CHICAGO—Neoadjuvant chemoradiation prior to radical prostatectomy can achieve local disease control in patients with high-risk localized prostate cancer (PCa), a study found.
Of 25 such patients in a study who received the treatment prior to surgery, only one had detectable PSA post-operatively, said lead investigator Mark Garzotto, MD, Associate Professor of Urology and Radiology at Oregon Health & Science University in Portland. “The one patient with detectable PSA levels had bulky lymph nodes,” he said. “It was because the tumor had already left the barn.”
Post-operatively, usually 10% of patients with high-risk localized PCa have a detectable PSA, said Dr. Garzotto, who presented study findings at the 47th Annual Meeting of the American Society of Clinical Oncology.
High-risk localized PCa remains a considerable therapeutic challenge in part because of an inability to attain local control with either surgery or radiation monotherapy. Neoadjuvant chemoradiation improves local relapse rates of several tumor types but until now has not been evaluated in patients with PCa.
Dr. Garzotto and his team conducted a Phase1/2 study to assess the safety and pathologic complete response rate of pre-operative docetaxel and intensity-modulated radiotherapy (IMRT). Secondary endpoints in the study were biochemical recurrence-free survival and PSA response to combined treatment. The cohort included men who had T2b or resectable T3a disease, PSA levels of 15 ng/mL or greater, or primary Gleason grade of 4 or higher. The median age of the men was 63.9 years (range 48-76 years) All the patients received 45 Gy over 25 fractions to the prostate and seminal vesicles.
Post-operatively, surgical margins were negative in 88% of cases and initial post-op PSA levels were undetectable in 24 patients. The men had a mean follow-up time of 29 months. The two- and three-year disease free rate was 84% and 66%, respectively. “Those are very good numbers,” Dr. Garzotto told Renal & Urology News. “Neoadjuvant [therapy] is commonly used for many cancers, such as colon cancer and male bladder cancer. We wanted to build on that concept. We took the most active agent that has synergy with radiation.” The regimen was well tolerated and patients experienced no unexpected toxicities.