Short-term neoadjuvant androgen deprivation and radiotherapy for locally advanced prostate cancer: 10-year data from the TROG 96.01 randomised trial

Neoadjuvant lutetium PSMA, the TIME and immune response in high-risk localized prostate cancer

High-risk localized prostate cancer remains a lethal disease with high rates of recurrence, metastases and death, despite attempts at curative local treatment including surgery. Disease recurrence is thought to be a result of failure of local control and occult micrometastases. Neoadjuvant strategies before surgery have been effective in many cancers, but, to date, none has worked in this setting for prostate cancer. Prostate-specific membrane antigen (PSMA)-based theranostics is an exciting and rapidly evolving field in prostate cancer. The novel intravenous radionuclide therapy, [177Lu]Lu-PSMA-617 (lutetium PSMA) has been shown to be effective in treating men with metastatic castration-resistant prostate cancer, targeting cells expressing PSMA throughout the body. When given in a neoadjuvant setting, lutetium PSMA might also improve long-term oncological outcomes in men with high-risk localized disease. A component of radiotherapy is potentially an immunogenic form of cancer cell death. Lutetium PSMA could cause cancer cell death, resulting in release of tumour antigens and induction of a tumour-specific systemic immune response. This targeted radioligand treatment has the potential to treat local and systemic tumour sites by directly targeting cells that express PSMA, but might also act indirectly via this systemic immune response. In selected patients, lutetium PSMA could potentially be combined with systemic immunotherapies to augment the antitumour T cell response, and this might produce long-lasting immunity in prostate cancer.

Impact of neoadjuvant androgen deprivation therapy on toxicity in intensity-modulated radiation therapy for prostate cancer

This study aimed to compare toxicities, prostate volume and dosimetry, between patients who underwent intensity-modulated radiation therapy (IMRT) combined with ≥3 months of neoadjuvant androgen deprivation therapy (NADT) and those without NADT for prostate cancer. In total, 449 patients with intermediate- and high-risk prostate cancer received 78 Gy IMRT in 39 fractions, of which 129 were treated without any ADT (non-ADT group) and 320 with NADT ≥3 months (NADT group). Adverse events and dose-volume indices were compared between the two groups retrospectively. The NADT group had a lower rate of acute grade 2 gastrointestinal (GI) toxicities (17% vs 25%, P = 0.063) and late grade 2 GI toxicities (P = 0.055), including a significantly lower rate of late grade 2 rectal hemorrhage (P = 0.033), compared with the non-ADT group. There were no cases of late grade 3 or higher GI toxicities. The average volume of the prostate in the NADT group was 38% smaller than that in the non-ADT group (43.7 vs 27.0 cm3, P < 0.001). Bladder V40Gy and V50Gy, and rectum V40Gy, V50Gy, V60Gy and V70Gy were significantly smaller in the NADT group. In the NADT group, no significant difference was observed in adverse events or dosimetry between the subgroups with NADT ≥12 and <12 months. Acute and late rectal toxicities were reduced by NADT within ≥3 months in accordance with reduced prostate volume and improved rectal dosimetry. This suggests a merit of administering neoadjuvant ADT ≥3 months for reducing rectal toxicities.

Testosterone Recovery Following Androgen Suppression and Prostate Radiotherapy (TRANSPORT): A Pooled Analysis of Five Randomized Trials from the Meta-Analysis of Randomized Trials in Cancer of the Prostate (MARCAP) Consortium

BACKGROUND AND OBJECTIVE

Time to testosterone recovery (TR) following androgen deprivation therapy (ADT) with gonadotropin-releasing hormone agonists varies widely. We evaluate TR kinetics and the oncological impact of an effective castration period in patients receiving definitive radiotherapy and ADT for prostate cancer.

METHODS

We obtained individual patient data from randomized controlled trials of radiotherapy with ADT and prospectively collected serial testosterone data from the MARCAP Consortium. We estimated the times to noncastrate TR (>1.7 nmol/l) and nonhypogonadal TR (>8.0 nmol/l) were estimated for each prescribed ADT duration, and developed corresponding nomograms. The association between effective castration period and metastasis-free survival (MFS) for any given ADT duration was evaluated via multivariable Cox regression. We conducted cubic spline analyses to assess nonlinear associations.

KEY FINDINGS AND LIMITATIONS

We included 1444 men from five trials in the analysis, of whom 115 received 4 mo, 880 received 6 mo, 353 received 18 mo, 36 received 28 mo, and 60 received 36 mo of ADT. Times to noncastrate TR and to nonhypogonadal TR varied considerably by ADT duration. Higher baseline testosterone and lower age were associated with a higher likelihood of TR (p < 0.001 for both). Effective castration period was not linearly associated with MFS for any ADT duration on Cox regression. Cubic spline analysis revealed that the optimal effective castration period for an MFS benefit was 10.6 mo for men who received 6 mo of ADT and 18 mo for men who received 18 mo of ADT.

CONCLUSIONS AND CLINICAL IMPLICATIONS

Time to TR varies according to the ADT duration, baseline testosterone, and age. The relationship between effective castration period and MFS may be nonlinear, with a longer effective castration period being helpful for men receiving 6 mo of ADT.

Delayed definitive management of localized prostate cancer: what do we know?

Delays in the work-up and definitive management of patients with prostate cancer are common, with logistics of additional work-up after initial prostate biopsy, specialist referrals, and psychological reasons being the most common causes of delays. During the COVID-19 pandemic and the subsequent surges, timing of definitive care delivery with surgery or radiotherapy has become a topic of significant concern for patients with prostate cancer and their providers alike. In response, recommendations for the timing of definitive management of prostate cancer with radiotherapy and radical prostatectomy were published but without a detailed rationale for these recommendations. While the COVID-19 pandemic is behind us, patients are always asking the question: "When should I start radiation or undergo surgery?" In the absence of level I evidence specifically addressing this question, we will hereby present a narrative review to summarize the available data on the effect of treatment delays on oncologic outcomes for patients with localized prostate cancer from prospective and retrospective studies.

The extracellular matrix component perlecan/HSPG2 regulates radioresistance in prostate cancer cells

Radiotherapy of prostate cancer (PC) can lead to the acquisition of radioresistance through molecular mechanisms that involve, in part, cell adhesion-mediated signaling. To define these mechanisms, we employed a DU145 PC model to conduct a comparative mass spectrometry-based proteomic analysis of the purified integrin nexus, i.e., the cell-matrix junction where integrins bridge assembled extracellular matrix (matrisome components) to adhesion signaling complexes (adhesome components). When parental and radioresistant cells were compared, the expression of integrins was not changed, but cell radioresistance was associated with extensive matrix remodeling and changes in the complement of adhesion signaling proteins. Out of 72 proteins differentially expressed in the parental and radioresistant cells, four proteins were selected for functional validation based on their correlation with biochemical recurrence-free survival. Perlecan/heparan sulfate proteoglycan 2 (HSPG2) and lysyl-like oxidase-like 2 (LOXL2) were upregulated, while sushi repeat-containing protein X-linked (SRPX) and laminin subunit beta 3 (LAMB3) were downregulated in radioresistant DU145 cells. Knockdown of perlecan/HSPG2 sensitized radioresistant DU145 RR cells to irradiation while the sensitivity of DU145 parental cells did not change, indicating a potential role for perlecan/HSPG2 and its associated proteins in suppressing tumor radioresistance. Validation in androgen-sensitive parental and radioresistant LNCaP cells further supported perlecan/HSPG2 as a regulator of cell radiosensitivity. These findings extend our understanding of the interplay between extracellular matrix remodeling and PC radioresistance and signpost perlecan/HSPG2 as a potential therapeutic target and biomarker for PC.

Elective Pelvic Lymph Node Radiation Therapy and the Risk of Death in Patients With Unfavorable-Risk Prostate Cancer: A Postrandomization Analysis

PURPOSE

Although a contemporary randomized clinical trial has led to the use of whole-pelvic radiation therapy (WPRT), long-term data evaluating a potential reduction in mortality are lacking and are addressed in the current study.

MATERIALS AND METHODS

From 2005 to 2015, 350 men with localized, unfavorable-risk prostate cancer (PC) were randomly assigned to receive androgen deprivation therapy (ADT) and RT plus docetaxel versus ADT and RT. Treatment of the pelvic lymph nodes was at the discretion of the treating physician. Multivariable Cox and Fine and Grays regression analyses were performed to assess whether a significant association existed between radiation treatment volume and all-cause mortality (ACM) and PC-specific mortality (PCSM), respectively, adjusting for known PC prognostic factors and comorbidity. An interaction term between age (categorized by dichotomization at 65 years to enable clinical interpretation and applicability of the results and which approximates the median (66 years [IQR, 61-70]) and radiation treatment volume was included in the analysis.

RESULTS

After a median follow-up of 10.20 years (IQR, 7.96-11.41), 89 men died (25.43%); of these, 42 died of PC (47.19%). Of the 350 randomly assigned patients, 88 (25.14%) received WPRT. In men younger than 65 years, WPRT was associated with a significantly lower ACM risk (adjusted hazard ratio [AHR], 0.33 [95% CI, 0.11 to 0.97]; P = .04) and lower PCSM risk (AHR, 0.17 [95% CI, 0.02 to 1.35]; P = .09) after adjusting for covariates, whereas this was not the case for men 65 years or older.

CONCLUSION

WPRT has the potential to reduce mortality in younger men with unfavorable-risk PC.

