CCTG PR13 RADICALS: Long-Term ADT with Radiation Helps Prevent Post-Prostatectomy Metastases

No benefit seen with short-term hormone therapy versus radiotherapy alone
Long-Term ADT with Radiation Helps Prevent Post-Prostatectomy Metastases

First results from the CCTG PR13 RADICALS: Radiotherapy and Androgen Deprivation In Combination After Local Surgery were presented at the European Society for Medical Oncology (ESMO) 2022 annual congress in Paris France on September 12.

In men undergoing radiotherapy after radical prostatectomy, 2 years of androgen deprivation therapy (ADT) improved outcomes compared with a shorter course of ADT. At a median follow-up (9 years) investigators found that the longer ADT improved metastasis-free survival (MFS) compared with a 6-month course.

"However, short-course hormone therapy compared with no hormone therapy did not meaningfully improve metastasis-free survival," reported Chris Parker, MD, of the Institute of Cancer in London, who presented the findings during the Presidential Symposium session.

Radiation therapy uses high-energy x-rays to kill tumor cells. Androgens can cause the growth of prostate cancer cells. Androgen deprivation therapy, such as goserelin, leuprolide, or bicalutamide, may lessen the amount of androgens made by the body. Giving radiation therapy together with androgen deprivation therapy may kill more prostate cancer cells.

"The results showed an advantage of 24 months compared to 6 months in those patients deemed appropriate candidates for hormone therapy. Conversely, there was no advantage seen with 6 months of therapy compared to no hormone therapy in those patients randomized to this comparison, suggesting that post operative radiotherapy may be sufficient treatment in men for whom hormone therapy is deemed to have questionable benefit," says Dr Wendy Parulekar, CCTG Senior Investigator.

This trial represents a meaningful collaboration between CCTG and international academic groups. The findings provide additional data to guide patients and clinicians in their shared decisions regarding duration of hormone therapy in combination with radiotherapy after prostatectomy.