localized prostate cancer can consistently and successfully follow an oral ADT protocol without daily reminders. Given relugolix's potential benefits over injectable GnRH receptor agonists, its usage may be preferred in specific patient populations (fear of needles, prior cardiovascular events). Future studies should focus on boundaries to adherence in specific underserved populations.

Real-world comparison of Docetaxel versus new hormonal agents in combination with androgen-deprivation therapy in metastatic hormone-sensitive prostate cancer descrying PSA Nadir ≤ 0.05 ng/ml as marker for treatment response

PROPOSE

Using Docetaxel chemotherapy or new hormonal agents (NHT) to intensify upfront systemic therapy resulted in improved survival rates compared to androgen deprivation monotherapy (ADT). Hence, combination therapies have become the new standard of care (SOC) in metastatic hormone-sensitive prostate cancer (mHSPC). However, head-to-head trails comparing different therapies as well as treatment-guiding biomarkers are still lacking. Thus, the aim of the present study was to compare clinical outcomes of Docetaxel versus NHT therapy in the real-world setting as well as to elaborate biomarkers predicting clinical outcome.

METHODS

We retrospectively assessed overall-survival (OS), progression-free survival 1 and 2 (PFS1/2) and time to progression (TTP) in 42 patients treated by either ADT + NHT or ADT + Docetaxel. In addition, we investigated clinical prognostic biomarkers.

RESULTS

Our survival analysis revealed 3-year OS of 89.4% in the NHT group compared to 82.4% in the Docetaxel group. 3-year PFS1 was 59.6% in the NHT group compared to 32.2% in the Docetaxel group and the TTP was 53.8% vs 32.2% (pOS = 0.189; pPFS1 = 0.082; pTTP = 0.055). In addition, castration-resistance occurred more often in the Docetaxel group (78.6% vs 25%, p = 0.004). Interestingly, a PSA-Nadir ≤ 0.05 ng/ml during therapy was associated with increased survival rates (p < 0.001) while PSA levels at primary diagnosis had no influence on therapy outcome. Furthermore, a thyroid-stimulating hormone (TSH) increase during therapy was associated with improved clinical outcome (p = 0.06).

CONCLUSION

We observed a trend towards a higher benefit of NHT as first-line treatment compared to Docetaxel in men with mHSPC. Of note, a PSA-Nadir ≤ 0.05 ng/ml or a TSH-increase during therapy were predictors for therapy response.

A Personalized Clinical Dynamic Prediction Model to Characterize Prognosis for Patients With Localized Prostate Cancer: Analysis of the CHHiP Phase 3 Trial

PURPOSE

The CHHiP trial assessed moderately hypofractionated radiation therapy in localized prostate cancer. We utilized longitudinal prostate-specific antigen (PSA) measurements collected over time to evaluate and characterize patient prognosis.

METHODS AND MATERIALS

We developed a clinical dynamic prediction joint model to predict the risk of biochemical or clinical recurrence. Modeling included repeated PSA values and adjusted for baseline prognostic risk factors of age, tumor characteristics, and treatment received. We included 3071 trial participants for model development using a mixed-effect submodel for the longitudinal PSAs and a time-to-event hazard submodel for predicting recurrence of prostate cancer. We evaluated how baseline prognostic factor subgroups affected the nonlinear PSA levels over time and quantified the association of PSA on time to recurrence. We assessed bootstrapped optimism-adjusted predictive performance on calibration and discrimination. Additionally, we performed comparative dynamic predictions on patients with contrasting prognostic factors and investigated PSA thresholds over landmark times to correlate with prognosis.

RESULTS

Patients who developed recurrence had generally higher baseline and overall PSA values during follow-up and had an exponentially rising PSA in the 2 years before recurrence. Additionally, most baseline risk factors were significant in the mixed-effect and relative-risk submodels. PSA value and rate of change were predictive of recurrence. Predictive performance of the model was good across different prediction times over an 8-year period, with an overall mean area under the curve of 0.70, mean Brier score of 0.10, and mean integrated calibration index of 0.048; these were further improved for predictions after 5 years of accrued longitudinal posttreatment PSA assessments. PSA thresholds <0.23 ng/mL after 3 years were indicative of a minimal risk of recurrence by 8 years.

CONCLUSIONS

We successfully developed a joint statistical model to predict prostate cancer recurrence, evaluating prognostic factors and longitudinal PSA. We showed dynamically updated PSA information can improve prognostication, which can be used to guide follow-up and treatment management options.