Population-based study of disease trajectory after radical treatment for high-risk prostate cancer

OBJECTIVES

To investigate long-term disease trajectories among men with high-risk localized or locally advanced prostate cancer (HRLPC) treated with radical radiotherapy (RT) or radical prostatectomy (RP).

MATERIAL AND METHODS

Men diagnosed with HRLPC in 2006-2020, who received primary RT or RP, were identified from the Prostate Cancer data Base Sweden (PCBaSe) 5.0. Follow-up ended on 30 June 2021. Treatment trajectories and risk of death from prostate cancer (PCa) or other causes were assessed by competing risk analyses using cumulative incidence for each event.

RESULTS

In total, 8317 men received RT and 4923 men underwent RP. The median (interquartile range) follow-up was 6.2 (3.6-9.5) years. After RT, the 10-year risk of PCa-related death was 0.13 (95% confidence interval [CI] 0.12-0.14) and the risk of death from all causes was 0.32 (95% CI 0.31-0.34). After RP, the 10-year risk of PCa-related death was 0.09 (95% CI 0.08-0.10) and the risk of death from all causes was 0.19 (95% CI 0.18-0.21). The 10-year risks of androgen deprivation therapy (ADT) as secondary treatment were 0.42 (95% CI 0.41-0.44) and 0.21 (95% CI 0.20-0.23) after RT and RP, respectively. Among men who received ADT as secondary treatment, the risk of PCa-related death at 10 years after initiation of ADT was 0.33 (95% CI 030-0.36) after RT and 0.27 (95% CI 0.24-0.30) after RP.

CONCLUSION

Approximately one in 10 men with HRLPC who received primary RT or RP had died from PCa 10 years after diagnosis. Approximately one in three men who received secondary ADT, an indication of PCa progression, died from PCa 10 years after the start of ADT. Early identification and aggressive treatment of men with high risk of progression after radical treatment are warranted.

Using the Cell-Cycle Risk Score to Predict the Benefit of Androgen-Deprivation Therapy Added to Radiation Therapy in Patients With Newly Diagnosed Prostate Cancer

PURPOSE

Guidelines recommend adding androgen-deprivation therapy (ADT) to radiation therapy (RT) in certain patients with localized prostate cancer. Individualized genomic testing may improve the prognostic accuracy of risk assessments. Herein, we describe a mathematical model of the benefit of adding ADT to RT as a function of the personalized clinical cell-cycle risk (CCR) score to inform 10-year metastasis risk.

METHODS

A model of absolute risk reduction (ARR) was built using a retrospective cohort of men tested with Prolaris who received RT alone (N = 467). The relative benefit of ADT added to RT to reduce distant metastasis was estimated at 41% on the basis of a meta-analysis of randomized trials. The ARR and number needed to treat (NNT) were computationally derived in patients clinically tested with Prolaris between January 1, 2020, and October 31, 2022 (N = 56,485). Risks were predicted using a cause-specific Cox proportional hazards model with CCR score predicting time to metastasis. A CCR score of 2.112 represents the validated multimodal treatment (MMT) threshold.

RESULTS

The ARR from ADT increased from almost zero at low CCR scores to 17.1% at CCR = 3.690 with the corresponding NNT = 6, indicating that adding ADT to RT would prevent metastasis within 10 years for one of every six treated individuals. In the clinical cohort, the average ARR was 0.86% in individuals under the MMT threshold (NNT = 116). The average ARR was 8.19% in individuals above the MMT threshold (NNT = 12). Broad ranges of ADT benefit were observed within National Comprehensive Cancer Network risk categories.

CONCLUSION

The precise and personalized risk estimate of metastasis provided by the CCR score can help inform patients and physicians when considering treatment intensification.

The effect of dose-escalation radiotherapy with simultaneous-integrated-boost on the use of short-term androgen deprivation therapy in patients with intermediate risk prostate cancer

PURPOSE

To compare the biochemical failure (FFBF) and prostate cancer specific survival (PCSS) rates of patients with intermediate-risk prostate cancer (IR-PC) who were treated with 6 months of androgen deprivation therapy (ADT) with 78 Gy to the prostate, those treated with ADT and focal boost (FB) of 86 Gy to intraprostatic lesion (IPL) using the simultaneous-integrated boost (SIB) technique, and those treated with SIB alone.

MATERIALS AND METHODS

A retrospective analysis of 320 IR-PC patients treated between January 2012 and April 2021 was performed. Patients were divided into three groups based on their treatment arm: 78 + ADT (109 patients, 34.1%), 78/86 (102 patients, 31.8%), and 78/86 + ADT. Univariable and multivariable analyses were used to determine prognostic factors for FFBF and PCSS.

RESULTS

Median follow-up was 8.8 years. The 8-year FFBF and PCSS rates were 88.6% and 99.0%. Patients who received ADT had significantly higher pretreatment PSA levels and clinical tumor stage. Disease progression occurred in 45 patients (7.3%) at a median of 41.9 months after definitive radiotherapy (RT). Younger age, positive core biopsy (PCB) ≥ 50%, and the absence of ADT were all independent predictors of poor FFBF in multivariate analysis, whereas patients with PCB < 50% who were also given ADT had better PCSS. Patients treated with 78/86 Gy alone had worse FFBF than those treated with 78 Gy and ADT (Hazard ratio [HR] = 3.39 [95% CI = 1.46-7.88]; p = 0.005), as well as than those treated with 78/86 Gy and ADT (HR = 3.21 [95% CI = 1.23-6.46]; p = 0.009). However, FB to IPL has no effect on PCSS in multivariable analysis. There was no significant difference between treatment groups in terms of acute and late Grade ≥2 genitourinary or gastrointestinal toxicity.

CONCLUSIONS

Our findings demonstrated that patients who received 78/86 alone did worse than patients who received ADT with either 78 or 78/86 Gy. However, because IR-PC patients are so diverse, additional prospective trials are needed to validate our findings.

Risk of prostate cancer death after radical radiotherapy with neoadjuvant and adjuvant therapy with bicalutamide or gonadotropin-releasing hormone agonists

BACKGROUND

Oncological outcome after radical radiotherapy (RRT) combined with neoadjuvant and adjuvant androgen suppression therapy (AST) may differ according to type of AST. The aim of this nationwide register-based study was to investigate risk of prostate cancer (Pca) death after different neoadjuvant and adjuvant ASTs; (i) bicalutamide, (ii) gonadotropin-releasing hormone agonists (GnRH) or (iii) combined bicalutamide and GnRH (CAB), together with RRT.

MATERIALS AND METHODS

Data for 6882 men diagnosed with high-risk Pca between 2007 and 2020 and treated with primary RRT was retrieved from Prostate Cancer data Base Sweden (PCBaSe) 5.0. Time to Pca death according to type of neoadjuvant and adjuvant AST was assessed by use of Kaplan-Meier plots and Cox proportional hazard models adjusted for putative confounders.

RESULTS

Data were stratified by RRT type since the effect of AST in risk of Pca death differed according to type of RRT. Compared with the reference RRT combined with neoadjuvant CAB/adjuvant GnRH, risk of Pca death for men treated with CAB/bicalutamide and conventionally fractionated external beam radiotherapy (CF-EBRT) was hazard ratio (HR) 0.73 (95% CI: 0.50-1.04), hypofractionated EBRT (HF-EBRT), HR 1.35 (95% CI: 0.65-2.81) and EBRT with high dose rate brachytherapy (EBRT-HDRBT), HR 0.85 (95% CI: 0.37-1.95). Risk of Pca death for men treated with bicalutamide/bicalutamide and: (i) CF-EBRT was HR 2.35 (95% CI: 1.42-3.90), (ii) HF-EBRT, HR 0.70 (95% CI: 0.26-1.85), (iii) HF-EBRT, HR 4.07 (95% CI: 1.88-8.77) vs the reference.

CONCLUSION

In this observational study, risk of Pca death between men receiving different combinations of AST varied according to RRT type. No difference was found in risk of Pca death for men treated with bicalutamide or GnRH as adjuvant therapy to RRT following neoadjuvant CAB. Risk of Pca death was increased for men with monotherapy neo-/adjuvant bicalutamide in combination with CF-EBRT or EBRT-HDRBT.

Novel Approaches in the Systemic Management of High-Risk Prostate Cancer

Locally advanced prostate cancer comprises approximately 20% of new prostate cancer diagnoses. For these patients, international guidelines recommend treatment with radiotherapy (RT) to the prostate in combination with long-term (2-3 years) androgen deprivation therapy (ADT), or radical prostatectomy in combination with extended pelvic lymph node dissection (PLND) as another treatment option for selected patients as part of multimodal therapy. Improvements in overall survival with docetaxel or an androgen receptor signaling inhibitor have been achieved in patients with metastatic castration sensitive or castration resistant prostate cancer. However, the role of systemic therapy combinations for high risk and/or unfavorable prostate cancer is unclear. In this context, the aim of this review is to assess the current evidence for systemic treatment combinations as part of primary definitive therapy in patients with high-risk localized prostate cancer.

Association of PSA kinetics after testosterone recovery with subsequent recurrence: secondary analysis of a phase III randomized controlled trial

PURPOSE

After cessation of androgen deprivation therapy (ADT), testosterone gradually recovers to supracastrate levels (> 50 ng/dL). After this, rises in prostate-specific antigen (PSA) are often seen. However, it remains unknown whether early PSA kinetics after testosterone recovery are associated with subsequent biochemical recurrence (BCR).

