Ruth Etzioni, PhD
One-third of men over 70 years of age who undergo radical prostatectomy for prostate cancer and then experience biochemical recurrence have no need for salvage treatment, according to a recent study.
The study was designed to assess the risk associated with the overdetection of recurrence after primary treatment, and its findings pointed up the need to devise better methods of determining which men truly need salvage therapy, and when, an author said in a press release.
“Previous studies have indicated that the interval from prostate- specific antigen (PSA) recurrence to metastasis is quite long, with a median of more than 8 years, even in the absence of any treatment for the recurrence,” said Ruth Etzioni, PhD, full member of the Public Health Sciences Division at Fred Hutchinson Cancer Research Center in Seattle, Washington, in the release issued by the American Association for Cancer Research. “Given that the majority of prostate cancer patients are older, we expect that many would die of other causes before reaching the point of metastasis. Much like the issues with PSA screening and overdetection of prostate cancer, overdetection of recurrence after primary treatment poses some concerns as well.”
Primary among those concerns are the side effects of common salvage treatments, Etzioni said. She noted that radiation therapy can cause bowel problems and urinary symptoms, and that hormone therapy can spark hot flashes, fatigue, loss of libido, and late effects such as osteoporosis, heart disease, and diabetes.
For their study, Etzioni and colleagues gathered data from 441 prostate cancer patients treated at Johns Hopkins University, 4455 patients from the Cancer of the Prostate Strategic Urologic Research Endeavor database, and additional data from the Surveillance, Epidemiology, and End Results (SEER) registry.
They used the data to generate age and disease characteristics for 1 million virtual patients, and then looked at one specific factor among those men who experienced PSA recurrence and were not given salvage therapy: cases in which death from something other than prostate cancer came before metastasis from the disease.
The authors determined that at least 9.1% of prostate cancer patients whose PSA increases 5 years after initial treatment, and 15.6% of those whose PSAs rise 10 years after treatment, may not develop metastatic disease in their lifetime; therefore, they are overdetected for recurrence. Among the virtual patients older than 70 years who experienced a biochemical recurrence within 10 years of prostate cancer diagnosis, at least 31.4% were overdetected in the investigators’ model.
Xia J, Trock BJ, Gulati R, et al. Overdetection of recurrence after radical prostatectomy: estimates based on patient and tumor characteristics. Clin Cancer Res. 2014;20(20):5302- 5310.