Outcome of the first 200 patients with prostate cancer treated with MRI-Linac at Assuta MC

Background

We present our experience with MR-guided stereotactic body radiotherapy (SBRT) for 200 consecutive patients with prostate cancer with minimum 3-month follow-up.

Methods

Treatment planning included fusion of the 0.35-Tesla planning MRI with multiparametric MRI and PET-PSMA for Group Grade (GG) 2 or higher and contour review with an expert MRI radiologist. No fiducials or rectal spacers were used. Prescription dose was 36.25 Gy in 5 fractions over 2 weeks to the entire prostate with 3-mm margins. Daily plan was adapted if tumor and organs at risk (OAR) doses differed significantly from the original plan. The prostate was monitored during treatment that was automatically interrupted if the target moved out of the PTV range.

Results

Mean age was 72 years. Clinical stage was T1c, 85.5%; T2, 13%; and T3, 1.5%. In addition, 20% were GG1, 50% were GG2, 14.5% were GG3, 13% were GG4, and one patient was GG5. PSA ranged from 1 to 77 (median, 6.2). Median prostate volume was 57cc, and 888/1000 (88%) fractions required plan adaptation. The most common acute GU toxicity was Grade I, 31%; dysuria and acute gastrointestinal toxicity were rare. Three patients required temporary catheterization. Prostate size of over 100cc was associated with acute fatigue, urinary hesitance, and catheter insertion. Prostate Specific Antigen (PSA) decreased in 99% of patients, and one patient had regional recurrence.

Conclusion

MR-guided prostate SBRT shows low acute toxicity and excellent short-term outcomes. Real-time MRI ensures accurate positioning and SBRT delivery.

Adjusting the duration of androgen deprivation therapy (ADT) based on nadir PSA for high risk localized prostate cancer patients treated with definitive external beam radiation therapy and ADT

BACKGROUND

A nadir Prostate-Specific Antigen (nPSA) of 0.06 ng/mL has been shown to be a strong independent predictor of biochemical recurrence-free survival (bRFS) in patients with intermediate or high-risk (HR) prostate cancer treated with definitive external beam radiation therapy (RT) and androgen deprivation therapy (ADT). We aimed to examine the association between the duration of ADT and bRFS in HR localized prostate cancer, based on nPSA.

METHODS

Between 1998 and 2015, 204 patients with HR localized prostate cancer were identified. Of them, 157 patients (77.0%) reached the desired nPSA of < 0.06 ng/mL (favorable group), while 47 (23.0%) did not (unfavorable group). Duration of ADT varied among patients depending on physician preference, patient tolerance, and/or compliance. Survival outcomes were calculated using Kaplan-Meier methods and predictors of outcomes using multi-variable cox regression model.

RESULTS

In the favorable group, ADT for at least 12 months lead to superior bRFS compared to ≤ 9 months of ADT (P = 0.036). However, no significant difference was seen when examining the value of receiving ADT beyond 12, 18, or 24 months, respectively. On univariate analysis for bRFS, the use of ADT for at least 12 months was significant (P = 0.012) as well as time to nadir PSA (tnPSA), (≤ 6 vs > 6 months); (P = 0.043). The presenting T stage was borderline significant (HR 3.074; 95% CI 0.972-9.719; P = 0.056), while PSA at presentation, Gleason Score and age were not. On multivariate analysis, the use of ADT for 12 months (P = 0.012) and tnPSA (P = 0.037) remained significant. In the unfavorable group, receiving ADT beyond 9 and 12 months was associated with improved bRFS (P = 0.044 and 0.019, respectively). However, beyond 18 months, there was no significant difference.

CONCLUSION

In HR localized prostate cancer patients treated with definitive RT and ADT, the total duration of ADT may be adjusted according to treatment response using nPSA. In patients reaching a nPSA below 0.06 ng/mL, a total of 12 months of ADT may be sufficient, while in those not reaching a nPSA below 0.06 ng/mL, a total duration of 18 months is required.

Prostate-specific antigen nadir within 1 year of radiotherapy combined with hormone therapy predicts cancer-specific mortality and biochemical recurrence-free survival in prostate cancer patients

Background

In this study, we investigated the ability of prostate-specific antigen (PSA) 12 months after (nPSA12) external beam radiotherapy (EBRT) combined with androgen deprivation therapy (ADT) to predict biochemical recurrence-free survival (BRFS), overall survival (OS), and prostate cancer-specific mortality (PCSM) in intermediate- and high-risk prostate cancer patients.

