WASHINGTON, DC USA (UroToday.com) - Dr. Ian Thompson argued for adjuvant radiotherapy (XRT) for prostate cancer after surgery.
Adjuvant XRT has been shown to have anti-cancer benefits across all domains for patients at risk. SWOG 8794 showed that pT3 disease had a decrease in PSA progression at 5 years from 77% to 62%, and metastatic disease from 39% to 29% in the adjuvant XRT arm. The metastasis-free survival was better by 2 years was was the overall survival. While one criticism is that XRT induces toxicity, it does decrease the need for androgen deprivation therapy. To avoid one death, the use of adjuvant XRT means the number of patients needed to treat is 9. One disadvantage of salvage is that patients will often have a PSA in the 4 range by the time they are referred for treatment. He offers it to all patients, but doesn’t believe that it is best for every patient.
Dr. Andrew Stephenson argued for salvage radiotherapy after radical prostatectomy. He asked whether XRT should be given to all patients or salvage XRT to some patients. There is no level-one evidence comparing adjuvant and salvage XRT. In the SWOG tria,l the reduction in deaths was largely due to fewer deaths from competing causes. In a salvage XRT trial, the pre-XRT PSA was 0.7ng/ml and there was a benefit in survival. Furthermore, in the SWOG and EORTC trials, one-third of patients had a PSA>0.2ng/ml at the time of XRT, so in fact they were given salvage treatment. At low PSA levels there is still a 50% cure rate with salvage XRT in their series. Salvage XRT would reduce the number of patients who are at long-term risk for secondary malignancy. He believed in early salvage, meaning when the PSA is <0.03ng/ml.
Dr. Sean Elliott presented a hypothetical model comparing adjuvant and salvage XRT for outcomes using all available data. Presumptions were that 75% of salvage patients would be treated at a PSA of 0.5ng/ml. The post-RT recurrence-free survival was similar at 10 years in this model. The crux is the maximum number of patients captured for salvage XRT.
Adjuvant: Ian Thompson, MD. University of Texas Health Science Center
Salvage: Andrew Stephenson, MD. Cleveland Clinic Foundation
Moderated by Sean Elliott, MD at the Society for Basic Urologic Research (SBUR)/Society of Urologic Oncology (SUO) joint meeting during the American Urological Association (AUA) Annual Meeting - May 14 - 19, 2011 - Walter E. Washington Convention Center, Washington, DC USA
Reported for UroToday by Christopher P. Evans, MD, FACS, Professor and Chairman, Department of Urology, University of California, Davis, School of Medicine.