METHODS

We performed a secondary analysis of a phase III randomized controlled trial in which newly diagnosed localized prostate cancer patients were randomly allocated to ADT for 6 months starting 4 months prior to or simultaneously with prostate RT. We calculated the PSA doubling time (PSADT) based on PSA values up to 18 months after supracastrate testosterone recovery. Competing risk regression was used to evaluate the association of PSADT with relative incidence of BCR, considering deaths as competing events.

RESULTS

Overall, 313 patients were eligible. Median PSADT was 8 months. Cumulative incidence of BCR at 10 years from supracastrate testosterone recovery was 19% and 11% in patients with PSADT < 8 months and ≥ 8 months (p = 0.03). Compared to patients with PSADT of < 4 months, patients with higher PSADT (sHR for PSADT 4 to < 8 months: 0.36 [95% CI 0.16-0.82]; 8 to < 12 months: 0.26 [0.08-0.91]; ≥ 12 months: 0.20 [0.07-0.56]) had lower risk of relative incidence of BCR.

CONCLUSIONS

Early PSA kinetics, within 18 months of recovery of testosterone to a supracastrate level, can predict for subsequent BCR. Taking account of early changes in PSA after testosterone recovery may allow for recognition of potential failures earlier in the disease course and thereby permit superior personalization of treatment.

Impact of sequencing of androgen receptor-signaling inhibition and radiotherapy in prostate cancer: importance of homologous recombination disruption

PURPOSE

The synergy of combining androgen receptor-signaling inhibition (ARSI) to radiotherapy (RT) in prostate cancer has been largely attributed to non-homologous end joining (NHEJ) inhibition. However, this mechanism is unlikely to explain recently observed trial results that demonstrated the sequencing of ARSI and RT significantly impacts clinical outcomes, with adjuvant ARSI following RT yielding superior outcomes to neoadjuvant/concurrent therapy. We hypothesized this is driven by differential effects on AR-signaling and alternative DNA repair pathway engagement based on ARSI/RT sequencing.

METHODS

We explored the effects of ARSI sequencing with RT (neoadjuvant vs concurrent vs adjuvant) in multiple prostate cancer cell lines using androgen-deprived media and validation with the anti-androgen enzalutamide. The effects of ARSI sequencing were measured with clonogenic assays, AR-target gene transcription and translation quantification, cell cycle analysis, DNA damage and repair assays, and xenograft animal validation studies.

RESULTS

Adjuvant ARSI after RT was significantly more effective at killing colony forming cells and decreasing the transcription and translation of downstream AR-target genes across all prostate cancer models evaluated. These results were reproduced in xenograft studies. The differential effects of ARSI sequencing were not fully explained by NHEJ inhibition alone, but by the additional disruption of homologous recombination specifically with adjuvant sequencing of ARSI.

CONCLUSION

We demonstrate that altered sequencing of ARSI and RT mediates differential anti-AR-signaling and anti-cancer effects, with the greatest benefit from adjuvant ARSI following RT. These results, combined with our prior clinical findings, support the superiority of an adjuvant-based sequencing approach when using ARSI with RT.

Biochemical Recurrence Surrogacy for Clinical Outcomes After Radiotherapy for Adenocarcinoma of the Prostate

PURPOSE

The surrogacy of biochemical recurrence (BCR) for overall survival (OS) in localized prostate cancer remains controversial. Herein, we evaluate the surrogacy of BCR using different surrogacy analytic methods.

MATERIALS AND METHODS

Individual patient data from 11 trials evaluating radiotherapy dose escalation, androgen deprivation therapy (ADT) use, and ADT prolongation were obtained. Surrogate candidacy was assessed using the Prentice criteria (including landmark analyses) and the two-stage meta-analytic approach (estimating Kendall's tau and the R2). Biochemical recurrence-free survival (BCRFS, time from random assignment to BCR or any death) and time to BCR (TTBCR, time from random assignment to BCR or cancer-specific deaths censoring for noncancer-related deaths) were assessed.

RESULTS

Overall, 10,741 patients were included. Dose escalation, addition of short-term ADT, and prolongation of ADT duration significantly improved BCR (hazard ratio [HR], 0.71 [95% CI, 0.63 to 0.79]; HR, 0.53 [95% CI, 0.48 to 0.59]; and HR, 0.54 [95% CI, 0.48 to 0.61], respectively). Adding short-term ADT (HR, 0.91 [95% CI, 0.84 to 0.99]) and prolonging ADT (HR, 0.86 [95% CI, 0.78 to 0.94]) significantly improved OS, whereas dose escalation did not (HR, 0.98 [95% CI, 0.87 to 1.11]). BCR at 48 months was associated with inferior OS in all three groups (HR, 2.46 [95% CI, 2.08 to 2.92]; HR, 1.51 [95% CI, 1.35 to 1.70]; and HR, 2.31 [95% CI, 2.04 to 2.61], respectively). However, after adjusting for BCR at 48 months, there was no significant treatment effect on OS (HR, 1.10 [95% CI, 0.96 to 1.27]; HR, 0.96 [95% CI, 0.87 to 1.06] and 1.00 [95% CI, 0.90 to 1.12], respectively). The patient-level correlation (Kendall's tau) for BCRFS and OS ranged between 0.59 and 0.69, and that for TTBCR and OS ranged between 0.23 and 0.41. The R2 values for trial-level correlation of the treatment effect on BCRFS and TTBCR with that on OS were 0.563 and 0.160, respectively.

CONCLUSION

BCRFS and TTBCR are prognostic but failed to satisfy all surrogacy criteria. Strength of correlation was greater when noncancer-related deaths were considered events.

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.

The oncologic and safety outcomes of low-dose-rate brachytherapy for the treatment of prostate cancer

Around 40 years have passed since a modern low-dose-rate (LDR) brachytherapy for prostate cancer was introduced. LDR brachytherapy has become one of the definitive treatment options besides radical prostatectomy (RP) and external beam radiation therapy (EBRT). LDR brachytherapy has several advantages over EBRT such as a higher prescribed dose to the prostate gland while avoiding unnecessary irradiation of organs at risk, a precipitous dose gradient, a brief treatment time, and a short hospital stay. Previous reports revealed that the long-term oncologic outcomes of LDR brachytherapy are superior to those of EBRT. The oncologic outcomes of low- to intermediate-risk patients are equivalent to those of RP using the recurrence definition of surgery of prostate specific antigen (PSA) >0.2 ng/mL, while the oncologic outcomes of LDR brachytherapy as tri-modality (combined EBRT and androgen deprivation therapy) for high-risk patients is superior to that of RP using the recurrence definition of surgery. In respect of toxicity, urinary disorders such as urgency and frequency are often observed after the acute phase of treatment, but these events usually resolve, while the quality of life of urinary continence is well preserved for a long time. Erectile function decreases yearly, but is relatively preserved compared to RP. In conclusion, the most noteworthy strength of LDR brachytherapy for low- to intermediate-risk patients is the "brief treatment time" that provides long recurrence-free survival, while that for high-risk patients who received LDR brachytherapy (tri-modality) is "excellent disease control."

Parp Inhibitors and Radiotherapy: A New Combination for Prostate Cancer (Systematic Review)

PARPi, in combination with ionizing radiation, has demonstrated the ability to enhance cellular radiosensitivity in different tumors. The rationale is that the exposure to radiation leads to both physical and biochemical damage to DNA, prompting cells to initiate three primary mechanisms for DNA repair. Two double-stranded DNA breaks (DSB) repair pathways: (1) non-homologous end-joining (NHEJ) and (2) homologous recombination (HR); and (3) a single-stranded DNA break (SSB) repair pathway (base excision repair, BER). In this scenario, PARPi can serve as radiosensitizers by leveraging the BER pathway. This mechanism heightens the likelihood of replication forks collapsing, consequently leading to the formation of persistent DSBs. Together, the combination of PARPi and radiotherapy is a potent oncological strategy. This combination has proven its efficacy in different tumors. However, in prostate cancer, there are only preclinical studies to support it and, recently, an ongoing clinical trial. The objective of this paper is to perform a review of the current evidence regarding the use of PARPi and radiotherapy (RT) in PCa and to give future insight on this topic.

Neoadjuvant versus Concurrent Androgen Deprivation Therapy in Localized Prostate Cancer Treated with Radiotherapy: A Systematic Review of the Literature

BACKGROUND

There is an ongoing debate on the optimal sequencing of androgen deprivation therapy (ADT) and radiotherapy (RT) in patients with localized prostate cancer (PCa). Recent data favors concurrent ADT and RT over the neoadjuvant approach.

METHODS

We conducted a systematic review in PubMed, EMBASE, and Cochrane Databases assessing the combination and optimal sequencing of ADT and RT for Intermediate-Risk (IR) and High-Risk (HR) PCa.

FINDINGS

Twenty randomized control trials, one abstract, one individual patient data meta-analysis, and two retrospective studies were selected. HR PCa patients had improved survival outcomes with RT and ADT, particularly when a long-course Neoadjuvant-Concurrent-Adjuvant ADT was used. This benefit was seen in IR PCa when adding short-course ADT, although less consistently. The best available evidence indicates that concurrent over neoadjuvant sequencing is associated with better metastases-free survival at 15 years. Although most patients had IR PCa, HR participants may have been undertreated with short-course ADT and the absence of pelvic RT. Conversely, retrospective data suggests a survival benefit when using the neoadjuvant approach in HR PCa patients.

