High-intermediate prostate cancer treated with low-dose-rate brachytherapy with or without androgen deprivation therapy

Comparative effectiveness of low-dose-rate brachytherapy with or without external beam radiotherapy in favorable and unfavorable intermediate-risk prostate cancer

We compared clinical outcomes associated with seed brachytherapy (SEED-BT) alone and SEED-BT plus external-beam radiotherapy (EBRT) for intermediate-risk prostate cancer using propensity score-matched analysis. From 2006 to 2011, 993 patients diagnosed with intermediate-risk were treated with either SEED-BT alone (n = 775) or SEED-BT plus EBRT (n = 158) at 3 tertiary hospitals. In the propensity score-matched analysis (102 pairs), median follow-up was 95 months (range 18–153 months). The 8-year biochemical recurrence-free rate (bRFR) was significantly better with SEED-BT alone than with combined radiotherapy (93.3% vs. 88.4%; HR 0.396; 95% CI 0.158–0.991). Grade 2 or greater late genitourinary toxicities were significantly fewer with SEED-BT alone than with combined radiotherapy (21.0% vs. 33.2%; HR 0.521; 95% CI 0.308–0.881). Similarly, grade 2 or greater late gastrointestinal toxicities were significantly fewer with SEED-BT alone (0% vs. 12.2%; HR 0.125; 95% CI 0.040–0.390). For the unfavorable intermediate-risk subgroups, SEED-BT alone yielded a significantly better bRFR than the combined radiotherapy (HR 0.325; 95% CI 0.115–0.915). SEED-BT alone might be a better disease-management plan than SEED-BT plus EBRT for intermediate-risk prostate cancer regardless of favorable and unfavorable characteristics.

After ASCENDE-RT: Biochemical and survival outcomes following combined external beam radiotherapy and low-dose-rate brachytherapy for high-risk and unfavourable intermediate-risk prostate cancer, a population-based analysis

PURPOSE

To evaluate the outcomes of unfavorable intermediate-risk (UIR) and high-risk (HR) prostate cancer patients treated with combined external beam radiation therapy (EBRT) and low-dose-rate prostate brachytherapy (LDR-PB).

METHODS AND MATERIALS

A population-based cohort of 568 prostate cancer patients treated with combined EBRT and LDR-PB from 2010 to 2016 was analyzed. All patients received EBRT followed by LDR-PB boost. Outcomes were compared with the results for the brachytherapy arm of the ASCENDE-RT trial.

RESULTS

The median followup was 4.5 years. Sixty-nine percent (N = 391) had HR disease. Ninety-four percent of the HR and 57% of UIR were treated with androgen deprivation therapy (ADT) with a median duration of 12 months. The 5-year K-M biochemical progression-free survival (b-PFS), metastasis-free survival (MFS), and overall survival (OS) were 84 ± 2%, 90 ± 2%, and 88 ± 2%, similar to 89 ± 5%, 94 ± 4%, and 92 ± 4% for the ASCENDE-RT LDR-PB arm. The likelihood of achieving a PSA ≤0.2 ng/mL at 4 years was 88%, similar to 86% in the ASCENDE-RT LDR-PB arm. Thirty-three men (5.8%) would have been ineligible for ASCENDE-RT due to high-risk features. The 5-year K-M b-PFS, MFS and OS estimates were 86 ± 2%, 92 ± 1% and 89 ± 2% for the ASCENDE-RT eligible versus 56 ± 10% (p < 0.001), 73 ± 8% (p < 0.001), and 77 ± 9% (p = 0.098) for the ineligible patients.

CONCLUSIONS

In this population-based cohort, combining LDR-PB with pelvic EBRT (+/- ADT) achieves very favorable b-PFS that compares to the LDR-PB arm of the ASCENDE-RT, supporting the generalizability of those results. Men ineligible for ASCENDE-RT, based on prognostic features, have a much higher risk of biochemical recurrence and metastatic relapse.

Outcomes of Patients With Unfavorable Intermediate-Risk Prostate Cancer Treated With External-Beam Radiotherapy Versus Brachytherapy Alone

BACKGROUND

The NCCN Guidelines for Prostate Cancer currently recommend several definitive radiotherapy (RT) options for men with unfavorable intermediate-risk (UIR) prostate cancer: external-beam RT (EBRT) plus androgen deprivation therapy (ADT) or EBRT plus brachytherapy boost with or without ADT. However, brachytherapy alone with or without ADT is not well defined and is currently not recommended for UIR prostate cancer. We hypothesized that men treated with brachytherapy with or without ADT have comparable survival rates to men treated with EBRT with or without ADT.

