Addition of short-term androgen deprivation therapy to dose-escalated radiation therapy improves failure-free survival for select men with intermediate-risk prostate cancer

Revolutionizing localized prostate cancer treatment: Stereotactic radiotherapy "Moroccan experience"

INTRODUCTION

Prostate cancer is the most common urological cancer, and its incidence  is increasing. Radical prostatectomy and radiotherapy are theprimary treatments for localized forms. Stereotactic Body RadioTherapy (SBRT), a new and innovative therapy, has been validated for some cancer localizations but not yet for localized prostate cancer. Our study aims to report the efficacy and tolerance results of SBRT for localized prostate cancer.

MATERIALS AND METHODS

This is a retrospective study of 27 patients with localized prostate cancer (CaP) who were treated with SBRT in our department from 2017 to 2021 using transponders for tumor tracking. The dose was 36.25 Gy delivered in five fractions of 7.25 Gy. The delineation and doses of organs at risk were determined based on the recommendations of the SFRO and the TG101 report of medical physics. All patients were treated using a latest-generation linear accelerator (True Beam STXÒ).

RESULTS

Acute toxicities were observed in 33.3% of cases, with 22.2% grade 1 or 2 genitourinary (GU) and no grade 3 while 11.1% gastrointestinal (GI) toxicities were reported as grade 1-2 (7.4%) and one case grade 3 (3.7%). Late grade 1 or 2 GU toxicity was observed in 14.84% of cases, with no reports of late GI toxicity. After a 26-month follow-up period, the biochemical failure-free survival rate was 92.6%.

CONCLUSIONS

The results of our study are consistent with the existing literature and support the safety and effectiveness of SBRT as a treatment option for localized prostate cancer (CaP). In the United States, both ASTRO and the NCCN recognize SBRT as a valid treatment option for localized CaP. Ongoing phase III trials are being conducted to further substantiate these long-term results and to establish SBRT as the future standard of care for localized CaP.

Androgen Deprivation Therapy for Prostate Cancer Did Not Increase the Risk of Retinal Vascular Occlusion: A Population-Based Cohort Study

This study aimed to evaluate the effect of androgen deprivation therapy (ADT) on retinal vascular occlusion (RVO) development in patients with prostate cancer, using data from Taiwan’s National Health Insurance Research Database. A total of 1791, 1791, and 3582 patients were enrolled in the prostate cancer with ADT group, prostate cancer without ADT group, and the control group, respectively. The primary outcome was RVO occurrence, according to diagnostic codes. Cox proportional hazard regression was used to determine the adjusted hazard ratio (aHR) and 95% confidence interval (CI) of ADT and other covariates for RVO incidence. After a follow-up interval of up to 18 years, the patients with prostate cancer who received ADT showed significantly lower RVO incidence than the control group (aHR: 0.191, 95% CI: 0.059–0.621, p = 0.0059), after adjusting for multiple confounders. Hypertension was related to higher RVO incidence (aHR: 2.130, 95% CI: 1.127–4.027, p = 0.0199). Our overall results showed that using ADT for prostate cancer did not lead to a greater risk of RVO development. In fact, the patients with prostate cancer who received ADT had lower RVO incidence than those who did not receive ADT.

Acute toxicity of 4-week versus 5-week hypofractionated radiotherapy in localised prostate cancer

Aim:

To compare the acute radiation-induced bowel and bladder toxicities of two hypofractionated radiotherapy (HFRT) regimens in localised prostate cancer (PCa).

Materials and methods:

This trial consists of patients with histologically confirmed stage T1-T3aN0M0 PCa, a prostate-specific antigen concentration of 40 ng/mL or lower, and Eastern Cooperative Oncology Group performance status of 0–2. Participants were randomly assigned (1:1) to 56 Gy in 16 fractions over 4 weeks (arm A) or 70·2 Gy in 26 fractions over 5 weeks (arm B). Acute bowel and bladder toxicities were assessed using Radiation Therapy Oncology Group criteria.

Results:

Between June 2018 and December 2019, 40 patients were randomly assigned to treatment with 4-week (n = 20) and 5-week HFRT (n = 20). In the third month after completion of radiotherapy, the cumulative incidence of acute bowel and bladder toxicities of arms A and B was 20 versus 5% and 70 versus 85%, respectively. The cumulative incidence of grade 2 or worse bowel and bladder toxicities of the 5-week regimen was non-inferior to 4-week HFRT [bowel toxicity: 5% (arm A) versus 5% (arm B), bladder toxicity: 50% (arm A) versus 60% (arm B), p = 0·52).