INTERPRETATION

The available literature supports concurrent ADT and RT initiation for IR PCa. Neoadjuvant-concurrent-adjuvant sequencing should remain the standard approach for HR PCa and is an option for IR PCa.

Dose-Escalated Radiotherapy Alone or in Combination With Short-Term Androgen Deprivation for Intermediate-Risk Prostate Cancer: Results of a Phase III Multi-Institutional Trial

PURPOSE

It remains unknown whether or not short-term androgen deprivation (STAD) improves survival among men with intermediate-risk prostate cancer (IRPC) treated with dose-escalated radiotherapy (RT).

METHODS

The NRG Oncology/Radiation Therapy Oncology Group 0815 study randomly assigned 1,492 patients with stage T2b-T2c, Gleason score 7, or prostate-specific antigen (PSA) value >10 and ≤20 ng/mL to dose-escalated RT alone (arm 1) or with STAD (arm 2). STAD was 6 months of luteinizing hormone-releasing hormone agonist/antagonist therapy plus antiandrogen. RT modalities were external-beam RT alone to 79.2 Gy or external beam (45 Gy) with brachytherapy boost. The primary end point was overall survival (OS). Secondary end points included prostate cancer-specific mortality (PCSM), non-PCSM, distant metastases (DMs), PSA failure, and rates of salvage therapy.

RESULTS

Median follow-up was 6.3 years. Two hundred nineteen deaths occurred, 119 in arm 1 and 100 in arm 2. Five-year OS estimates were 90% versus 91%, respectively (hazard ratio [HR], 0.85; 95% CI, 0.65 to 1.11]; P = .22). STAD resulted in reduced PSA failure (HR, 0.52; P <.001), DM (HR, 0.25; P <.001), PCSM (HR, 0.10; P = .007), and salvage therapy use (HR, 0.62; P = .025). Other-cause deaths were not significantly different (P = .56). Acute grade ≥3 adverse events (AEs) occurred in 2% of patients in arm 1 and in 12% for arm 2 (P <.001). Cumulative incidence of late grade ≥3 AEs was 14% in arm 1 and 15% in arm 2 (P = .29).

CONCLUSION

STAD did not improve OS rates for men with IRPC treated with dose-escalated RT. Improvements in metastases rates, prostate cancer deaths, and PSA failures should be weighed against the risk of adverse events and the impact of STAD on quality of life.

Effect of Neoadjuvant Hormonal Therapy on the Postoperative Course for Patients Undergoing Robot-Assisted Radical Prostatectomy

OBJECTIVES

Neoadjuvant hormonal therapy (NHT) preceding robot-assisted radical prostatectomy (RARP) may be beneficial in high-risk cases to facilitate surgical resection. Yet, its improvement in local tumor control is not obvious. Its benefit regarding overall cancer survival is also not evident, and it may worsen sexual and hormonal functions. This study explores the effect of NHT on the perioperative course after RARP.

METHODS

In this study, 500 patients from a tertiary referral center who underwent RARP by a specialized surgeon were retrospectively included. Patients were divided into two groups: the NHT (n = 55, 11%) group, which included patients who received NHT (median: 1 month prior to RARP), and the standard non-NHT (NNHT) group (n = 445, 89%). Demographic and perioperative data were analyzed. Postoperative results, complications, and readmission rates were compared between the groups.

RESULTS

NHT patients were heterogeneous from the rest regarding cancer parameters such as PSA (25 vs. 7.8 ng/mL) and tumor risk stratification, and they were more comorbid (p = 0.006 for the ASA score). They also received fewer nerve-sparing procedures (14.5% vs. 80.4%), while the operation time was similar. Positive surgical margins (PSM) (21.8% vs. 5.4%) and positive lymph nodes (PLN) (56.4% vs. 12.7%) were significantly higher in the NHT group compared to the non-NHT (NNHT) group. Hospital stay was equal, whereas catheter days were 3 days longer in the NHT group. NHT patients also suffered more minor vesicourethral-anastomosis-related complications. Major complications (p = 0.825) and readmissions (p = 0.070) did not differ between groups.

CONCLUSION

Patients receiving NHT before RARP did not experience more major complications or readmissions within 90 days after surgery. Patients with unfavorable, high-risk tumors may benefit from NHT since it facilitates surgical resection. Randomized controlled trials are necessary to measure the advantages and disadvantages of NHT.

Are high-risk prostate cancer patients being treated equally? The impact of PSA

BACKGROUND

Patients with high-risk (HR) prostate cancer (PCa) represent a heterogeneous group, however, current treatment guidelines do not consider their specific features. The objective of this study was to evaluate treatment trends and outcomes in HR patients defined by PSA alone and otherwise low-risk features.

METHODS

Using the National Cancer Database, we identified patients diagnosed with HR PCa between 2010 and 2016. A study group of patients defined by PSA >20 ng/ml alone and otherwise low-risk features, was compared to a group of HR patients defined by Gleason score or stage. We compared treatment rates over time, the use of concomitant androgen deprivation therapy (ADT), and overall survival (OS). Examination of treatment trends was done using a Z-test analysis. A Kaplan-Meier survival analysis was used to determine 5-year OS with the Log-rank test for comparison. Statistical analyses were completed using R Version 3.5.2.

RESULTS

We identified 5,652 patients in the study group and 71,922 in the comparison group. Only 6.8% of the study group had disease ≥cT2, compared to 43.7% in the comparison group. In the study group, 12.5% (709), underwent active surveillance (AS), 36.4% (2,055) radiation therapy (EBRT) and 51.1% (2,888) radical prostatectomy (RP), while the rate of AS, EBRT, and RP in the comparison group were 0.3% (191), 43.0% (30,928), and 56.7% (40,803), respectively. Over the study period, adoption of AS increased from 6.2% in 2010 to 25.0% in 2016 in the study group (P< 0.001), but not in the comparison group. In patients undergoing EBRT, ADT treatment increased from 2010 to 2016 in both groups, though by 2016 only 45.3% of patients in the study group and 86.3% in the comparison group received ADT. The 5-year OS was 93.7% (95% CI 92.8-94.6) in the study group and 89.7% (95% CI 89.2-90.1) in the comparison group (P< 0.001).

CONCLUSIONS

Men with HR PCa defined by PSA with otherwise low risk features present at an earlier stage and receive less aggressive therapy than other HR patients. Despite increased rates of AS and decreased use of ADT, these patients appear to have improved survival when compared to other HR patients. These findings suggest that not all HR patients will benefit from aggressive definitive treatment.

Sequencing of Androgen-Deprivation Therapy of Short Duration With Radiotherapy for Nonmetastatic Prostate Cancer (SANDSTORM): A Pooled Analysis of 12 Randomized Trials

PURPOSE

The sequencing of androgen-deprivation therapy (ADT) with radiotherapy (RT) may affect outcomes for prostate cancer in an RT-field size-dependent manner. Herein, we investigate the impact of ADT sequencing for men receiving ADT with prostate-only RT (PORT) or whole-pelvis RT (WPRT).

MATERIALS AND METHODS

Individual patient data from 12 randomized trials that included patients receiving neoadjuvant/concurrent or concurrent/adjuvant short-term ADT (4-6 months) with RT for localized disease were obtained from the Meta-Analysis of Randomized trials in Cancer of the Prostate consortium. Inverse probability of treatment weighting (IPTW) was performed with propensity scores derived from age, initial prostate-specific antigen, Gleason score, T stage, RT dose, and mid-trial enrollment year. Metastasis-free survival (primary end point) and overall survival (OS) were assessed by IPTW-adjusted Cox regression models, analyzed independently for men receiving PORT versus WPRT. IPTW-adjusted Fine and Gray competing risk models were built to evaluate distant metastasis (DM) and prostate cancer-specific mortality.

RESULTS

Overall, 7,409 patients were included (6,325 neoadjuvant/concurrent and 1,084 concurrent/adjuvant) with a median follow-up of 10.2 years (interquartile range, 7.2-14.9 years). A significant interaction between ADT sequencing and RT field size was observed for all end points (P interaction < .02 for all) except OS. With PORT (n = 4,355), compared with neoadjuvant/concurrent ADT, concurrent/adjuvant ADT was associated with improved metastasis-free survival (10-year benefit 8.0%, hazard ratio [HR], 0.65; 95% CI, 0.54 to 0.79; P < .0001), DM (subdistribution HR, 0.52; 95% CI, 0.33 to 0.82; P = .0046), prostate cancer-specific mortality (subdistribution HR, 0.30; 95% CI, 0.16 to 0.54; P < .0001), and OS (HR, 0.69; 95% CI, 0.57 to 0.83; P = .0001). However, in patients receiving WPRT (n = 3,049), no significant difference in any end point was observed in regard to ADT sequencing except for worse DM (HR, 1.57; 95% CI, 1.20 to 2.05; P = .0009) with concurrent/adjuvant ADT.

CONCLUSION

ADT sequencing exhibits a significant impact on clinical outcomes with a significant interaction with field size. Concurrent/adjuvant ADT should be the standard of care where short-term ADT is indicated in combination with PORT.

Cardiovascular toxicities of androgen deprivation therapy in Asian men with localized prostate cancer after curative radiotherapy: a registry-based observational study

Background

Androgen deprivation therapy (ADT) and radiotherapy (RT) are the mainstay treatment for localized prostate cancer and recurrence after surgery. Cardiovascular (CV) toxicity of ADT is increasingly recognized, and the risk relates to pre-existing risk factors and ADT modalities. Despite ethnic differences in the prevalence of CV risk factors and variations of CV mortality, data on ADT-related cardiotoxicities in the Asian population remain inconclusive. Our registry-based study investigated ADT-related major adverse cardiovascular events (MACE) after primary or salvage RT.