METHODS

A total of 31,783 men diagnosed between 2004 and 2015 with UIR prostate cancer were retrospectively reviewed from the National Cancer Database. Men were stratified into 4 groups: EBRT (n=12,985), EBRT plus ADT (n=12,960), brachytherapy (n=4,535), or brachytherapy plus ADT (n=1,303). Inverse probability of treatment weighting (IPTW) was used to adjust for covariable imbalances, and weight-adjusted multivariable analysis (MVA) using Cox regression modeling was used to compare overall survival (OS) hazard ratios (HRs).

RESULTS

Relative to EBRT alone, the following treatments were associated with improved OS: EBRT plus ADT (HR, 0.92; 95% CI, 0.87-0.97; P=.002), brachytherapy alone (HR, 0.90; 95% CI, 0.83-0.98; P=.01), and brachytherapy plus ADT (HR, 0.78; 95% CI, 0.69-0.88; P=.00006). Brachytherapy correlated with improved OS relative to EBRT in men who were not treated with ADT (HR, 0.92; 95% CI, 0.84-0.99; P=.03) and in those receiving ADT (HR, 0.84; 95% CI, 0.75-0.95; P=.004). At 10-year follow-up, 56% and 63% of men receiving EBRT and brachytherapy, respectively, were alive (P<.0001). IPTW was used to determine the average treatment effect of definitive brachytherapy. Relative to EBRT, definitive brachytherapy correlated with improved OS (HR, 0.90; 95% CI, 0.84-0.97; P=.009) on weight-adjusted MVA.

CONCLUSIONS

Definitive brachytherapy was associated with improved OS compared with EBRT. The addition of ADT to both EBRT and definitive brachytherapy was associated with improved OS. These results suggest that definitive brachytherapy should be considered as an option for men with UIR prostate cancer.

Androgen deprivation therapy and radiotherapy in intermediate-risk prostate cancer: A systematic review and meta-analysis

OBJECTIVES

Androgen deprivation therapy combined with radiotherapy for intermediate-risk prostate cancer is still a matter of debate. We conducted a meta-analysis to evaluate the necessity of androgen deprivation therapy combined with radiotherapy for intermediate-risk prostate cancer patients.

METHODS

A comprehensive literature search of articles was performed in PubMed, Embase, Cochrane library, Web of Science, Chinese National Knowledge Infrastructure, Chinese Biological Medicine, Wanfang, and VIP Databases published between February 1988 and April 2022. Studies comparing the survival of patients diagnosed with intermediate-risk prostate cancer who were treated with androgen deprivation therapy combined with radiotherapy or radiotherapy alone were included. Data were extracted and analyzed with the RevMan software (version 5.3) and the Stata software (version 17).

RESULTS

Six randomized controlled trials and nine retrospective studies, including 6853 patients (2948 in androgen deprivation therapy combined with radiotherapy group and 3905 in radiotherapy alone group) were enrolled. Androgen deprivation therapy combined with radiotherapy did not provide an overall survival (HR 1.12, 95% CI 1.01-1.12, p=0.04) or biochemical recurrence-free survival (HR 1.23, 95% CI 1.09-1.39, P=0.001) advantage to intermediate-risk prostate cancer patients.

CONCLUSION

Androgen deprivation therapy combined with radiotherapy did not show some advantages in terms of overall survival and biochemical recurrence-free survival and radiotherapy alone may be the effective therapy for intermediate-risk prostate cancer patients.

SYSTEMATIC REVIEW REGISTRATION

https://inplasy.com/inplasy-2022-8-0095/, identifier 202280095.

Does ADT benefit unfavourable intermediate risk prostate cancer patients treated with brachytherapy boost and external beam radiotherapy? A propensity-score matched analysis

PURPOSE

To investigate the role of androgen deprivation therapy (ADT) in unfavorable intermediate risk (UIR) prostate cancer patients treated with high-dose rate (HDR) brachytherapy (BT) boost.

MATERIAL AND METHODS

Data from 326 consecutive NCCN UIR prostate cancer patients treated in a single institution from 2009 to 2016 with 15 Gy HDR-BT boost plus 37.5 Gy external beam radiotherapy (EBRT) in 15 fractions to prostate and proximal seminal vesicles were retrospectively collected. Baseline information was collected and patients receiving vs. not receiving ADT were matched using a propensity-score model. Primary endpoint was biochemical-failure-free survival (BFFS). Kaplan-Meier estimates and stratified log-rank tests (adjusting for matched design) were used to compare BFFS, castration-resistance (CRFS) and metastasis free survival (MFS) outcomes between both groups.