Findings:

The 5-week regimen of HFRT is non-inferior to 4-week HFRT in terms of acute bowel and bladder toxicities.

Dose-response with stereotactic body radiotherapy for prostate cancer: A multi-institutional analysis of prostate-specific antigen kinetics and biochemical control

BACKGROUND AND PURPOSE

The optimal dose for prostate stereotactic body radiotherapy (SBRT) is still unknown. This study evaluated the dose-response relationships for prostate-specific antigen (PSA) decay and biochemical recurrence (BCR) among 4 SBRT dose regimens.

MATERIALS AND METHODS

In 1908 men with low-risk (50.0%), favorable intermediate-risk (30.9%), and unfavorable intermediate-risk (19.1%) prostate cancer treated with prostate SBRT across 8 institutions from 2003 to 2018, we examined 4 regimens (35 Gy/5 fractions [35/5, n = 265, 13.4%], 36.25 Gy/5 fractions [36.25/5, n = 711, 37.3%], 40 Gy/5 fractions [40/5, n = 684, 35.8%], and 38 Gy/4 fractions [38/4, n = 257, 13.5%]). Between dose groups, we compared PSA decay slope, nadir PSA (nPSA), achievement of nPSA ≤0.2 and ≤0.5 ng/mL, and BCR-free survival (BCRFS).

RESULTS

Median follow-up was 72.3 months. Median nPSA was 0.01 ng/mL for 38/4, and 0.17-0.20 ng/mL for 5-fraction regimens (p < 0.0001). The 38/4 cohort demonstrated the steepest PSA decay slope and greater odds of nPSA ≤0.2 ng/mL (both p < 0.0001 vs. all other regimens). BCR occurred in 6.25%, 6.75%, 3.95%, and 8.95% of men treated with 35/5, 36.25/5, 40/5, and 38/4, respectively (p = 0.12), with the highest BCRFS after 40/5 (vs. 35/5 hazard ratio [HR] 0.49, p = 0.026; vs. 36.25/5 HR 0.42, p = 0.0005; vs. 38/4 HR 0.55, p = 0.037) including the entirety of follow-up, but not for 5-year BCRFS (≥93% for all regimens, p ≥ 0.21).

CONCLUSION

Dose-escalation was associated with greater prostate ablation and PSA decay. Dose-escalation to 40/5, but not beyond, was associated with improved BCRFS. Biochemical control remains excellent, and prospective studies will provide clarity on the benefit of dose-escalation.

Multicenter Trial of Stereotactic Body Radiation Therapy for Low- and Intermediate-Risk Prostate Cancer: Survival and Toxicity Endpoints

PURPOSE

The radiobiology of prostate cancer may favor the extreme hypofractionation inherent in stereotactic body radiation therapy (SBRT); however, data from a large multicenter study are lacking. We therefore examined the hypothesis that dose-escalated SBRT can be safely administered across multiple institutions, with favorable 5-year disease-free survival (DFS) rates compared with historical controls.

METHODS AND MATERIALS

Twenty-one centers enrolled 309 patients with prostate adenocarcinoma: 172 with low-risk (LR) and 137 with intermediate-risk (IR) disease. All were treated with a non-coplanar robotic SBRT platform using real-time tracking of implanted fiducials. The prostate was prescribed 40 Gy in 5 fractions of 8 Gy. We assessed toxicities using Common Terminology Criteria for Adverse Events (CTCAE) version 3 and biochemical failure using the "nadir + 2" definition. The study population yielded 90% power to identify excessive (>10%) rates of grade ≥3 genitourinary (GU) or gastrointestinal toxicities and, in the LR group, 80% power to show superiority in DFS over a 93% historical comparison rate.

RESULTS

At a median follow-up of 61 months, 2 LR patients (1.2%) and 2 IR patients (1.5%) experienced grade 3 GU toxicities, far below the 10% toxicity rate deemed excessive (upper limits of 95% confidence interval, 3.5% and 4.3%, respectively). No grade 4 or 5 toxicities occurred. All grade 3 toxicities were GU, occurring 11 to 51 months after treatment. For the entire group, the actuarial 5-year overall survival rate was 95.6% and the DFS rate was 97.1%. The 5-year DFS rate was 97.3% for LR patients (superior to the 93% DFS rate for historical controls; P = .0008; lower limit of 95% confidence interval, 94.6%) and 97.1% for IR patients.