Methods

Our study combined two prospectively established registry databases from National Cancer Center Singapore and National Heart Center Singapore. The primary endpoint is time to first MACE after treatment. MACE is defined as myocardial infarction, stroke, unstable angina, or cardiovascular death. Two types of propensity score adjustments, including ADT propensity score as a covariate in the multivariable regression model and propensity score weighting, were applied to balance baseline features and CV risk factors between RT alone and RT + ADT groups.

Results

From 2000 to 2019, 1940 patients received either RT alone (n = 494) or RT + ADT (n = 1446) were included. After a median follow-up of 10 years (RT) and 7.2 years (RT+ ADT), the cumulative incidence of MACE at 1, 3 and 9 years was 1.2, 5 and 16.2% in RT group, and 1.1, 5.2 and 17.6% in RT + ADT group, respectively. There were no differences in the incidence of MACE between 2 groups (HR 1.01, 95% CI 0.78–1.30, p = 0.969). Pre-treatment CV risk factors were common (80%), and CV disease (15.9%) was the second leading cause of death after prostate cancer (21.1%). On univariate analysis, older age, Indians and Malays, pre-existing CV risk factors, and history of MACE were associated with higher MACE risk. After propensity score adjustments, there remained no significant differences in MACE risk between RT + ADT and RT group on multivariable analysis.

Conclusions

In our registry-based study, ADT is not associated with increased risk of major cardiovascular events among Southeast Asian men with prostate cancer after curative radiotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40959-022-00131-4.

Androgen Metabolism and Response in Prostate Cancer Anti-Androgen Therapy Resistance

All aspects of prostate cancer evolution are closely related to androgen levels and the status of the androgen receptor (AR). Almost all treatments target androgen metabolism pathways and AR, from castration-sensitive prostate cancer (CSPC) to castration-resistant prostate cancer (CRPC). Alterations in androgen metabolism and its response are one of the main reasons for prostate cancer drug resistance. In this review, we will introduce androgen metabolism, including how the androgen was synthesized, consumed, and responded to in healthy people and prostate cancer patients, and discuss how these alterations in androgen metabolism contribute to the resistance to anti-androgen therapy.

Local Failure Events in Prostate Cancer Treated with Radiotherapy: A Pooled Analysis of 18 Randomized Trials from the Meta-analysis of Randomized Trials in Cancer of the Prostate Consortium (LEVIATHAN)

CONTEXT

The prognostic importance of local failure after definitive radiotherapy (RT) in National Comprehensive Cancer Network intermediate- and high-risk prostate cancer (PCa) patients remains unclear.

OBJECTIVE

To evaluate the prognostic impact of local failure and the kinetics of distant metastasis following RT.

EVIDENCE ACQUISITION

A pooled analysis was performed on individual patient data of 12 533 PCa (6288 high-risk and 6245 intermediate-risk) patients enrolled in 18 randomized trials (conducted between 1985 and 2015) within the Meta-analysis of Randomized Trials in Cancer of the Prostate Consortium. Multivariable Cox proportional hazard (PH) models were developed to evaluate the relationship between overall survival (OS), PCa-specific survival (PCSS), distant metastasis-free survival (DMFS), and local failure as a time-dependent covariate. Markov PH models were developed to evaluate the impact of specific transition states.

EVIDENCE SYNTHESIS

The median follow-up was 11 yr. There were 795 (13%) local failure events and 1288 (21%) distant metastases for high-risk patients and 449 (7.2%) and 451 (7.2%) for intermediate-risk patients, respectively. For both groups, 81% of distant metastases developed from a clinically relapse-free state (cRF state). Local failure was significantly associated with OS (hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.06-1.30), PCSS (HR 2.02, 95% CI 1.75-2.33), and DMFS (HR 1.94, 95% CI 1.75-2.15, p < 0.01 for all) in high-risk patients. Local failure was also significantly associated with DMFS (HR 1.57, 95% CI 1.36-1.81) but not with OS in intermediate-risk patients. Patients without local failure had a significantly lower HR of transitioning to a PCa-specific death state than those who had local failure (HR 0.32, 95% CI 0.21-0.50, p < 0.001). At later time points, more distant metastases emerged after a local failure event for both groups.

CONCLUSIONS

Local failure is an independent prognosticator of OS, PCSS, and DMFS in high-risk and of DMFS in intermediate-risk PCa. Distant metastasis predominantly developed from the cRF state, underscoring the importance of addressing occult microscopic disease. However a "second wave" of distant metastases occurs subsequent to local failure events, and optimization of local control may reduce the risk of distant metastasis.

PATIENT SUMMARY

Among men receiving definitive radiation therapy for high- and intermediate-risk prostate cancer, about 10% experience local recurrence, and they are at significantly increased risks of further disease progression. About 80% of patients who develop distant metastasis do not have a detectable local recurrence preceding it.

Drivers of Radioresistance in Prostate Cancer

Prostate cancer (PCa) is the second most commonly diagnosed cancer worldwide. Radiotherapy remains one of the first-line treatments in localised disease and may be used as monotherapy or in combination with other treatments such as androgen deprivation therapy or radical prostatectomy. Despite advancements in delivery methods and techniques, radiotherapy has been unable to totally overcome radioresistance resulting in treatment failure or recurrence of previously treated PCa. Various factors have been linked to the development of tumour radioresistance including abnormal tumour vasculature, oxygen depletion, glucose and energy deprivation, changes in gene expression and proteome alterations. Understanding the biological mechanisms behind radioresistance is essential in the development of therapies that are able to produce both initial and sustained response to radiotherapy. This review will investigate the different biological mechanisms utilised by PCa tumours to drive radioresistance.

Hypofractionated Radiotherapy in Intermediate-Risk Prostate Cancer Patients: Long-Term Results

Background: To evaluate outcomes in terms of survival and toxicity in a series of intermediate-risk prostate cancer (PCa) patients treated with hypofractionated radiotherapy (HyRT) + hormonal therapy (HT) with or without image guidance (IGRT) and to investigate the impact of different variables. Methods: This is a multi-centric study. From January 2005 to December 2019, we treated 313 intermediate-risk PCa patients (T2b−T2c, Gleason score 7, or pre-treatment PSA 10 to 20 ng/mL) with HyRT. Patients received 54.75 Gy in 15 fractions in 5 weeks plus 9 months of neo-adjuvant, concomitant, and adjuvant HT with or without IGRT. Results: Median follow-up was 91.6 months (range 5.1−167.8 months). Median OS was not reached, and the 8- and 10-year OS was 81.9% and 72.4%, respectively. Median CSS was not reached, and the 8- and 10-year CSS was 97.9% and 94.5%, respectively. PSA at first follow-up <0.8 ng/mL was significantly related to better oncological outcomes (CSS, bRFS, LRFS, cPFS, and MFS) in both univariate and multivariate analysis. After Propensity Score matching, grade 2−3 acute and cumulative late GU (p = 0.153 and p = 0.581, respectively) and GI (p = 0.196 and p = 0.925, respectively) toxicity were not statistically different in patients treated with or without IGRT. Conclusions: HyRT is effective and safe regardless of the use of IGRT. PSA at first follow-up is an easily accessible prognostic factor that may help the clinicians to identify patients who require a treatment intensification.

Characteristics of Patients in SPCG-15—A Randomized Trial Comparing Radical Prostatectomy with Primary Radiotherapy plus Androgen Deprivation Therapy in Men with Locally Advanced Prostate Cancer

Background

There is no high-grade evidence for surgery as primary treatment for locally advanced prostate cancer. The SPCG-15 study is the first randomized trial comparing surgical treatment with radiotherapy.

Objective

To describe the baseline characteristics of the first 600 randomized men in the SPCG-15 study. The study will compare mortality and functional outcomes.

Design, setting, and participants

This study is a Scandinavian prospective, open, multicenter phase III randomized clinical trial aiming to randomize 1200 men.

Intervention

Radical prostatectomy with or without consecutive radiotherapy (experimental) and radiotherapy with neoadjuvant androgen deprivation therapy (standard of care).

Outcome measurements and statistical analysis

Cause-specific survival, metastasis-free survival, overall survival, and patient-reported bowel function, sexual health, and lower urinary tract symptoms were measured.

Results and limitations

The distribution of characteristics was similar in the two study arms. The median age was 67 yr (range 45–75 yr). Among the operated men, 36% had pT3a stage of disease and 39% had pT3b stage. International Society of Urological Pathology grades 2, 3, 4, and 5 were prevalent in 21%, 35%, 7%, and 27%, respectively. Half of the men (51%) in the surgery arm had no positive lymph nodes. The main limitation is the pragmatic design comparing the best available practice at each study site leading to heterogeneity of treatment regimens within the study arms.

Conclusions

We have proved that randomization between surgery and radiotherapy for locally advanced prostate cancer is feasible. The characteristics of the study population demonstrate a high prevalence of advanced disease, well-balanced comparison groups, and a demography mirroring the Scandinavian population of men with prostate cancer at large.

Patient summary

This study, which has recruited >600 men, compares radiotherapy with surgery for prostate cancer, and an analysis at the time of randomization indicates that the study will be informative and generalizable to most men with locally advanced but not metastasized prostate cancer.