RESULTS

A total of 326 patients were included in the analysis of which 52 ADT patients were matched to 104 non-ADT patients in a 1:2 ratio. Median follow-up was 3.4 years and 5.5 years for ADT and non-ADT respectively. No significant baseline differences were observed. ADT was used for a median total time of 6 months (interquartile range [IQR]: 4-6) and delivered a median time of 2.7 months (IQR: 1.7-4.3) prior to HDR-BT. BFFS was significantly improved in the ADT group (stratified log-rank: p = 0.043) with 3-year and 6-year BFFS of 98% and 90% for the ADT group and 92% and 82% for the non-ADT group, respectively. No significant differences were detected for CRFS or MFS.

CONCLUSION

Short-term ADT increased BFFS in UIR prostate cancer patients treated with HDR-BT boost plus EBRT.

Brachytherapy Combined With or Without Hormone Therapy for Localized Prostate Cancer: A Meta-Analysis and Systematic Review

Purpose: The purpose of this study was to evaluate the efficacy of brachytherapy combined with or without hormone therapy in patients with localized prostate cancer.

Methods and Materials: We systemically searched the Medline, Web of Science, Cochrane Library and Embase databases for studies published between the databases' dates of inception and February 2019. The primary endpoints were the 5-year overall survival (OS) rates, 5-year biochemical progression-free survival (bPFS) rates and 10-year bPFS rates. The results were expressed as the relative risk (RR) and 95% confidence interval (CI). Based on the heterogeneity evaluated with the I² statistic, a meta-analysis was performed using either a random- or fixed-effects model.

Results: A total of 16 cohort studies including 9,359 patients met all the criteria for inclusion in the analysis. Our data showed that brachytherapy (BT) combined with hormone therapy (HT) increased the patients' 5-year bPFS rates (RR = 1.04, 95% CI: 1.01–1.08, P = 0.005) and 10-year bPFS rates (RR = 1.12, 95% CI: 1.02–1.23, P = 0.001) compared with BT monotherapy. However, BT combined with HT did not increase the patients' 5-year OS rates (RR = 1.02, 95% CI: 0.99–1.095, P = 0.1) compared with BT monotherapy.

Conclusions: BT combined with HT can increase the bPFS rates of patients with localized prostate cancer, but it does not improve patients' OS rates.

Five-year effectiveness of low-dose-rate brachytherapy: comparisons with nomogram predictions in patients with non-metastatic prostate cancer presenting significant control of intra- and periprostatic disease

PURPOSE

To assess the effectiveness of low-dose-rate (LDR) brachytherapy in patients with localized prostate cancer and to compare the outcome with predictions from Kattan and Partin nomograms at 60 months after seed implantation.

MATERIAL AND METHODS

One thousand, one hundred and eighty-seven patients with localized prostate cancer at low-, intermediate-, or high-risk of progression received LDR brachytherapy using iodine-125 seeds with curative intent, applied as monotherapy or in combination with external beam radiation therapy (EBRT), and/or androgen deprivation therapy (ADT). At 60 months after seed implantation, data of 1,064 patients (1,058 alive + 6 who died of prostate cancer) were analyzed for biochemical progression-free survival (bPFS) based on prostate-specific antigen (PSA) levels using the Phoenix definition. Five-year bPFS probabilities were determined for various risk group classifications (d'Amico, Mt. Sinai, MSKCC/Seattle, NCCN). Outcomes were also compared to patient-individualized nomogram predictions of 5-year bPFS (Kattan 2002) and probability of organ-confined disease (Kattan 2002, Partin 2007).

RESULTS

Overall, 93.3% (993/1,064) of the patients were free of biochemical progression within 5 years, while the average 5-year bPFS probability according to the Kattan nomogram was significantly lower (85%, p < 0.001). Outcomes were significantly better than Kattan nomogram predictions in the subgroup of patients with monotherapy as well as in patients additionally treated with EBRT. Comparison of the overall outcome with nomogram predictions for organ-confined disease (Kattan nomogram: 50%; Partin nomogram: 65%) revealed a significant probability of LDR brachytherapy to destroy periprostatic tumor spread (p < 0.001) in all risk group constellations, even in high-risk patients.

CONCLUSIONS

The results indicate high effectiveness of LDR brachytherapy in all risk groups, significantly better than predicted with the Kattan nomogram in most subgroups. The significant superiority of LDR brachytherapy compared to nomogram predictions of organ-confined disease suggests that LDR brachytherapy effectively controls both intra- and periprostatic disease.