CONCLUSIONS

Dose-escalated prostate SBRT was administered with minimal toxicity in this multi-institutional study. Relapse rates compared favorably with historical controls. SBRT is a suitable option for LR and IR prostate cancer.

Impact of androgen-deprivation therapy on the outcome of dose-escalation prostate cancer radiotherapy without elective pelvic irradiation

The benefit of androgen-deprivation therapy (ADT) in combination with dose-escalated radiotherapy (DERT) for localized prostate cancer has not been determined in randomized studies. In this study, the benefit of ADT was assessed in patients uniformly treated with dose-escalated intensity-modulated radiation therapy (IMRT) to the prostate and seminal vesicles but not pelvis. In all, 419 patients with localized prostate adenocarcinoma underwent definitive IMRT (cumulative dose 78 Gy), with 32.6%, 33.1%, 32.1%, and 2.1% having T1 through T4 disease, respectively, and 51.2% having high-risk disease. ADT was given to 76.1% of patients. With a median follow-up of 60 months, 5-year biochemical failure-free, disease-free, and overall survival rates were 87%, 86%, and 87%, respectively. T stage was an independent predictor of all three rates. Five-year pelvic nodal recurrence rate was 2.9%. ADT improved biochemical failure-free and disease-free survival but not overall survival. ADT showed benefit in high-risk disease but not intermediate-risk disease. Late gastrointestinal and genitourinary toxicities ≥ grade 2 occurred in 11.0% and 6.7%, respectively. In conclusion, DERT with 78 Gy yields good disease control and low rate of pelvic nodal recurrence. ADT improves disease-free survival in patients with high-risk but not intermediate-risk disease.

PMH 9907: Long-term outcomes of a randomized phase 3 study of short-term bicalutamide hormone therapy and dose-escalated external-beam radiation therapy for localized prostate cancer

BACKGROUND

The role of hormone therapy (HT) with dose-escalated external-beam radiotherapy (DE-EBRT) in the treatment of intermediate-risk prostate cancer (IRPC) remains controversial. The authors report the long-term outcome of a phase 3 study of DE-EBRT with or without HT for patients with localized prostate cancer (LPC).

METHODS

From 1999 to 2006, 252 of an intended 338 patients with LPC were randomized to receive DE-EBRT with or without 5 months of neoadjuvant and concurrent bicalutamide 150 mg once daily. The study was closed early because of contemporary concerns surrounding bicalutamide. The primary outcome was biochemical failure (BF) incidence, and the secondary endpoints were overall survival (OS), local control (LC), and quality of life. The BF and OS rates were estimated using the cumulative incidence function and Kaplan-Meier methods and were compared using the Gray test and the log-rank test.

RESULTS

Eleven patients were excluded from analysis. Characteristics were well balanced in each treatment arm. Ninety-five percent of patients had IRPC. The prescribed dose increased from 75.6 grays (Gy) in 42 fractions to 78 Gy in 39 fractions over the period. At a median follow-up of 9.1 years, 98 BFs occurred, with no significant effect of HT versus no HT on the BF rate (40% vs 47%; P = .32), the OS rate (82% vs 86%; P = .37), the LC rate (52% vs 48 %; P = .32) or quality of life, in the patients who completed the questionnaires. Dose escalation to 75.6 Gy versus >75.6 Gy reduced the BF rate by 26% (P = .004).

CONCLUSIONS

For patients who predominantly have IRPC, the addition of HT to DE-EBRT did not significantly affect BF, OS, or LC. Bicalutamide appeared to be well tolerated. The conclusions from the study are limited by incomplete recruitment. Cancer 2016;122:2595-603. © 2016 American Cancer Society.

Stratification of brachytherapy-treated intermediate-risk prostate cancer patients into favorable and unfavorable cohorts

Purpose

To evaluate biochemical failure (BF) and prostate cancer specific mortality (PCSM) in intermediate-risk (IR) brachytherapy patients stratified into favorable and unfavorable cohorts, and to compare those outcomes to patients with low (LR) and high-risk (HR) disease.

