Two abstracts presented during the Genitourinary (Prostate) Cancer Oral Abstract Session on Sunday, May 31, showed significantly improved overall survival (OS) when docetaxel chemotherapy was added to standard hormone therapy in patients with advanced, hormone-naive prostate cancer (Abstract 5001) and hormone therapy plus radiation therapy in men with high-risk localized prostate cancer (Abstract LBA5002)
Nicholas D. James, MD, PhD, of the University of Warwick and Queen Elizabeth Hospital Birmingham, United Kingdom, presented the first OS results from the randomized, controlled STAMPEDE trial, a multistage, multi-arm assessment of therapies for men with advanced, hormone-naive prostate cancer.
The trial was designed to continuously adapt the standard of care (SOC) aspect of the trial as new treatment options emerge. Dr. James presented results of four of the trial’s arms, which randomly assigned 2,962 men at a 2:1:1:1 ratio to SOC alone (at least 3 years of androgen-deprivation therapy with radiation when needed), SOC plus six cycles of docetaxel, SOC with zoledronic acid for 2 years, or SOC with docetaxel and zoledronic acid.
Sixty-one percent of the men had metastatic disease, and the rest had locally advanced, non-metastatic prostate cancer. Patients were followed for a median of 42 months.
There were 165 deaths in the SOC plus docetaxel arm compared with 405 in the SOC alone arm. Men assigned to docetaxel had a significantly improved median OS of 77 months compared with 67 months for men in the SOC arm
Howard M. Sandler, MD, of Cedars-Sinai Medical Center, presented the results of the phase III RTOG 0521 trial, a federally funded trial that compared outcomes in 562 men with high-risk, localized prostate cancer treated with androgen suppression and radiation therapy with or without the addition of adjuvant chemotherapy with docetaxel and prednisone.
The men were randomly assigned to standard therapy alone, defined as radiation therapy plus 2 years of androgen suppression, or standard therapy followed by six 21-day cycles of docetaxel/prednisone starting 4 weeks after radiation.
After a median of 6 years follow-up, there were 36 deaths in the chemotherapy arm compared with 52 in the standard therapy arm. The 4-year OS was 93% for the docetaxel/prednisone arm compared with 89% in the standard therapy arm.
Patients assigned to the docetaxel/prednisone arm had an improved 5-year disease-free survival rate of 73% compared with 66% for patients assigned standard therapy alone. The addition of docetaxel/prednisone resulted in a reduction in deaths from prostate cancer (23 vs. 16) and deaths due to other or unknown causes (36 vs. 27).