Optimizing Treatment in Intermediate-Risk Prostate Cancer: Secondary Analysis of a Randomized Phase 3 Trial

Short-term Darolutamide (ODM-201) Concomitant to Radiation Therapy for Patients with Unfavorable Intermediate-risk Prostate Cancer: The Darius (AFU-GETUG P15) Phase 2 Trial Protocol

BACKGROUND

Combination of androgen deprivation therapy (ADT) with external beam radiation therapy (EBRT) is a standard of care for patients with intermediate-risk prostate cancer (PCa). However, 6 months of ADT generates multiple side effects impacting quality of life (QoL). Darolutamide (an androgen receptor targeting agent [ARTA]) is associated with low blood-brain barrier penetrance and less drug-drug interaction.

OBJECTIVE

To assess the efficacy of a combination of 6 months of darolutamide with EBRT to treat patients with unfavorable intermediate-risk PCa.

DESIGN, SETTING, AND PARTICIPANTS

The DARIUS trial is a multicenter randomized non comparative phase 2 trial, randomizing the 6-months darolutamide + EBRT arm versus 6-months ADT + EBRT in patients with unfavorable intermediate-risk PCa.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The primary endpoint is a biological response defined as prostate-specific antigen ≤0.1 ng/ml at month six of darolutamide or ADT. The key secondary endpoints are biochemical recurrence-free survival, disease-free survival, safety, and QoL. Ancillary studies using radiomics and genomic classifier are planned. Sixty-two patients will be included.

RESULTS AND LIMITATIONS

In this population of patients requiring ADT combined with EBRT, the use of an ARTA alone, such as darolutamide, may demonstrate antitumoral efficacy while minimizing toxicity and maintaining QoL. Limitations are mainly inherent to the open-label design of this study.

CONCLUSIONS

Six months of darolutamide + EBRT compared with 6 months of ADT + EBRT may be efficient in terms of a biological response, avoiding toxicity and altered QoL attributable to ADT in patients with unfavorable intermediate-risk PCa.

PATIENT SUMMARY

The ongoing DARIUS clinical trial assesses short-term (6 months) darolutamide treatment in association with external beam radiation therapy in men with localized prostate cancer. The trial investigates whether single-agent darolutamide can improve the biological response while maintaining a favorable tolerability profile.

Prostate-specific antigen kinetics in hypofractionated radiation therapy alone for intermediate- and high-risk localized prostate cancer

Background

This study aimed to evaluate the treatment outcomes and define the prostate-specific antigen (PSA) kinetics as potential prognostic factors in patients with intermediate- or high-risk localized prostate cancer (PCa) who underwent moderately hypofractionated radiation therapy.

Methods

The study retrospectively reviewed the medical records of 149 patients with intermediate- or high-risk localized PCa who underwent definitive radiation therapy (70 Gy in 28 fractions) without androgen deprivation therapy. Clinical outcomes were analyzed based on risk stratification (favorable-intermediate, unfavorable-intermediate, and high-risk). The biochemical failure rate (BFR) and clinical failure rate (CFR) were stratified based on the PSA nadir and the time to the PSA nadir to identify the prognostic effect of PSA kinetics. Acute and late genitourinary and gastrointestinal adverse events were analyzed.

Results

Significant differences were observed in the BFR and CFR according to risk stratification. No recurrence was observed in the favorable intermediate-risk group. The 7-year BFR and CFR for the unfavorable intermediate-risk and high-risk groups were 19.2% and 9.8%, and 31.1% and 25.3%, respectively. Patients with a PSA nadir >0.33 ng/mL or a time to the PSA nadir <36 months had a significantly greater BFR and CFR. The crude rate of grade 3 late adverse events was 3.4% (genitourinary: 0.7%; gastrointestinal: 2.7%). No grade 4-5 adverse event was reported.

Conclusion

A significant difference in clinical outcomes was observed according to risk stratification. The PSA nadir and time to the PSA nadir were strongly associated with the BFR and CFR. Therefore, PSA kinetics during follow-up are important for predicting prognosis.

The Swedish national guidelines on prostate cancer, part 1: early detection, diagnostics, staging, patient support and primary management of non-metastatic disease

OBJECTIVE

There is now an unprecedented amount of evidence to consider when revising prostate cancer guidelines. We believe that there is a value in publishing summaries of national clinical guidelines in English for others to read and comment on.

METHODS

This is part 1 of a summary of the Swedish prostate cancer guidelines that were published in June 2022. It covers the early detection, diagnostics, staging, patient support and management of the non-metastatic disease. Part 2 covers recurrence after local treatment and management of the metastatic disease.