Methods

We retrospectively reviewed the clinical data of 338 intermediate- and high-risk prostate cancer patients treated with EBRT with ADT at our institution between 2000 and 2018. The median radiation dose was 76 Gy, the median initial PSA level was 17 ng/mL (range, 1–228 ng/mL), and the median duration of ADT was 24 months (range, 6–167 months). The median PSA level 1 months after EBRT was 0.06 ng/mL (range, 0–25.6 ng/mL). Univariate and multivariate analyses were performed. Patient survival was assessed using the Kaplan-Meier method and Cox proportional hazards regression analyses.

Results

The median follow-up time was 5 years (range, 1–20 years). Multivariate analysis revealed that nPSA was an independent and significant factor associated with OS, PCSM, and BRFS (P = 0.008, P = 0.001, P = 0.04). Furthermore, the time to nPSA12 was an independent predictor of PCSM and BRFS (P = 0.042, P = 0.021). Pelvic irradiation was also significantly associated with worse OS and PCSM (P = 0.004, P = 0.01). Additionally, age (≤ 70 or > 70 years) and hormone therapy duration (6 months, 1–3 years, or > 3 years) were significantly associated with OS and PCSM, respectively (P = 0.004, P = 0.02). For high risk, nPSA and nPSA12 were an independent predictor for BRFS. (P = 0.021, P = 0.029)

Conclusion

The nPSA12 level of > 0.06 ng/mL may independently predict worse PCSM and BRFS in intermediate- and high-risk prostate cancer patients undergoing EBRT and ADT. Additionally, for high risk, nPSA > 0.06 ng/mL and nPSA12 > 0.06 ng/mL may independently predict worse BRFS.

Race-specific prostate cancer outcomes in a cohort of low and favorable-intermediate risk patients who underwent external beam radiation therapy from 1990 to 2017

BACKGROUND

Previous research exploring the role of race on prostate cancer (PCa) outcomes has demonstrated greater rates of disease progression and poorer overall survival for African American (AA) compared to Caucasian American (CA) men. The current study examines self-reported race as a predictor of long-term PCa outcomes in patients with low and favorable-intermediate risk disease treated with external beam radiation therapy (EBRT).

METHODS

This retrospective cohort study examined patients who were consented to enrollment in the Center for Prostate Disease Research Multicenter National Database between January 01, 1990 and December 31, 2017. Men self-reporting as AA or CA who underwent EBRT for newly diagnosed National Comprehensive Cancer Network-defined low or favorable-intermediate risk PCa were included. Dependent study outcomes included: biochemical recurrence-free survival, (ii) distant metastasis-free survival, and (iii) overall survival. Each outcome was modeled as a time-to-event endpoint using race-stratified Kaplan-Meier estimation curves and multivariable Cox proportional hazards analysis.

RESULTS

Of 840 men included in this study, 268 (32%) were AA and 572 (68%) were CA. The frequency of biochemical recurrence, distant metastasis, and deaths from any cause was 151 (18.7%), 29 (3.5%), and 333 (39.6%), respectively. AA men had a significantly younger median age at time of EBRT and slightly higher biopsy Gleason scores. Multivariable Cox proportional hazards analyses demonstrated no racial differences in any of the study endpoints.

CONCLUSIONS

These findings reveal no racial disparity in PCa outcomes for AA compared to CA men, in a long-standing, longitudinal cohort of patients with comparable access to cancer care.

Comparison of Different Machine Learning Models in Prediction of Postirradiation Recurrence in Prostate Carcinoma Patients

