A phase 3 clinical trial reports that adding docetaxel to a standard regimen consisting of radiotherapy and long-term androgen suppression (AS) therapy improves outcomes for men with high-risk nonmetastatic prostate cancer.
In the United States, prostate cancer is the second leading cause of cancer-related death among men. Of the 20% of patients whose prostate cancer is considered high risk, around 30% to 40% experience a relapse following initial treatment. Less than 50% of these patients are cured.
Because docetaxel-based chemotherapy has improved overall survival both in men with castration-resistant prostate cancer and in men with castration-sensitive prostate cancer, the researchers behind the NRG Oncology trial NRG-RTOG 0521 hypothesized that adding it to standard treatment with radiotherapy and long-term AS therapy could improve disease control and survival in patients with high-risk disease without producing metastasis.
The study enrolled 612 patients with high-risk nonmetastatic prostate cancer. The 563 patients who were evaluable had a median prostate-specific antigen of 15.1 ng/mL; 53% had cancer scoring 9 to 10 on the Gleason scale, and 27% had cT3 to cT4 disease. Patients were followed for a median of 5.7 years.
Adding docetaxel-based chemotherapy to radiotherapy/AS improved the rate of four-year overall survival compared with radiotherapy/AS alone (93% vs 89%). In the docetaxel arm, there were both fewer deaths overall (43 vs 59) and fewer deaths resulting from prostate cancer (16 vs 23). In addition, adding docetaxel to radiotherapy/AS lowered the six-year rate of distant metastasis (9.1% vs 14%) and increased the six-year disease-free survival rate (65% vs 55%). Treatment was well tolerated by patients in both study arms.
"These are promising results," commented Seth A. Rosenthal, MD, FACR, FASTRO. Dr. Rosenthal, a radiation oncologist of Sutter Medical Group and Sutter Cancer Centers in Sacramento, California, is the lead author of the study, published in the Journal of Clinical Oncology. "The trial results suggest that the addition of docetaxel chemotherapy to standard treatment with long-term androgen suppression therapy and [radiotherapy] is a viable treatment option for men with high-risk nonmetastatic prostate cancer. Physicians should be considering the discussion of this option with selected patients who are fit for chemotherapy."
For More Information
Rosenthal SA, Hu C, Sartor O, et al (2019). Effect of chemotherapy with docetaxel with androgen suppression and radiotherapy for localized high-risk prostate cancer: the randomized phase III NRG oncology RTOG 0521 trial. J Clin Oncol. [Epub ahead of print] DOI:10.1200/JCO.18.02158
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