Multimodality therapy critical for treating more aggressive prostate cancers

Findings

Men with high-risk prostate cancer with at least one additional aggressive feature have the best outcomes when treated with multiple healthcare disciplines, known as multimodality care, according to a UCLA study led by Dr. Amar Kishan, assistant professor of radiation oncology at the David Geffen School of Medicine at UCLA and a researcher at the UCLA Jonsson Comprehensive Cancer Center.

The study found no difference in prostate cancer-specific deaths across treatment modalities when patients received guideline-concordant multimodality therapy, which in this case was inclusion of hormone therapy for men receiving radiation and a low-bar for postoperative radiation in men undergoing surgery. The research team did however, find significant differences in deaths when guideline-concordant multimodality care was not delivered. Those treated with external beam radiotherapy or external beam radiotherapy with a brachytherapy boost were consistently associated with lower rates of distant metastasis (8% with EBRT+BT, 16% with EBRT, and 24% with RP, at 10 years).

Background

The optimal treatment for patients with high-risk prostate cancer and additional aggressive features is currently unknown. It is important to understand whether multimodality care can help improve outcomes for this patient population without increasing side effects and lowering the quality of life. The researchers sought to find whether there was a difference in prostate cancer-specific mortality and distant metastasis associated with radiotherapy or radical prostatectomy.

Method

UCLA investigators collaborated with 15 other institutions around the world to investigate treatment outcomes in 6,004 men with high-risk prostate cancer and at least one adverse clinicopathologic feature, which can include a Gleason grade group 4-5 diagnosis, disease extending into the seminal vesicles or tumor extending outside of the prostate capsule. Of the group, 3,175 underwent radiotherapy or upfront radical prostatectomy, 1,830 underwent external beam radiotherapy and 999 underwent external beam radiotherapy with a brachytherapy boost.

Impact

The study shows multimodality therapy is critical for treating more aggressive prostate cancers. While multimodality therapy resulted in equal drops in cancer-specific death, there were still lower rates of metastases in men receiving primary radiation, particularly with extremely high dose radiation, in conjunction with hormone therapy. This suggests men with very aggressive prostate cancers might have undetected disease outside the prostate. A type of systemic therapy that has an impact all throughout the bloodstream, such as hormonal therapy, might be helpful even in men receiving surgery.