After primary treatment of localized prostate carcinoma (PC), up to a third of patients have disease recurrence. Different predictive models have already been used either for initial stratification of PC patients or to predict disease recurrence. Recently, artificial intelligence has been introduced in the diagnosis and management of PC with a potential to revolutionize this field. The aim of this study was to analyze machine learning (ML) classifiers in order to predict disease progression in the moment of prostate-specific antigen (PSA) elevation during follow-up. The study cohort consisted of 109 PC patients treated with external beam radiotherapy alone or in combination with androgen deprivation therapy. We developed and evaluated the performance of two ML algorithms based on artificial neural networks (ANN) and naïve Bayes (NB). Of all patients, 72.5% was randomly selected for a training set while the remaining patients were used for testing of the models. The presence/absence of disease progression was defined as the output variable. The input variables for models were conducted from the univariate analysis preformed among two groups of patients in the training set. They included two pretreatment variables (UICC stage and Gleason's score risk group) and five posttreatment variables (nadir PSA, time to nadir PSA, PSA doubling time, PSA velocity, and PSA in the moment of disease reevaluation). The area under the receiver operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value, and predictive accuracy was calculated to test the models' performance. The results showed that specificity was similar for both models, while NB achieved better sensitivity then ANN (100.0% versus 94.4%). The ANN showed an accuracy of 93.3%, and the matching for NB model was 96.7%. In this study, ML classifiers have shown potential for application in routine clinical practice during follow-up when disease progression was suspected.

Defining Biochemical Cure After Low Dose Rate Prostate Brachytherapy: External Validation of 4-year Prostate-specific Antigen Nadir as a Predictor of 10- and 15-year Disease-free Survival

AIMS

To externally validate a proposed biochemical definition of cure following low dose rate (LDR) brachytherapy for prostate cancer - 4-year post-implant prostate-specific antigen (PSA) ≤0.2 ng/ml - in a UK population, and report the long-term (10- and 15-year) outcomes for patients stratified by National Comprehensive Cancer Network (NCCN) risk groups, through analysis of a large, prospectively collected, single-centre database.

MATERIALS AND METHODS

All patients treated with LDR brachytherapy for prostate cancer at a single UK centre between 2001 and November 2020 (n = 1142) were eligible; 632 patients met the inclusion criteria for the analysis. The primary end point was disease-free survival (DFS), defined as freedom from clinical, radiological or PSA progression requiring androgen deprivation therapy. Four-year PSA was categorised as ≤0.2, >0.2 to ≤0.5, >0.5 to ≤1.0 and >1.0 ng/ml. Kaplan-Meier analysis to 15 years was undertaken for each group, and sensitivity and specificity of 4-year PSA as a surrogate for long-term cure were calculated. Kaplan-Meier analysis to 15 years was repeated, stratifying patients by NCCN risk groups.

RESULTS

The median cohort age was 63 years; the median follow-up was 9.1 years (range 3.5-18.7). In total, 248 patients were available for analysis at year 10, 46 at year 15. Sixty-four patients (10.1%) relapsed during the study period. The 10-year DFS for 4-year PSA categories ≤0.2, >0.2 to ≤0.5, >0.5 to ≤1.0 and >1.0 ng/ml (95% confidence intervals) were 97.5% (95.4-99.6), 89.0% (82.4-96.1), 81.5% (70.5-94.2) and 41.8% (29.7-58.9), respectively. The 10-year DFS results for NCCN low, favourable-intermediate and unfavourable-intermediate risk disease were 93.1% (89.6-96.7), 92.1% (87.6-96.9) and 75.9% (67.8-84.9), respectively.

CONCLUSIONS

Patients with 4-year PSA ≤0.2 ng/ml may be considered cured, and could be discharged to general practitioner follow-up. LDR brachytherapy is an excellent treatment option for patients with low and favourable-intermediate risk prostate cancer, but those with unfavourable-intermediate risk disease should be considered for treatment intensification strategies.

Clinical predictors for biochemical failure in patients with positive surgical margin after robotic-assisted radical prostatectomy

OBJECTIVE

Patients with positive surgical margins (PSMs) after radical prostatectomy for localized prostate cancer have a higher risk of biochemical failure (BCF). We investigated the risk factors of BCF in patients with PSMs after robotic-assisted radical prostatectomy (RARP).

METHODS

We evaluated 462 patients who underwent RARP in a single medical center from 2006 through 2013. Of them, 61 with PSMs did not receive any treatment before BCF. Kaplan-Meier curve and Cox regression analysis were used to compare patients with (n = 19) and without (n = 41) BCF.

RESULTS

Overall, 13.2% of patients had PSMs, and of those, 31.7% experienced BCF during follow-up. The mean follow-up duration was 43.7 months (42.4 [non-BCF] vs 46.35 (BCF], p = 0.51). In univariant analyses, the platelet to lymphocyte ratio (6.26 [non-BCF] vs 8.02 [BCF], p = 0.04) differed statistically. When patients were grouped by pathologic grade ≦2 or ≧3 (p = 0.004), the BCF-free survival rates differed significantly. Seminal vesicle invasion also differed significantly (5 [non-BCF] vs 7 [BCF], p = 0.005). Patients with undetectable nadir prostate-specific antigen (PSA) after RARP (BCF rate 4/34) differed statistically from those with detectable PSA after RARP (BCF rate 15/26) (p < 0.001). In the multivariate analysis, the platelet/lymphocyte (P/L) ratio, pathologic grade, and undetectable nadir PSA remained statistically significant.

