The ORIOLE trial phase 2 trial was conducted across 3 US institutions. The trial included 54 patients with recurrent hormone-sensitive prostate cancer and 1 to 3 metastases detectable by conventional imaging who had not received ADT within 6months of enrollment or 3 or more years total. The patients were randomized to observation vs. SABR for the metastatic sites. The results showed that 7 out of 36 patients (19%) receiving SABR and 11 of 18 patients (61%) undergoing observation experienced disease progression at 6 months (p=0.005). Treatment with SABR improved median progression-free survival (not received vs. 5.8 mon; HR 0.30; 95% CI0.11-0.81, p=0.002). In conclusion, treatment with SABR for oligometastatic prostate cancer improved outcomes.

(Open Access)

Reference (PubMed Link): Phillips R, Shi WY, Deek M, et al. Outcomes of observation vs stereotactic ablative radiation for oligometastatic prostate cancer: The oriole phase 2 randomized clinical trial. JAMA Oncol 2020;6:650-9.

Key Institution: Multi-Institutional (US)
Keywords: Oligometastatic prostate cancer, SABR

The HYPRO trial I a phase 3 study evaluating the effects of hypofractionated (HF) RT compared to conventionally fractionated (CF) RT in the treatment of intermediate and high risk prostate cancer.  Patients were randomly assigned to 64.6 Gy in 19 (BED 90.4) fractions or 78 Gy in 29 fractions (BED 78).  The primary endpoint was relapse-free survival at 7 years.  A total of 820 patients were enrolled on the trial.  ADT was given to a total of 67% of patients on the study.  At 7 years, there was no significant difference in relapse-free survival on the two arms (71.7% on the HF arm vs 67.6% on the CF arm).  Additionally, there were no differences in OS or treatment failure on the two arms.

These updated results confirmed the author’s previously reported findings that hypofractionation (with dose escalation based on EQD2) did not translate to improved treatment outcomes compared to conventionally fractionated RT.

Reference (PubMed Link): de Vries KC, Wortel RC, Oomen-de Hoop E, et al. Hyprofractionated versus conventionally fractionated radiation therapy for patients with intermediate- or high-risk, localized, prostate cancer: 7-year outcomes from the randomized, multicenter, open-label, phase 3 hypro trial. Int J Radiat Oncol Biol Phys 2020;106:108-115.

Key Institution: Multi-Institutional (Europe)
Keywords: Hypofractionated, Prostate cancer, EBRT, high risk, intermediate risk 

External beam radiation is a common treatment for localized prostate cancer, traditionally given over 7-8 weeks of treatment with fraction sizes of 2Gy or smaller. Several recent trials have demonstrated that moderately hypofractionated treatments given over ~4 weeks in fraction sizes larger than 2Gy, have equivalent 5-year disease control rates. Clinician assessed toxicity suggests a possible increase in late genitourinary (GU) toxicity with hypofractionation, however there is little data on patient reported outcomes. 

The present study looked at patient reported outcomes from a cohort of 17,058 men in England who underwent prostate RT with curative intent between April 2014 and September 2016. All patients were mailed a survey that included the EPIC-26 questionnaire (addressing urinary, bowel and sexual function) and the EuroQol EQ-5D-5L questionnaire (quality of life).  There was a 77% response rate resulting in 13,131 completed surveys. 64% of patients received conventional RT and 36% received hypofractionated. Hypofractionation was associated with statistically better sexual and hormonal function scores, however these were small differences that did not meet prespecified thresholds for clinically significant change. There was no difference between the treatments in urinary function, bowel function, or overall quality of life. 

Strengths of the study include the large size and high response rate. The study reflects a real-world population of patients treated in the British NHS as opposed to a carefully selected clinical trial population. Limitations include the fact that some late toxicity may only manifest with a longer follow up period. Also, as the surveys were conducted after treatment, patient reported information was not available on baseline GI and GU function. Overall, the study suggests there is no significant difference in patient reported outcomes between conventional and hypofractionated RT for prostate cancer and adds to the growing evidence base for the use of hypofractionated treatment.