Material and methods

From March 1995 till February 2012, 2,502 consecutive patients underwent permanent interstitial brachytherapy for clinically localized prostate cancer. Patients were stratified into risk groups as per the NCCN guidelines with further stratification of the intermediate risk cohort into unfavorable (primary Gleason pattern 4, ≥ 50% positive biopsies or ≥ 2 IR features) and favorable cohorts. Median follow-up was 8.5 years. The brachytherapy prescription dose was prescribed to the prostate gland with generous periprostatic margins. Biochemical failure was defined as a PSA > 0.40 ng/ml after nadir. Patients with metastatic prostate cancer or non-metastatic castrate resistant disease who died of any cause were classified as dead of prostate cancer. Multiple parameters were evaluated for effect on outcomes.

Results

Fifteen year BF for LR, favorable IR, unfavorable IR, and HR were 1.4%, 2.2%, 7.1%, and 11.1% (p < 0.001), respectively. At 15 years, PCSM for LR, favorable IR, unfavorable IR, and HR was 0.3%, 0.6%, 2.2% and 4.6% (p < 0.001), respectively. In multivariate analysis, BF was best predicted by risk group, pre-implant PSA, percent positive biopsies, prostate volume, and ADT duration, while PCSM was most closely related to risk group, percent positive biopsies and prostate volume.

Conclusions

Patients with favorable IR disease have biochemical and PCSM outcomes comparable to those of patients with LR disease. Although unfavorable IR has greater than a 3-fold increased risk of BF and PCSM when compared to favorable IR, the outcomes remain superior to those men with HR disease.

Is supplemental external beam radiation therapy essential to maximize brachytherapy outcomes in patients with unfavorable intermediate-risk disease?

PURPOSE

To evaluate whether supplemental external beam radiotherapy (EBRT) is essential to maximize Pd-103 brachytherapy outcomes in patients with unfavorable intermediate-risk (IR) disease.

METHODS AND MATERIALS

A total of 630 patients were assessed from two prospective randomized brachytherapy trials evaluating the role of supplemental EBRT in patients with higher risk features. Patients were stratified into unfavorable IR (primary Gleason pattern 4, ≥50% positive biopsies, or ≥2 IR features), favorable IR, and high-risk (HR) cohorts. Median follow-up was 7.5 years. The brachytherapy prescription dose was prescribed to the prostate gland with generous periprostatic margins. Biochemical failure (BF) was defined as a prostate-specific antigen >0.40 ng/mL after nadir. Patients with metastatic prostate cancer or nonmetastatic castrate-resistant disease who died of any cause were classified as dead of prostate cancer. Multiple parameters were evaluated for effect on outcomes.

RESULTS

The 10-year BF for favorable IR, unfavorable IR, and HR was 1.7%, 6.6%, and 15.5% (p < 0.001). At 10 years, prostate cancer-specific mortality (PCSM) and overall mortality (OM) were 0% and 20.4%, 2.1% and 23.2%, and 4.3% and 42.4% for favorable IR, unfavorable IR, and HR. Although unfavorable IR patients had a greater incidence of BF, PCSM, and OM when compared with favorable IR, neither the addition nor dose of supplemental EBRT influenced outcome.

CONCLUSIONS

Outcomes for favorable IR were superior to those with unfavorable IR. Within the confines of this study, neither the addition nor dose of supplemental EBRT influenced BF, PCSM, or OM in patients with IR disease.

[Radiotherapy in elderly patients, recommendations for the main localizations: Breast, prostate and gynaecological cancers]

Modifications of radiotherapy indications or schedules because of age could be discussed in view of a different evolution of the disease or because of specific toxicities. One important aim is to decrease the number of hospital transports. For breast cancer, the rate of local relapse after lumpectomy is lower in old patients; moreover, characteristics of the disease are often more favourable (hormonosensitivity, low grade). However, adjuvant irradiation decreases significantly the incidence of breast relapse and must be systematically proposed. Hypofractionnated schedules must be recommended; limited data are available for accelerated partial breast irradiation in old women and these techniques must not be used in routine. For low or intermediate risk prostate cancer, assessment of comorbidities is crucial before considering any invasive treatment. A life expectancy of at least 10 years is required if a curative approach, potentially toxic is proposed. In this case, radiotherapy is often the good choice, giving less sequelae than surgery. The indication of androgen deprivation must take into account cardiovascular and bone history. Management of gynaecological cancers must follow the same recommendations as in young women. Exclusive postoperative brachytherapy must be recommended in early stage endometrial carcinomas. Brachytherapy must be also systematically integrated in the radiotherapy program for cervix cancers, even in old women.