High-dose Radiotherapy or Androgen Deprivation Therapy (HEAT) as Treatment Intensification for Localized Prostate Cancer: An Individual Patient-data Network Meta-analysis from the MARCAP Consortium

BACKGROUND

The relative benefits of radiotherapy (RT) dose escalation and the addition of short-term or long-term androgen deprivation therapy (STADT or LTADT) in the treatment of prostate cancer are unknown.

OBJECTIVE

To perform a network meta-analysis (NMA) of relevant randomized trials to compare the relative benefits of RT dose escalation ± STADT or LTADT.

DESIGN, SETTING, AND PARTICIPANTS

An NMA of individual patient data from 13 multicenter randomized trials was carried out for a total of 11862 patients. Patients received one of the six permutations of low-dose RT (64 to <74 Gy) ± STADT or LTADT, high-dose RT (≥74 Gy), or high-dose RT ± STADT or LTADT.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES

Metastasis-free survival (MFS) was the primary endpoint. Frequentist and Bayesian NMAs were performed to rank the various treatment strategies by MFS and biochemical recurrence-free survival (BCRFS).

RESULTS AND LIMITATIONS

Median follow-up was 8.8 yr (interquartile range 5.7-11.5). The greatest relative improvement in outcomes was seen for addition of LTADT, irrespective of RT dose, followed by addition of STADT, irrespective of RT dose. RT dose escalation did not improve MFS either in the absence of ADT (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.80-1.18) or with STADT (HR 0.99, 95% CI 0.8-1.23) or LTADT (HR 0.94, 95% CI 0.65-1.37). According to P-score ranking and rankogram analysis, high-dose RT + LTADT was the optimal treatment strategy for both BCRFS and longer-term outcomes.

CONCLUSIONS

Conventionally escalated RT up to 79.2 Gy, alone or in the presence of ADT, does not improve MFS, while addition of STADT or LTADT to RT alone, regardless of RT dose, consistently improves MFS. RT dose escalation does provide a high probability of improving BCRFS and, provided it can be delivered without compromising quality of life, may represent the optimal treatment strategy when used in conjunction with ADT.

PATIENT SUMMARY

Using a higher radiotherapy dose when treating prostate cancer does not reduce the chance of developing metastases or death, but it does reduce the chance of having a rise in prostate-specific antigen (PSA) signifying recurrence of cancer. Androgen deprivation therapy improves all outcomes. A safe increase in radiotherapy dose in conjunction with androgen deprivation therapy may be the optimal treatment.

Androgen Deprivation therapy for Oligo-recurrent Prostate cancer in addition to radioTherapy (ADOPT): study protocol for a randomised phase III trial

Background

More than 60% of oligo-recurrent prostate cancer (PCa) patients treated with metastasis-directed radiotherapy (MDRT) develop biochemical recurrence within 2 years. This recurrence rate emphasises the need for improved treatment and patient selection. In line with the treatment of primary PCa, the efficacy of MDRT may be enhanced when combined with androgen-deprivation therapy (ADT). Furthermore, the availability of PSMA PET/CT offers an excellent tool for optimal patient selection for MDRT. This phase III randomised controlled trial will investigate the role of the addition of ADT to MDRT in oligo-recurrent PCa patients selected with PSMA PET/CT to enhance oncological outcome.

Methods

Two hundred and eighty patients will be randomised in a 1:1 ratio to the standard treatment arm (MDRT alone) or the experimental arm (MDRT + 6 months ADT). Patients with biochemical recurrence after primary treatment of PCa presenting with ≤ 4 metastases will be included. The primary endpoint is the 2.5-year metastases progression-free survival (MPFS). Secondary endpoints are acute and late toxicity, quality of life, biochemical progression-free survival, overall survival, and the sensitivity of the PSMA PET/CT for detecting oligometastases at low PSA-levels. So far, between March 2020 and December 2021, one hundred patients have been included.

Discussion

This phase III randomised controlled trial will assess the possible benefit of the addition of 6 months ADT to MDRT on metastases progression-free survival, toxicity, QoL and survival in PCa patients with 1–4 recurrent oligometastatic lesions.

Trial registration

ClinicalTrials.gov, NCT04302454. Registered 10 March 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09523-2.

The Clinical Cell-Cycle Risk (CCR) Score Is Associated With Metastasis After Radiation Therapy and Provides Guidance on When to Forgo Combined Androgen Deprivation Therapy With Dose-Escalated Radiation

PURPOSE

The clinical cell-cycle risk (CCR) score, which combines the University of California, San Francisco's Cancer of the Prostate Risk Assessment (CAPRA) and the cell cycle progression (CCP) molecular score, has been validated to be prognostic of disease progression for men with prostate cancer. This study evaluated the ability of the CCR score to prognosticate the risk of metastasis in men receiving dose-escalated radiation therapy (RT) with or without androgen deprivation therapy (ADT).

METHODS AND MATERIALS

This retrospective, multi-institutional cohort study included men with localized National Comprehensive Cancer Network (NCCN) intermediate-, high-, and very high-risk prostate cancer (N = 741). Patients were treated with dose-escalated RT with or without ADT. The primary outcome was time to metastasis.

RESULTS

The CCR score prognosticated metastasis with a hazard ratio (HR) per unit score of 2.22 (95% confidence interval [CI], 1.71-2.89; P < .001). The CCR score better prognosticated metastasis than NCCN risk group (CCR, P < .001; NCCN, P = .46), CAPRA score (CCR, P = .002; CAPRA, P = .59), or CCP score (CCR, P < .001; CCP, P = .59) alone. In bivariable analyses, CCR score remained highly prognostic when accounting for ADT versus no ADT (HR, 2.18; 95% CI, 1.61-2.96; P < .001), ADT duration as a continuous variable (HR, 2.11; 95% CI, 1.59-2.79; P < .001), or ADT given at or below the recommended duration for each NCCN risk group (HR, 2.19; 95% CI, 1.69-2.86; P < .001). Men with CCR scores below or above the multimodality threshold (CCR score, 2.112) had a 10-year risk of metastasis of 3.7% and 21.24%, respectively. Men with below-threshold scores receiving RT alone had a 10-year risk of metastasis of 3.7%, and for men receiving RT plus ADT, the 10-year risk of metastasis was also 3.7%.

CONCLUSIONS

The CCR score accurately and precisely prognosticates metastasis and adds clinically actionable information relative to guideline-recommended therapies based on NCCN risk in men undergoing dose-escalated RT with or without ADT. For men with scores below the multimodality threshold, adding ADT may not significantly reduce their 10-year risk of metastasis.

Association between medical androgen deprivation therapy and long-term cardiovascular disease and all-cause mortality in non-metastatic prostate cancer

Studies have suggested that prostate cancer (PCa) patients receiving androgen deprivation therapy (ADT) are at increased risk of developing or exacerbating cardiovascular disease (CVD). We aimed to explore the association between ADT for PCa and subsequent CVD and all‐cause mortality in this nationwide, longitudinal study. We also evaluated the role of cardiovascular risk and ADT duration to determine effect modification. Norwegian registry data were used to identify patients with PCa from 2008‐18 and who received primary ADT in the first year after diagnosis. The associations between ADT and composite cardiovascular events, and the individual components of myocardial infarction, stroke and heart failure, in addition to atrial fibrillation and all‐cause mortality, were explored using time‐varying Cox regression models. We included 30 923 PCa patients, of whom 8449 (27%) received primary ADT. Mean follow‐up was 2.9 and 3.8 years for CVD events and mortality, respectively. We found an association between ADT and composite CVD (adjusted HR 1.13: 95% CI 1.05‐1.21), myocardial infarction (1.18: 1.05‐1.32), stroke (1.21: 1.06‐1.38), heart failure (1.23: 1.13‐1.35) and all‐cause mortality (1.49: 1.39‐1.61). These associations persisted in those with low and moderate CVD risk and ADT longer than 7 months. A relationship between ADT and composite CVD and all‐cause mortality was observed, especially in those with moderate CVD risk and longer treatment duration. Future studies with more detailed cancer data are needed to verify the clinical relevance of these results, especially when considering all‐cause mortality within the context of treatment guidelines and benefits of ADT.

Stereotactic Radiation Therapy versus Brachytherapy: Relative Strengths of Two Highly Efficient Options for the Treatment of Localized Prostate Cancer

Stereotactic body radiation therapy (SBRT) has become a valid option for the treatment of low- and intermediate-risk prostate cancer. In randomized trials, it was found not inferior to conventionally fractionated external beam radiation therapy (EBRT). It also compares favorably to brachytherapy (BT) even if level 1 evidence is lacking. However, BT remains a strong competitor, especially for young patients, as series with 10-15 years of median follow-up have proven its efficacy over time. SBRT will thus have to confirm its effectiveness over the long-term as well. SBRT has the advantage over BT of less acute urinary toxicity and, more hypothetically, less sexual impairment. Data are limited regarding SBRT for high-risk disease while BT, as a boost after EBRT, has demonstrated superiority against EBRT alone in randomized trials. However, patients should be informed of significant urinary toxicity. SBRT is under investigation in strategies of treatment intensification such as combination of EBRT plus SBRT boost or focal dose escalation to the tumor site within the prostate. Our goal was to examine respective levels of evidence of SBRT and BT for the treatment of localized prostate cancer in terms of oncologic outcomes, toxicity and quality of life, and to discuss strategies of treatment intensification.

