Study suggests chemotherapy after radical prostatectomy may benefit men who are at high risk for relapse

Not all men with prostate cancer benefit from adjuvant chemotherapy after radical prostatectomy; however, African American men and men with a higher tumor stage may, according to a new U.S. Department of Veterans Affairs (VA) study featured at the 111th Annual Scientific Meeting of the American Urological Association (AUA). The research will be highlighted by study authors during a special press conference. Sam S. Chang, MD, MBA, AUA spokesperson, Patricia and Rodes Hart Chair in Urologic Surgery and Professor of Urologic Surgery at Vanderbilt Medical Center will moderate the session at the San Diego Convention Center in San Diego, CA on May 7, 2016.

This year, approximately 200,000 men will be told they have prostate cancer. In the United States alone, it is the leading cause of cancer in Veterans and the second most common cancer in men, affecting one in seven. Odds increase to one in five if the men are African American and one in three if they have a family history. Each year, more than 130,000 men opt for a radical prostatectomy to treat this disease; however, because 20-30 percent of these men will be found to have locally advanced or high-grade disease, they will be at risk for relapse. As such, researchers from VA centers across the U.S. sought to examine the efficacy of early adjuvant chemotherapy on patients who had a radical prostatectomy, but who based on clinical and pathologic parameters, were high risk for relapse.

Publication Number: PI LBA 06

Nearly 300 patients at high risk for relapse after prostatectomy were randomized in a 1:1 ratio to either a standard of care observation group or to a chemotherapy group where docetaxel and prednisone were administered every 3 weeks for 18 weeks. Randomization was stratified for prostate-specific antigen (PSA), Gleason score, tumor stage and the presence of positive margins.

Patients were observed via PSA for a minimum of one, up to a maximum of five years. Results showed:

• Adjuvant chemotherapy in high-risk prostate cancer using docetaxel and prednisone was tolerated well by patients
• Of those who received chemotherapy, there was no statistically significant improvement in progression-free survival for the population as a whole; however, benefit in progression-free survival was seen in African American men (HR 0.54, 95 percent CI 0.29-1.01, p=0.054) and men with higher risk pathology ≥T3b (HR 0.58,95 percent CI 0.34-0.98, logrank test p=0.041)
• The most common adverse events ≥Grade 3 related or possibly chemotherapy related included neutropenia in 40 percent, hyperglycemia in 18 percent, and fatigue in 5 percent, with febrile neutropenia in 1.4 percent.

"What this study shows is that men with aggressive disease, thus at higher risk for prostate cancer relapse, may benefit the most from chemotherapy after radical prostatectomy," said Dr. Chang. As urologists, we are always looking for new treatment options for our patients following localized therapy. Despite our best efforts, our established treatments for localized prostate cancer fail 30 percent of the time. Knowing to whom we should offer adjuvant chemotherapy is a real step forward in our attempts to improve our therapy success."