Reference (PubMed Link): Nossiter J, Sujenthiran A, Cowling TE, et al. Patient-reported functional outcomes after hypofractionated or conventionally fractionated radiation for prostate cancer: A national cohort study in england. J Clin Oncol 2020;38:744-752.

Key Institution: United Kingdom 
Keywords: Prostate cancer, hypofractionation, quality of life, patient reported outcomes

This is a randomized trial comparing adjuvant radiotherapy versus observation for men with prostate adenocarcinoma pT2a with positive margins or pT3a. All patients were N0M0, had a preoperative PSA of ≤20 ug/l and post-operative PSA <0.5 ug/l. Of 250 patients in the study, 126 received adjuvant radiotherapy to 66.6 Gy. 

The primary endpoint of this study was biochemical recurrence free survival, and secondary endpoints included overall survival, cancer-specific survival, local recurrence, and adverse events. 

At median follow up of 9.3 years in the adjuvant group the 10 year freedom from biochemical recurrence was 82% with adjuvant therapy versus 61% in the observation group (HR 0.26 0.14-0.48, p<0.001). The difference in OS of 92% versus 87% in the adjuvant and observation groups, respectively, was not statistically significant. There was also no statistically significant difference in metastatic free survival or prostate cancer specific survival.  

This trial is unique from historical trials given that patients with pT2 with positive margins were included, most adjuvant trials have limited to pT3-4. Evaluating the pT2 patients as a single group, 3/73 patients that received adjuvant RT experienced biochemical progression, compared with 21/63 in the observation group. Of the 43 patients in observation group with biochemical progression, 37 went on to receive salvage RT median 20 weeks from progression, and 28 of those patients achieved PSA remission.  

When this study was designed a PSA of <0.5 ug/l was defined as undetectable, whereas in today’s era <0.2 ug/l is most commonly accepted.  

In conclusion, this study demonstrates improved freedom from biochemical progression with adjuvant radiotherapy versus observation for pT2 with positive margins or pT3 patients. There is a slightly higher risk of grade 3 toxicity, most commonly seen as erectile dysfunction and urinary incontinence, so there should be informed discussion between the physician and patient when deciding if adjuvant therapy should be delivered.  

(Open Access)

Reference (PubMed Link): Hackman G, Taari K, Tammela TL, et al. Randomised trial of adjuvant radiotherapy following radical prostatectomy versus radical prostatectomy alone in prostate cancer patients with positive margins or extracapsular extension. Eur Urol 2019;76:58+F106-595.

Key Institution: Multi-institutional/Finland
Keywords: Prostate cancer, adjuvant radiotherapy, positive margins 

Updated report of ProtecT trial which reported intention-to-treat analysis of UK men with localized prostate cancer randomized to active monitoring (AM), radical prostatectomy (RP), or radiation (RT). 1643 men included. More men in AM group died of PCa (AM=1.85%, RP=0.67%, RT=0.73%), p= 0.003 when comparing AM vs treatment arms. Metastases (AM 5.6%, RP 2.4%, RT 2.7%) and disease progression (AM 20.35%, RP 5.87%, RT 6.62%) were both more common in AM arm. There were higher risks of sexual dysfunction (95% at 6 mo) and urinary incontinence (55% at 6 mo) after RP, and of sexual dysfunction (88% at 6 mo) and bowel dysfunction (5% at 6 mo) after RT. Overall, more than 95% of patients with low or intermediate risk localized prostate cancer do not die of prostate cancer within 10 year, irrespective of treatment or active monitoring, though risk of disease progression is higher with AM.  

(Open Access)

Reference (PubMed Link): Neal DE, Metcalfe C, Donovan JL, et al. Ten-year mortality, disease progression, and treatment-related side effects in men with localised prostate cancer from the protect randomised controlled trial according to treatment received. Eur Urol 2019.

Key Institution: Multi-Institutional (UK)
Keywords: Prostate cancer, active monitoring, prostatectomy, radiation therapy