Androgen Receptor Gene Pathway Upregulation and Radiation Resistance in Oligometastatic Prostate Cancer

Stereotactic ablative body radiotherapy (SABR) is currently used as a salvage intervention for men with oligometastatic prostate cancer (PC), and increasingly so since the results of the Stereotactic Ablative Body Radiotherapy for the Comprehensive Treatment of Oligometastatic Cancers (SABR-COMET) trial reported a significant improvement in overall survival with SABR. The addition of androgen deprivation therapy (ADT) to localised prostate radiotherapy improves survival as it sensitises PC to radiotherapy-induced cell death. The importance of the androgen receptor (AR) gene pathway in the development of resistance to radiotherapy is well established. In this review paper, we will examine the data to determine how we can overcome the upregulation of the AR pathway and suggest a strategy for improving outcomes in men with oligometastatic hormone-sensitive PC.

A review of clinical evidence to assess differences in efficacy and safety of luteinizing hormone-releasing hormone (LHRH) agonist (goserelin) and LHRH antagonist (degarelix)

Luteinizing hormone-releasing hormone agonist (LHRH-A), goserelin, and antagonist, degarelix, are both indicated for the treatment of advanced prostate cancer (PCa); however, large comparative trials evaluating their efficacy and safety are lacking. In this review, we assessed the available evidence for both the drugs. Although degarelix achieves an early rapid decline in testosterone (T) and prostate-specific antigen (PSA) levels, median T and PSA levels, in addition to prostate volume and International Prostate Symptom Scores, become comparable with goserelin over the remaining treatment period. Degarelix causes no initial flare, therefore it is recommended in patients with spinal metastases or ureteric obstruction. Goserelin achieves lower PSA, improved time to progression, and better survival outcomes when administered adjunctively to radiotherapy compared with radiotherapy alone, with significant results even over long-term follow-up. The evidence supporting adjuvant degarelix use is limited. Goserelin has better injection site safety, single-step delivery, and an efficient administration schedule compared with degarelix, which has significantly higher injection site reactions and less efficient administration mechanism. There is conflicting evidence about the risk of cardiovascular disease (CVD), and caution is required when using LHRH-A in patients with preexisting CVD. There is considerable long-term evidence for goserelin in patients with advanced PCa, with degarelix being a more recent option. The available comparative evidence of goserelin versus degarelix has several inherent limitations related to study design, sample size, conduct, and statistical analyses, and hence warrants robust prospective trials and long-term follow-up.

Outcomes of intensity-modulated radiation therapy for intermediate- or high-risk prostate cancer: a single-institutional study

BACKGROUND

There are few reports from Japan about the outcomes of intensity-modulated radiation therapy for localized prostate cancer. This study was aimed at assessing the efficacy and toxicity of intensity-modulated radiation therapy in patients with intermediate- or high-risk prostate cancer.

METHODS

We conducted a review of the data, retrieved from our institutional database, of patients who had received intensity-modulated radiation therapy for localized prostate cancer at a radiation dose of 78 Gy in 39 fractions. Data of 201 patients with intermediate-risk prostate cancer and 311 patients with high-risk prostate cancer were analyzed.

RESULTS

The median follow-up period after the completion of intensity-modulated radiation therapy was 100 months (range, 24-154). The rates of cause-specific survival, overall survival, metastasis-free survival and biochemical recurrence-free survival in the intermediate-risk patients were 99, 95, 95 and 94% at 5 years and 99, 91, 90 and 86% at 8 years, respectively; the corresponding rates in the high-risk patients were 100, 97, 91 and 84% at 5 years and 96, 92, 84 and 76% at 8 years, respectively. The crude incidence of late grade 2-3 genitourinary toxicity was 28.1%, and that of late grade 3 genitourinary toxicity was 2.0%. The crude incidence of late grade 2 gastrointestinal toxicity was 5.1%, and there were no cases of late grade 3 gastrointestinal toxicity.

CONCLUSIONS

Our data demonstrated that intensity-modulated radiation therapy is effective for patients with localized intermediate-risk or high-risk prostate cancer while having minimal toxicity.

Trends in Androgen Deprivation Use in Men with Intermediate Risk Prostate Cancer Who Underwent Radiotherapy

Purpose

Until 2018, National Cancer Comprehensive Network guidelines recommended androgen deprivation therapy (ADT) for all men with intermediate-risk prostate cancer who had undergone radiation therapy. Intermediate risk was stratified as favorable and unfavorable in 2018, and ADT recommendation was limited to men with unfavorable intermediate-risk prostate cancer. Data suggesting this stratification and treatment deintensification were first published in December 2013. This study characterizes US national trends for demographic, clinical, and socioeconomic factors associated with ADT use in men with intermediate-risk prostate cancer who have undergone definitive radiation therapy.

Methods and Materials

This retrospective cohort study examined 108,185 men in the National Cancer Database who were diagnosed with intermediate-risk prostate cancer from 2004 to 2016. Temporal trends in demographic, clinical, and socioeconomic factors among men with intermediate-risk prostate cancer and associations with the use of ADT were characterized.

Results

In total, 108,185 men diagnosed with intermediate-risk prostate cancer underwent radiation therapy from 2004 to 2016. Of these men, 41.09% received ADT. Among the 60,705 men with favorable intermediate-risk prostate cancer, 32.06% received ADT. Among the 47,480 men with unfavorable intermediate-risk prostate cancer, 52.64% received ADT. On multivariate analysis, use of ADT was associated with age and year of diagnosis; being a race other than White; having government-based insurance; having a higher prostate-specific antigen level, tumor stage, and Gleason score; receiving treatment at a nonacademic center; and receiving external beam radiation therapy alone.

Conclusions

The findings highlight that ADT use is variable in men undergoing definitive radiation therapy for intermediate-risk prostate cancer, with the data suggesting that several clinical and socioeconomic disparities influence its use. The findings suggest that a significant proportion of men with favorable intermediate-risk prostate cancer receive ADT and remain candidates for treatment de-escalation, whereas a significant proportion of men with unfavorable intermediate-risk prostate cancer may be undertreated when ADT is omitted.

An Expert Review on the Combination of Relugolix with Definitive Radiation Therapy for Prostate Cancer

Androgen deprivation therapy (ADT) is an integral component in the management of prostate cancer across multiple disease states. Traditionally, luteinizing hormone-releasing hormone (LHRH) agonists constituted the backbone of ADT. However, gonadotropin-releasing hormone receptor hormone (GnRH) antagonists are also available, which offer faster testosterone suppression and reduced likelihood of ADT-related adverse effects compared to LHRH agonists, including the potential for fewer ADT-associated major cardiac events. Until recently, all forms of LHRH agonists and GnRH antagonist formulations are of parenteral administration. However, recently relugolix gained FDA approval as the first oral GnRH antagonist. Relugolix achieves faster and more complete testosterone suppression compared to an LHRH agonist. This translates to more rapid prostate-specific antigen response compared to LHRH agonists. After discontinuation of relugolix, testosterone recovers faster than after GnRH agonists or injectable GnRH antagonist therapy. Overall, these factors provide opportunities for more precisely defined ADT duration when combined with radiation therapy. The rapid onset and offset testosterone suppression with relugolix, however, may require physicians to rethink the mechanism and goals of ADT when prescribing. As an oral formulation, relugolix enables patients to avoid pain and injection site reactions, limit extra office visits for injections, and achieve a shorter duration of experiencing the side effects of castrate testosterone levels. This convenience and tolerability may enhance physicians' willingness to prescribe ADT and patients' feeling of control over their ADT course, but the potential advantages are accompanied by the risks of patients choosing to discontinue therapy to escape side effects of ADT. This article focuses on different aspects of what is known and unknown regarding the optimal use of ADT and radiation therapy, and how relugolix, due to its properties, fit into our current treatment paradigms for localized prostate cancer.

Relugolix, an oral gonadotropin-releasing hormone antagonist for the treatment of prostate cancer

Androgen deprivation therapy using gonadotropin-releasing hormone (GnRH) analogues is standard treatment for intermediate and advanced prostate cancer. GnRH agonist therapy results in an initial testosterone flare, and increased metabolic and cardiovascular risks. The GnRH antagonist relugolix is able to reduce serum testosterone levels in men with prostate cancer without inducing testosterone flare. In the HERO Phase III trial, relugolix was superior to leuprolide acetate at rapidly reducing testosterone and continuously suppressing testosterone, with faster post-treatment recovery of testosterone levels. Relugolix was associated with a 54% lower incidence of major adverse cardiovascular events than leuprolide acetate. As the first oral GnRH antagonist approved for the treatment of advanced prostate cancer, relugolix offers a new treatment option.

Membrane translocation and activation of GnRH receptor sensitize prostate cancer cells to radiation

BACKGROUND

GnRH analogs are widely used as neoadjuvant agents for radiotherapy in prostate cancer (PCa) patients, with well-documented effects in reducing tumor bulk and increasing progression-free survival. GnRH analogs act locally in the prostate by triggering apoptosis of PCa cells via activation of the GnRH receptor (GnRHR). During PCa progression, the distribution of GnRHR within the cell is altered, with reduced expression in the cell membrane and remaining sequestered in the endoplasmic reticulum. Pharmacoperone IN3 is able to relocalize GnRHR to the cell membrane. The aim of this study was to evaluate the effect of radiation on PCa cells pretreated with leuprolide, alone or in combination with IN3, as radiosensitizers.

MATERIAL AND METHODS

PC3 and human PCa primary cell cultures were treated with IN3 for 24 h, followed by different doses of leuprolide for 48 h and, finally, single doses of radiation (3, 6, and 9 Gy). After radiation, cell survival, apoptosis, cell cycle distribution, and colony growth were evaluated.