Dose-Escalated Robotic SBRT for Stage I-II Prostate Cancer

Stereotactic body radiotherapy (SBRT) is the precise external delivery of very high-dose radiotherapy to targets in the body, with treatment completed in one to five fractions. SBRT should be an ideal approach for organ-confined prostate cancer because (I) dose-escalation should yield improved rates of cancer control; (II) the unique radiobiology of prostate cancer favors hypofractionation; and (III) the conformal nature of SBRT minimizes high-dose radiation delivery to immediately adjacent organs, potentially reducing complications. This approach is also more convenient for patients, and is cheaper than intensity-modulated radiotherapy (IMRT). Several external beam platforms are capable of delivering SBRT for early-stage prostate cancer, although most of the mature reported series have employed a robotic non-coplanar platform (i.e., CyberKnife). Several large studies report 5-year biochemical relapse rates which compare favorably to IMRT. Rates of late GU toxicity are similar to those seen with IMRT, and rates of late rectal toxicity may be less than with IMRT and low-dose rate brachytherapy. Patient-reported quality of life (QOL) outcomes appear similar to IMRT in the urinary domain. Bowel QOL may be less adversely affected by SBRT than with other radiation modalities. After 5 years of follow-up, SBRT delivered on a robotic platform is yielding outcomes at least as favorable as IMRT, and may be considered appropriate therapy for stage I–II prostate cancer.

The Influence of Age and Comorbidity on the Benefit of Adding Androgen Deprivation to Dose-escalated Radiation in Men With Intermediate-risk Prostate Cancer

OBJECTIVE

Androgen deprivation therapy (ADT) can improve outcomes for men with intermediate-risk prostate cancer (IR-PrCa) receiving external-beam radiotherapy (EBRT). Older men and men with significant comorbidity may be more susceptible to the harms of ADT, therefore we aimed to determine whether these men benefit from ADT.

METHODS

The adult comorbidity evaluation-27 index categorized severity of comorbidity in 636 men treated for IR-PrCa with dose-escalated EBRT (>75 Gy). The cohort was dichotomized at median age of 70. Multivariate Cox proportional hazard analysis evaluated the association of ADT with failure-free survival (FFS) for each age and comorbidity subgroup.

RESULTS

A total of 48% of men were 70 years and above. After adjustment for tumor characteristics, the addition of ADT to EBRT was associated with improved FFS for both men below 70 years of age (adjusted hazard ratio [AHR] 0.44; 95% confidence interval [CI], 0.19-0.99; P=0.046) and men 70 years and above (AHR 0.23; 95% CI, 0.06-0.91; P=0.035). ADT improved FFS for men below 70 years who had no or mild comorbidity (AHR 0.25; 95% CI, 0.09-0.73; P=0.011) but not for men below 70 years who had moderate or severe comorbidity (AHR 1.62; 95% CI, 0.35-7.49; P=0.537). Similarly, in men 70 years and above, there was a trend for improved FFS with ADT in healthy men (AHR 0.10; 95% CI, 0.01-1.08; P=0.058) but not in men with moderate to severe comorbidity (AHR 0.38; 95% CI, 0.06-2.56; P=0.318).

CONCLUSIONS

The addition of ADT to dose-escalated EBRT can improve outcomes for both younger and older men with IR-PrCa. This benefit was more pronounced in healthy men.

Management of prostate cancer in elderly men

Elderly men comprise a large percentage of men diagnosed with prostate cancer (PrCa). Although localized PrCa is often indolent, older men tend to be diagnosed with higher-stage disease and are more likely to die from PrCa than younger men. Multiple factors other than age play an important role in determining who will benefit from active treatment, such as comorbid conditions, life expectancy, and tumor characteristics. Careful consideration of such factors can help prevent the overtreatment of elderly men with low-risk disease and undertreatment of elderly men with high-risk disease. Management decisions should be individualized by weighing the benefits of treatment against potential risks and side effects pertinent to the elderly population, whether evaluating for surgery, radiation, or androgen deprivation.