CONCLUSIONS

In patients who undergo RARP and have PSMs, P/L ratio >9 preoperatively, pathologic grade ⩾3, and detectable nadir PSA after RARP should be considered adverse features. Early intervention such as salvage radiation therapy or androgen deprivation therapy should be offered to these patients.

Favorable prognosis of patients who received adjuvant androgen deprivation therapy after radiotherapy achieving undetectable levels of prostate-specific antigen in high- or very high-risk prostate cancer

INTRODUCTION

To determine the prognostic significance of long-term adjuvant androgen deprivation therapy (A-ADT) over 1 year in achieving undetectable levels of prostate-specific antigen (PSA) less than 0.001 ng/mL in prostate cancer patients with high- or very high-risk prostate cancer who underwent radiotherapy (RT).

MATERIALS AND METHODS

A total of 197 patients with prostate cancer received RT, with a follow-up of ≥12 months. Biochemical failure was defined as PSA ≥nadir + 2 ng/mL after RT. We analyzed clinical outcomes, including survival, failure patterns, and prognostic factors affecting outcomes.

RESULTS

Biochemical failure-free survival (BCFFS), clinical failure-free survival, distant metastasis-free survival, cancer-specific survival, and overall survival (OS) rates at 5 years were 91.1%, 95.4%, 96.9%, 99.5%, and 89.1%, respectively. Administration of long-term A-ADT significantly predicted favorable BCFFS (p = 0.027) and OS (p < 0.001) in multivariate analysis. Nadir PSA ≤0.001 ng/mL was an independent prognostic factor for BCFFS (p = 0.006) and OS (p = 0.021). The use of long-term A-ADT significantly affected nadir PSA ≤0.001 ng/mL (p < 0.001). The patients with A-ADT for 1 year or longer had better BCFFS or OS than those for less than 1 year or those without A-ADT (p < 0.001). The best prognosis was demonstrated in patients treated with long-term A-ADT and nadir PSA ≤0.001 ng/mL in BCFFS (p < 0.001).

CONCLUSION

The addition of long-term A-ADT over 1 year to RT demonstrated good treatment outcomes in patients with locally advanced prostate cancer. Achieving a nadir PSA value ≤0.001 ng/mL using combination therapy with RT and A-ADT is a powerful clinical predictor of treatment outcomes.

Magnetic resonance image-guided adaptive stereotactic body radiotherapy for prostate cancer: preliminary results of outcome and toxicity

OBJECTIVE

Using moderate or ultra-hypofractionation, which is also known as stereotactic body radiotherapy (SBRT) for treatment of localized prostate cancer patients has been increased. We present our preliminary results on the clinical utilization of MRI-guided adaptive radiotherapy (MRgRT) for prostate cancer patients with the workflow, dosimetric parameters, toxicities and prostate-specific antigen (PSA) response.

METHODS

50 prostate cancer patients treated with ultra-hypofractionation were included in the study. Treatment was performed with intensity-modulated radiation therapy (step and shoot) technique and daily plan adaptation using MRgRT. The SBRT consisted of 36.25 Gy in 5 fractions with a 7.25 Gy fraction size. The time for workflow steps was documented. Patients were followed for the acute and late toxicities and PSA response.

RESULTS

The median follow-up for our cohort was 10 months (range between 3 and 29 months). The median age was 73.5 years (range between 50 and 84 years). MRgRT was well tolerated by all patients. Acute genitourinary (GU) toxicity rate of Grade 1 and Grade 2 was 28 and 36%, respectively. Only 6% of patients had acute Grade 1 gastrointestinal (GI) toxicity and there was no Grade ≥ 2 GI toxicity. To date, late Grade 1 GU toxicity was experienced by 24% of patients, 2% of patients experienced Grade 2 GU toxicity and 6% of patients reported Grade 2 GI toxicity. Due to the short follow-up, PSA nadir has not been reached yet in our cohort.

