The study confirmed a disease-specific-survival (DSS) rate of 95 percent when patients received fewer weeks of neoadjuvant (NEO) total androgen suppression (TAS).
The multi-institutional phase III trial, Radiation Therapy Oncology Group (RTOG) 9910, evaluated 1,490 intermediate-risk prostate cancer (PCa) patients from 152 institutions in the U.S. and Canada. Patients were accrued from 2000 to 2004 and followed for an average of 9 years, and the average age of the men was 71 at the time of accrual. The patients were stratified and randomized into two groups—Group 1 consisted of 752 patients who received eight weeks of NEO TAS, and Group 2 consisted of 738 patients who received 28 weeks of NEO TAS. Both groups then received eight weeks of external beam radiation therapy (RT) and concurrent TAS.
Cumulative incidence was used to estimate and test efficacy for DSS, prostate-specific antigen (PSA) failure, locoregional tumor progression and distant metastasis. Overall survival (OS) rates were estimated via the Kaplan-Meier method and efficacy tested with log rank. There were 30 PCa deaths in Group 1, for a 10-year DSS rate of 95 percent; and 24 PCa deaths in Group 2, for a 10-year DSS rate of 96 percent (no statistical difference). There were 200 additional deaths not attributable to PCa in Group 1 for a 10-year OS rate of 66 percent, and 196 such deaths in Group 2, for a 10-year OS rate of 67 percent. By 10 years, 27 percent of patients had a PSA failure (using the newer RTOG-ASTRO definition of nadir+2), 5 percent had PCa recurrence in the prostate (locoregional) and 6 percent had distant metastasis. Hot flashes and erectile dysfunction were more common in Group 2.
“Sometimes, preliminary research leads us to assume that more treatment is better, but this study serves as a strong cautionary note to put the promising treatment to the test,” said Thomas Pisansky, MD, lead author of the study and professor of radiation oncology at the Mayo Clinic in Rochester, Minn. “Overall, both groups had very, very good outcomes, but patients assigned to Group 2 had more side effects from androgen suppression than Group 1, who received only eight weeks of NEO TAS. Now, investigators know the upper boundary of how much androgen suppression is needed in this group of patients. The results have substantial importance because they can alter the research strategy to one in which investigation can now concentrate on ways to simplify the treatment and further reduce side effects.”
The abstract, “Radiation Therapy Oncology Group 9910: Phase III Trial to Evaluate the Duration of Neoadjuvant (NEO) Total Androgen Suppression (TAS) and Radiation Therapy (RT) in Intermediate-Risk Prostate Cancer (PCa),” will be presented in detail during the Plenary session at ASTRO’s 55th Annual Meeting at 2:00 p.m. Eastern time on September 23, 2013. To speak with Dr. Pisansky, contact Michelle Kirkwood on September 22-25, 2013, in the ASTRO Press Office at the Georgia World Congress Center in Atlanta at 404-222-5303 or 404-222-5304, or email Michelle Kirkwood.
ASTRO’s 55th Annual Meeting, held in Atlanta, September 22-25, 2013, is the premier scientific meeting in radiation oncology and brings together more than 11,000 attendees including oncologists from all disciplines, medical physicists, dosimetrists, radiation therapists, radiation oncology nurses and nurse practitioners, biologists, physician assistants, practice administrators, industry representatives and other health care professionals from around the world. The theme of the 2013 meeting is “Patients: Hope • Guide • Heal” and will focus on patient-centered care and the importance of the physician’s role in improving patient-reported outcomes and the quality and safety of patient care. The four-day scientific meeting includes presentation of four plenary papers, 363 oral presentations, 1,460 posters and 144 digital posters in 70 educational sessions and scientific panels for 19 disease sites/tracks. Keynote and featured speakers include: William B. Munier, director of the Center for Quality Improvement and Patient Safety at the Agency for Healthcare Research and Quality; Darrell G. Kirch, MD, president and CEO of the Association of American Medical Colleges; James Cosgrove, PhD, director of the U.S. Government Accountability Office; Otis W. Brawley, MD, chief medical officer of the American Cancer Society; and Peter Friedl, MD, PhD, of St. Radboud University Nijmegen Medical Centre at the University of Nijmegen and MD Anderson Cancer Center.
ASTRO is the premier radiation oncology society in the world, with more than 10,000 members who are physicians, nurses, biologist, physicists, radiation therapists, dosimetrists and other health care professionals that specialize in treating patients with radiation therapies. As the leading organization in radiation oncology, the Society is dedicated to improving patient care through professional education and training, support for clinical practice and health policy standards, advancement of science and research, and advocacy. ASTRO publishes two medical journals, International Journal of Radiation Oncology•Biology•Physics (www.redjournal.org) and Practical Radiation Oncology (www.practicalradonc.org); developed and maintains an extensive patient website, www.rtanswers.org; and created the Radiation Oncology Institute (www.roinstitute.org), a non-profit foundation to support research and education efforts around the world that enhance and confirm the critical role of radiation therapy in improving cancer treatment. To learn more about ASTRO, visit www.astro.org.
- Michelle Kirkwood