RESULTS

The 2022 Swedish guidelines include several new recommendations: rectal iodine-povidone to reduce post-biopsy infections, external beam radiation with focal boost to the tumour, use of a pre-rectal spacer to reduce rectal side effects after external beam radiotherapy in some expert centres, 6 months' concomitant and adjuvant rather than neoadjuvant and concomitant hormonal treatment together with radiotherapy for unfavourable intermediate and high-risk disease, and adjuvant abiraterone plus prednisolone together with a GnRH agonist for a subgroup of men with very high-risk disease. The Swedish guidelines differ from the European by having more restrictive recommendations regarding genetic testing and pelvic lymph node dissection, the risk group classification, recommending ultra-hypofractionated (7 fractions) external radiotherapy for intermediate and selected high-risk cancers, by not recommending any hormonal treatment together with radiotherapy for favourable intermediate-risk disease, and by recommending bicalutamide monotherapy instead of a GnRH agonist for some patient groups.

CONCLUSIONS

The 2022 Swedish prostate cancer guidelines include several new recommendations and some that differ from the European guidelines.

Patients’ Preferences for Androgen Deprivation Therapy in the Treatment of Intermediate-Risk Prostate Cancer

Background. For men with intermediate-risk prostate cancer (IRPC), adding short-term androgen deprivation therapy (ADT) to external beam radiation therapy (EBRT) has shown efficacy, but men are often reluctant to accept it because of its impact on quality of life. Methods. We conducted time tradeoffs (score of 1 = perfect health and 0 = death) and probability tradeoffs with patients aged 51 to 78 y who had received EBRT for IRPC within the past 2 y. Of 40 patients, 20 had received 6 mo of ADT and 20 had declined. Utility assessments explored 4 ADT-related side effects: hot flashes, fatigue, loss of libido/erectile dysfunction, and weight gain. Results. The most commonly reported “worst” treatment-related complication of ADT was fatigue (50% in both cohorts) followed by reduced libido/erectile dysfunction (40% in both cohorts). The utilities for fatigue were mean = 0.71 and median = 0.92 and for reduced libido/erectile dysfunction were mean = 0.81 and median = 0.92. Utilities did not differ significantly between cohorts. Assuming a 6-mo course of ADT, men reported being willing to trade 3 mo of life expectancy to avoid fatigue due to ADT and 1.8 mo to avoid sexual side effects. Patients in the ADT cohort were willing to accept the side effects of ADT in exchange for a mean 8% absolute increase in survival, whereas patients in the no ADT cohort required a 16% increase ( P < 0.001). Conclusions. When considering treatment with ADT, men with IRPC identified fatigue and sexual dysfunction as the most bothersome side effects. Patients who declined ADT expected a larger survival benefit than those who opted for treatment. Both groups expected a survival benefit exceeding that shown by recent trials, suggesting some men may be selecting treatments inconsistent with their preferences.

Highlights

This study demonstrates that prostate cancer patients receiving radiation therapy are reluctant to receive androgen deprivation therapy (ADT) most commonly due to anticipated fatigue and loss of libido/erectile dysfunction. Men who had received ADT reported they would require an average 8% absolute increase in survival to tolerate its side effects, whereas those who declined ADT would require an average 16% increase. Required thresholds are well above the estimated absolute survival benefit for ADT demonstrated in recent clinical trials, suggesting an unmet need for improved patient education regarding the risks and benefits of ADT.

Short-term ADT and Dose-escalated IMRT in Patients With Intermediate-risk Prostate Cancer: Benefit or Caution?

OBJECTIVES

In the era of dose-escalated prostate radiation therapy (RT), the use of androgen deprivation therapy (ADT) is undefined for intermediate-risk (IR) prostate cancer. There is growing concern of the risk of ADT to be detrimental to quality of life. This single-institution retrospective analysis aimed to evaluate outcomes of IR patients treated with dose-escalated intensity modulated radiation therapy (IMRT) with or without concurrent/adjuvant short-term ADT.

MATERIALS AND METHODS

Data was collected from 260 consecutive patients treated with dose-escalated IMRT with daily image-guided RT for newly diagnosed IR prostate cancer. Biochemical recurrence-free survival (BCRFS), distant metastasis-free survival, prostate cancer-specific survival, and overall survival (OS) were calculated using Kaplan-Meier methodology.

RESULTS

Median follow-up was 93 months. A total of 181 patients had unfavorable IR disease, and 36.2% (N=94) received ADT, with median ADT duration of 6 months. Seven-year BCRFS was 94.1% vs. 86.2% (P=0.067), for ADT and no ADT, respectively, and no difference in distant metastasis-free survival or prostate cancer-specific survival was observed. ADT was associated with significantly worse 7-year OS (80.0% vs. 91.3%, P=0.010). Analysis of the unfavorable IR cohort alone, showed similar results; 7-year BCRFS and 7-year OS in patients who received ADT versus no ADT were 93.7% vs. 85.9% (P=0.093), and 79.0% vs. 90.6% (P=0.019), respectively.

CONCLUSIONS

In our 15-year experience treating IR prostate cancer with dose-escalated IMRT with daily image-guided RT, short-term concurrent ADT was associated with a statistically significant worse OS. Additional studies are needed to determine if ADT is beneficial or detrimental for patients with IR prostate cancer treated with dose-escalated radiation.

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.