RESULTS

Radiation reduced cell survival and increased apoptosis in a dose-dependent manner. This effect was also directly related to leuprolide concentration. Pretreatment with IN3 enhanced apoptosis and decreased cell survival, also observing a higher proportion of cells arrested in G2.

CONCLUSION

Neoadjuvant leuprolide increases radiation-mediated apoptosis of PCa cells. This effect was enhanced by pretreatment with pharmacoperone IN3. Clinical use of IN3 as a radiosensitizer combined with androgen deprivation therapy to improve survival of patients with PCa remains to be evaluated.

Narrative review of management strategies and outcomes in node-positive prostate cancer

Pelvic nodal involvement is present in 13% of new prostate cancer diagnoses each year and is associated with a poor prognosis compared to localized disease. Grouped as stage IV along with distant metastatic disease, node-positive nonmetastatic patients historically received systemic therapy alone as primary treatment. This treatment paradigm has shifted as data have demonstrated that these patients may benefit from aggressive locoregional therapy and are potentially curable. There is currently a lack of randomized evidence to define the optimal management for node-positive patients. While a few trials have included node-positive patients, the majority of data are derived from large multi-institutional series or population-based series. This narrative review summarizes the current literature supporting curative-intent management strategies for patients diagnosed with nonmetastatic clinically node-positive prostate cancer (cN1M0), as well as patients found to have pathologic nodal disease at the time of surgery (pN1M0). Treatment of both scenarios requires multimodality considerations including surgery, radiation therapy (RT) and systemic therapy to minimize the risks of both locoregional and distant recurrence. Future considerations include developments in enhanced imaging and systemic therapy. Inclusion of node-positive patients on prospective, randomized trials such as NRG GU 008 is needed to enhance our understanding of optimal management strategies.

Therapeutic Sequences in the Treatment of High-Risk Prostate Cancer: Paving the Way Towards Multimodal Tailored Approaches

Various definitions are currently in use to describe high-risk prostate cancer. This variety in definitions is important for patient counseling, since predicted outcomes depend on which classification is applied to identify patient’s prostate cancer risk category. Historically, strategies for the treatment of localized high-risk prostate cancer comprise local approaches such as surgery and radiotherapy, as well as systemic approaches such as hormonal therapy. Nevertheless, since high-risk prostate cancer patients remain the group with higher-risk of treatment failure and mortality rates, nowadays, novel treatment strategies, comprising hypofractionated-radiotherapy, second-generation antiandrogens, and hadrontherapy, are being explored in order to improve their long-term oncological outcomes. This narrative review aims to report the current management of high-risk prostate cancer and to explore the future perspectives in this clinical setting.

Suppressed PLIN3 frequently occurs in prostate cancer, promoting docetaxel resistance via intensified autophagy, an event reversed by chloroquine

Lipid metabolism reprogramming is one of the adaptive events that drive tumor development and survival, and may account for resistance to chemotherapeutic drugs. Perilipins are structural proteins associated with lipophagy and lipid droplet integrity, and their overexpression is associated with tumor aggressiveness. Here, we sought to explore the role of lipid droplet-related protein perilipin-3 (PLIN3) in prostate cancer (PCa) chemotherapy. We investigated the role of PLIN3 suppression in docetaxel cytotoxic activity in PCa cell lines. Additional effects of PLIN3 depletion on autophagy-related proteins and gene expression patterns, apoptotic potential, proliferation rate, and ATP levels were examined. Depletion of PLIN3 resulted in docetaxel resistance, accompanied by enhanced autophagic flux. We further assessed the synergistic effect of autophagy suppression with chloroquine on docetaxel cytotoxicity. Inhibition of autophagy with chloroquine reversed chemoresistance of stably transfected shPLIN3 PCa cell lines, with no effect on the parental ones. The shPLIN3 cell lines also exhibited reduced Caspase-9 related apoptosis initiation. Moreover, we assessed PLIN3 expression in a series of PCa tissue specimens, were complete or partial loss of PLIN3 expression was frequently noted in 70% of the evaluated specimens. Following PLIN3 silencing, PCa cells were characterized by impaired lipophagy and acquired an enhanced autophagic response upon docetaxel-induced cytotoxic stress. Such an adaptation leads to resistance to docetaxel, which could be reversed by the autophagy blocker chloroquine. Given the frequent loss of PLIN3 expression in PCa specimens, we suggest that combination of docetaxel with chloroquine may improve the efficacy of docetaxel treatment in PLIN3-deficient cancer patients.

Short Androgen Suppression and Radiation Dose Escalation in Prostate Cancer: 12-Year Results of EORTC Trial 22991 in Patients With Localized Intermediate-Risk Disease

PURPOSE

The European Organisation for Research and Treatment of Cancer (EORTC) trial 22991 (NCT00021450) showed that 6 months of concomitant and adjuvant androgen suppression (AS) improves event- (EFS, Phoenix) and clinical disease-free survival (DFS) of intermediate- and high-risk localized prostatic carcinoma, treated by external-beam radiotherapy (EBRT) at 70-78 Gy. We report the long-term results in intermediate-risk patients treated with 74 or 78 Gy EBRT, as per current guidelines.

PATIENT AND METHODS

Of 819 patients randomly assigned between EBRT or EBRT plus AS started on day 1 of EBRT, 481 entered with intermediate risk (International Union Against Cancer TNM 1997 cT1b-c or T2a with prostate-specific antigen (PSA) ≥ 10 ng/mL or Gleason ≤ 7 and PSA ≤ 20 ng/mL, N0M0) and had EBRT planned at 74 (342 patients, 71.1%) or 78 Gy (139 patients, 28.9%). We report the trial primary end point EFS, DFS, distant metastasis-free survival (DMFS), and overall survival (OS) by intention-to-treat stratified by EBRT dose at two-sided α = 5%.

RESULTS

At a median follow-up of 12.2 years, 92 of 245 patients and 132 of 236 had EFS events in the EBRT plus AS and EBRT arm, respectively, mostly PSA relapse (48.7%) or death (45.1%). EBRT plus AS improved EFS and DFS (hazard ratio [HR] = 0.53; CI, 0.41 to 0.70; P < .001 and HR = 0.67; CI, 0.49 to 0.90; P = .008). At 10 years, DMFS was 79.3% (CI, 73.4 to 84.0) with EBRT plus AS and 72.7% (CI, 66.2 to 78.2) with EBRT (HR = 0.74; CI, 0.53 to 1.02; P = .065). With 140 deaths (EBRT plus AS: 64; EBRT: 76), 10-year OS was 80.0% (CI, 74.1 to 84.7) with EBRT plus AS and 74.3% (CI, 67.8 to 79.7) with EBRT, but not statistically significantly different (HR = 0.74; CI, 0.53 to 1.04; P = .082).

CONCLUSION

Six months of concomitant and adjuvant AS statistically significantly improves EFS and DFS in intermediate-risk prostatic carcinoma, treated by irradiation at 74 or 78 Gy. The effects on OS and DMFS did not reach statistical significance.

Patient-Reported Outcomes From a Phase 3 Randomized Controlled Trial Exploring Optimal Sequencing of Short-Term Androgen Deprivation Therapy With Prostate Radiation Therapy in Localized Prostate Cancer

PURPOSE

Two phase 3 randomized controlled trials (OTT-0101, RTOG-9413) and a meta-analysis have shown an impact of sequencing of androgen deprivation therapy (ADT) and radiation therapy on oncologic outcomes in prostate cancer (PCa). However, the impact of sequencing strategy on health-related quality of life (HR-QoL) is unclear. Here, we present the patient-reported HR-QoL outcomes from the OTT-0101 study.

METHODS AND MATERIALS

In this trial, patients with PCa with Gleason score ≤7, clinical stage T1b to T3a, and prostate-specific antigen level <30 ng/mL were randomly assigned to neoadjuvant and concurrent ADT for 6 months, starting 4 months before or concurrent with prostate radiation therapy, or concurrent and adjuvant ADT for 6 months, starting simultaneously with prostate radiation therapy. HR-QoL was assessed using European Organisation for Research and Treatment of Cancer QoL questionnaires. Time until definitive deterioration was defined as time from random allocation to the first deterioration of at least 10 points with no further improvement of ≥10 points or if the patient experienced progression, died, or dropped out after deterioration, resulting in missing data. Stratified log-rank tests were applied for between-group comparisons of time-to-event estimates.

RESULTS

Overall, 393 patients (194 and 199 in the 2 arms, respectively) were evaluable, except 214 (101 and 113 in the 2 arms, respectively) for sexual function. Five-year rates of freedom from definitive deterioration of urinary symptoms, bowel symptoms, and sexual activity were 33.5%, 33.1%, and 38.5% in the neoadjuvant group and 34.1%, 35.4%, and 36.7% in the adjuvant group, respectively, with no significant between-group differences. The adjuvant approach was associated with a reduced risk of definitive deterioration of sexual function (hazard ratio, 0.68; 95% confidence interval, 0.49-0.94; P = .02). With respect to clinical relevance, the mean change in score for sexual function showed only a small to moderate difference favoring the adjuvant group at and beyond 3 years.

CONCLUSIONS

In this study, no differences were found in the bowel or urinary symptoms between the adjuvant and neoadjuvant approach. Considering a significant likelihood of type I and type II errors and because of a lack of a persistent and clinically meaningful between-group difference in mean score changes over time, our findings do not confer a clear and conclusive picture of the impact of sequencing strategy on sexual function.