Previous research has demonstrated a daily treatment for 2 months of conventionally fractionated high dose external beam radiation therapy (CRT), decreases prostate cancer recurrence and improves metastasis-free survival. Additional studies have demonstrated that moderate hypo-fractionated radiation therapy (HRT), consisting of daily treatment for 1 month using a larger dose per treatment, provides a similar low risk of recurrence and may even be lower with HRT than CRT.
In this study, the researchers wanted to test the latter hypothesis. To achieve this, the team led by investigators at Brigham and Women’s Hospital (MA, USA) analyzed data from over 5000 men from three randomized studies comparing HRT with CRT in men with prostate cancer. The findings were recently published in European Urology Focus.
Of the 5484 men, 64.8% had intermediate-risk prostate cancer. HRT as compared with CRT was associated with a significant 13% reduction in the risk of recurrence. No significant difference in overall survival was found between HRT and CRT but researchers noted that the possibility exists that men in excellent health could also achieve an overall survival benefit with HRT as compared with CRT.
Overall, the researchers demonstrated that 1-month duration HRT was associated with a significant improvement in recurrence compared to the 2-month duration CRT and therefore would be reasonable to consider in men with intermediate risk prostate cancer and who do not have risk factors that could predispose the patient to bladder side effects several years after the treatment is complete.
First author, Trevor Royce from Brigham and Women’s Hospital commented on the findings: “Our results provide evidence for clinicians to consider HRT as compared with CRT as a preferred radiation treatment in men with intermediate-risk prostate cancer and at low risk of other complications. Treatment with a shorter course of radiation and higher doses over fewer days may be the preferred approach in appropriately selected patients with localized prostate cancer, reducing treatment time and cost to the patient, and increasing patient convenience and access to treatment.”
“Late bladder and urethra toxicities were noted to be higher in the HRT as compared to CRT group which necessitates carefully choosing men who are not at risk for sustaining a late bladder or urethral side effect,” explained senior author of the study, Anthony D’Amico (Brigham and Women’s Hospital). “Men to exclude would be those who get up more than three times at night to urinate, or have urgency to urinate, or incontinence, or men who are on anti-coagulants that could increase the risk of bleeding.”
The researchers stated that additional studies are required, utilizing individual patient-level data among men with high risk prostate cancer to assess the benefit of HRT and whether treatment toxicity, particularly those to the bladder and urinary system are also low with HRT.