CONCLUSION

In conclusion, MRgRT represents a new method for delivering SBRT with markerless soft tissue visualization, online adaptive planning and real-time tracking. Our study suggests that ultra-hypofractionation has an acceptable acute and very low late toxicity profile.

ADVANCES IN KNOWLEDGE

MRgRT represents a new markerless method for delivering SBRT for localized prostate cancer providing online adaptive planning and real-time tracking and acute and late toxicity profile is acceptable.

Successful Development of a Competency-Based Residency Training Program in Radiation Oncology: Our 15-Year Experience from Within a Developing Country

One of the main challenges of delivering high quality of care to cancer patients in developing countries is the lack of well-trained radiation oncologists. This is a direct cause for the lack of residency programs coupled with lack of resources. This article describes and details establishments of a successful and sustainable radiation-oncology residency program in our country. The program has been in operation for 14 years and has trained and graduated radiation oncologists who are now working in various countries. The curriculum of the 4-year residency program, fashioned according to American College of Radiologists (ACR) recommendations, includes site-specific clinical rotations and didactic lectures in clinical oncology, radiobiology, medical physics, statistics, and epidemiology. It also includes a component of advanced clinical experience in the form of 3-month externship at one of collaborating centers outside the country. Evaluation of the residents is conducted annually via written exams and 360° feedback. Residents also sit for the formal certification exam in radiation oncology from the national Medical Council. The exam consists of 2 written exams and one oral. As a form of benchmarking residents' knowledge, they are required to sit for the ACR examinations held annually and conducted in Amman in tandem. The program has successfully trained and graduated 28 residents, who now work as consultant radiation oncologists locally and abroad. Each resident has gone through a structured training that includes exposure to a Western-style patient-management culture, enhancing the breadth and width of their clinical experience. The residency program, initiated in a developing country, underwent many challenges, yet it overcome all obstacles and resulted in a successful training of competent radiation oncologists serving the region.

Proof-of-principle Phase I results of combining nivolumab with brachytherapy and external beam radiation therapy for Grade Group 5 prostate cancer: safety, feasibility, and exploratory analysis

BACKGROUND

To determine whether combining brachytherapy with immunotherapy is safe in prostate cancer (PCa) and provides synergistic effects, we performed a Phase I/II trial on the feasibility, safety, and benefit of concurrent delivery of anti-PD-1 (nivolumab) with high-dose-rate (HDR) brachytherapy and androgen deprivation therapy (ADT) in patients with Grade Group 5 (GG5) PCa.

METHODS

Eligible patients were aged 18 years or older with diagnosis of GG5 PCa. Patients received ADT, nivolumab every two weeks for four cycles, with two cycles prior to first HDR, and two more cycles prior to second HDR, followed by external beam radiotherapy. The primary endpoint was to determine safety and feasibility. This Phase I/II trial is registered with ClinicalTrials.gov (NCT03543189).

RESULTS

Between September 2018 and June 2019, six patients were enrolled for the Phase I safety lead-in with a minimum observation period of 3 months after nivolumab administration. Overall, nivolumab was well tolerated in combination with ADT and HDR treatment. One patient experienced a grade 3 dose-limiting toxicity (elevated Alanine aminotransferase and Aspartate aminotransferase) after the second cycle of nivolumab. Three patients (50%) demonstrated early response with no residual tumor detected in ≥4 of 6 cores on biopsy post-nivolumab (4 cycles) and 1-month post-HDR. Increase in CD8+ and FOXP3+/CD4+ T cells in tissues, and CD4+ effector T cells in peripheral blood were observed in early responders.

CONCLUSION

Combination of nivolumab with ADT and HDR is well tolerated and associated with evidence of increased immune infiltration and antitumor activity.

Ten-Year Results From a Phase II Study on Image Guided, Intensity Modulated Radiation Therapy With Simultaneous Integrated Boost in High-Risk Prostate Cancer

Purpose

There is no consensus on how to treat high-risk prostate cancer, and long-term results from hypofractionated radiation therapy are lacking. We report 10-year results after image guided, intensity modulated radiation therapy with hypofractionated simultaneous integrated boost and elective pelvic field.

