Pelvic Radiotherapy Boosts Progression-Free Survival in Prostate Cancer Patients
Patients treated with hormone therapy before and during whole-pelvic radiotherapy for prostate cancer are more likely to have a progression-free survival than patients receiving radiation only to the prostate or those receiving hormone therapy after radiotherapy, according to a new study presented November 5, 2001, at the American Society for Therapeutic Radiology and Oncology's Annual Meeting in San Francisco.
Between April 1, 1995, and June 1, 1999, 1323 patients participated in the study titled "A Phase III Trial Comparing Whole-Pelvic to Prostate-Only Radiotherapy and Neoadjuvant Total Androgen Suppression: Preliminary Analysis of RTOG 9413." The median age for all patients was 70 years and nearly 25 percent were African-American. The median prostate specific antigen (PSA) for the patients was 22.8 ng/ml and 72 percent had a Gleason Score of 7-10.
The median follow-up for all patients since entering the study was 59.3. Patients treated with whole-pelvic radiotherapy experienced a 4-year progression-free survival of 56 percent compared to 46 percent when treated with prostate-only radiotherapy. Meanwhile, patients in the study who were treated with neoadjuvant hormone therapy experienced a 4-year progression free rate of 53 percent versus 48 percent for patients who underwent adjuvant hormone therapy.
When comparing all four arms in the study, there was a progression free survival advantage for patients who underwent neoadjuvant hormone therapy and whole-pelvic radiotherapy compared to patients who underwent neoadjuvant hormone therapy and prostate-only radiotherapy, adjuvant hormone therapy and whole-pelvic radiotherapy, and adjuvant hormone therapy and prostate-only radiotherapy (61 percent versus 45 percent, 49 percent and 47 percent respectively).
"This preliminary analysis demonstrates that whole-pelvic radiotherapy is associated with an improvement in progression free survival compared to prostate-only radiation therapy in patients with a risk of lymph node involvement greater than 15 percent," said Mack Roach, III, M.D., a member of the department of radiation oncology at the University of California San Francisco and lead author of the study. "The failure to see an early advantage in progression free survival with neoadjuvant hormone therapy compared to adjuvant hormone therapy may result from the fact that the time from the date of randomization to discontinuation of total androgen suppression is two months later on the adjuvant hormone therapy arms. Further analysis suggests that whole-pelvic radiotherapy plus neoadjuvant hormone therapy may be the best in terms of progression free survival and overall survival.
"This study proves that there is a real and meaningful biologic interaction between hormonal therapy and radiation and should change the way that many researchers view prostate cancer," Dr. Roach added.
If you would like a copy of the abstract or to speak to the lead author of the study, Mack Roach, III, M.D., please call Katherine Egan Bennett at the ASTRO Press Room at the Moscone Convention Center at (415) 978-3717 or e-mail her at [email protected]. Alternatively, you can call Lesley Nevers at ASTRO's headquarters at (703) 227-0141 or e-mail her at [email protected] for more information.
ASTRO is the largest radiation oncology society in the world, with more than 6,700 members who specialize in treating patients with radiation therapies. As a leading organization in radiation oncology, biology and physics, the society's goals are to advance the scientific base of radiation therapy and to extend the benefits of radiation therapy to those with cancer and other diseases.
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