Methods and Materials

Between 2007 and 2009, 97 consecutive patients with high-risk prostate cancer were included, treated with 2.7 to 2.0 Gy × 25 Gy to the prostate, seminal vesicles, and elective pelvic field. Toxicity was scored according to Radiation Therapy Oncology Group criteria and biochemical disease-free survival (BFS) defined by the Phoenix definition. Patients were subsequently divided into 3 groups: high risk (HR; n = 32), very high risk (VHR; n = 50), and N+/s–prostate-specific antigen (PSA) ≥100 (n = 15). Differences in outcomes were examined using Kaplan-Meier analyses.

Results

BFS in the patients at HR and VHR was 64%, metastasis-free survival 80%, prostate cancer-specific survival 90%, and overall survival (OS) 72%. VHR versus HR subgroups demonstrated significantly different BFS, 54% versus 79% (P = .01). Metastasis-free survival and prostate cancer-specific survival in the VHR group versus HR group were 76% versus 87% (P = .108) and 74% versus 100% (P = .157). Patients reaching nadir PSA <0.1 (n = 80) had significantly better outcomes than the rest (n = 17), with BFS 70% versus 7% (P < .001). Acute grade 2 gastrointestinal tract (GI) and genitourinary tract (GU) toxicity occurred in 27% and 40%, grade 3 GI and GU toxicity in 1% and 3%. Late GI and GU grade 2 toxicity occurred in 1% and 8%.

Conclusions

High-risk prostate cancer patients obtained favorable 10-year outcomes with low toxicity. There were significantly better results in the HR versus the VHR group, both better than the N+/PSA ≥100 group. A nadir PSA value < 0.1 predicted good prognosis.

Management of patients with high-risk and advanced prostate cancer in the Middle East: resource-stratified consensus recommendations

Purpose

Prostate cancer care in the Middle East is highly variable and access to specialist multidisciplinary management is limited. Academic tertiary referral centers offer cutting-edge diagnosis and treatment; however, in many parts of the region, patients are managed by non-specialists with limited resources. Due to many factors including lack of awareness and lack of prostate-specific antigen (PSA) screening, a high percentage of men present with locally advanced and metastatic prostate cancer at diagnosis. The aim of these recommendations is to assist clinicians in managing patients with different levels of access to diagnostic and treatment modalities.

Methods

The first Advanced Prostate Cancer Consensus Conference (APCCC) satellite meeting for the Middle East was held in Beirut, Lebanon, November 2017. During this meeting a consortium of urologists, medical oncologists, radiation oncologist and imaging specialists practicing in Lebanon, Syria, Iraq, Kuwait and Saudi Arabia voted on a selection of consensus questions. An additional workshop to formulate resource-stratified consensus recommendations was held in March 2019.

Results

Variations in practice based on available resources have been proposed to form resource-stratified recommendations for imaging at diagnosis, initial management of localized prostate cancer requiring therapy, treatment of castration-sensitive/naïve advanced prostate cancer and treatment of castration-resistant prostate cancer.

Conclusion

This is the first regional consensus on prostate cancer management from the Middle East. The following recommendations will be useful to urologists and oncologists practicing in all areas with limited access to specialist multi-disciplinary teams, diagnostic modalities and treatment resources.

Electronic supplementary material

The online version of this article (10.1007/s00345-019-02872-x) contains supplementary material, which is available to authorized users.

Analysis of Circulating Tumor Cells in Patients with Non-Metastatic High-Risk Prostate Cancer before and after Radiotherapy Using Three Different Enumeration Assays

The characterization of circulating tumor cells (CTCs) can lead to a promising strategy for monitoring residual or relapsing prostate cancer (PCa) after local therapy. The aim of this study was to compare three innovative technologies for CTC enumeration in 131 high-risk patients with PCa, before and after radiotherapy, combined with androgen deprivation. The CTC number was tested using the FDA-cleared CellSearch^® system, the dual fluoro-EPISPOT assay that only detects functional CTCs, and the in vivo CellCollector^® technology. The highest percentage of CTC-positive patients was detected with the CellCollector^® (48%) and dual fluoro-EPISPOT (42%) assays, while the CellSearch^® system presented the lowest rate (14%). Although the concordance among methods was only 23%, the cumulative positivity rate was 79%. A matched-pair analysis of the samples before, and after, treatment suggested a trend toward a decrease in CTC count after treatment with all methods. CTC tended to be positivity correlated with age for the fluoro-EPISPOT assay and with PSA level from the data of three assays. Combining different CTC assays improved CTC detection rates in patients with non-metastatic high-risk PCa before and after treatment. Our findings do not support the hypothesis that radiotherapy leads to cancer cell release in the circulation.