Here it is.
February 21, 2011 (Orlando, Florida) — Is it reasonable to discontinue prostate-specific antigen (PSA) testing 10 years after radical prostatectomy if the patient has remained disease-free to that point?
Stacy Loeb, MD, a urology resident at Johns Hopkins University, in Baltimore, Maryland, presented the findings here at the 2011 Genitourinary Cancers Symposium.
"A lot of issues are addressed by prostate cancer guidelines," Dr. Loeb told Medscape Medical News in an interview. "But one issue not addressed is how long patients need to continue PSA testing after radical prostatectomy."
Results from the largest study carried out to date — and with the longest follow-up — suggest that the answer is yes.
Previous studies have shown that biochemical recurrence usually occurs within 5 years of surgery; even when cancers return after 5 years, they're usually associated with less risk for morbidity and mortality.
This retrospective study followed 10,609 men from the Hopkins database, some for as long as 25 years after surgery. Dr. Loeb reported that 1,684 men in the cohort had biochemical recurrences, defined as a PSA level above 0.2 ng/mL, without previous hormonal or radiation therapy.
Dr. Loeb said that 77% of the recurrences occurred within 5 years of surgery, 16.6% occurred 5 to 10 years after surgery, 4.9% occurred 10 to 15 years after surgery, and 1.5% occurred more than 15 years after surgery.
"Late recurrences were associated with more favorable pathologic features," Dr. Loeb said. "Even when cancers did recur, they were unlikely to metastasize or cause the patient to die from prostate cancer."
Having a low initial Gleason score was a favorable factor, she said. "No patient with a Gleason [score of] 6 or less had metastases or death, even if they had late recurrence. So for those men, and also for men with a limited life expectancy, it's probably safe to discontinue PSA testing 10 years after surgery."
Dr. Loeb concluded that "men who remain disease-free 10 years after surgery should be counseled that their risk of subsequent cancer-related morbidity and mortality is low."
Jonathan Tward, MD, a radiation oncologist at the Huntsman Cancer Institute in Salt Lake City, Utah, said that he found the study very useful. "It's not like a lot of studies where it's unclear how to translate the findings to clinical practice. This directly guides physicians as to what they can tell patients."
He noted that prostate cancer is associated with a lot of anxiety before treatment, but also after treatment. "Every few months when PSA is drawn, it causes patients a lot of worry; it can be almost like a [posttraumatic stress disorder], quite frankly. So knowing when you can safely stop testing is really important information."
Both Dr. Tward and Dr. Loeb did stress, however that in very young patients it's probably a good idea to continue testing beyond 10 years. "If you have a very young patient, I'd be wary of stopping after 10 years, because there's still a lot of potential for bone metastases in those patients," Dr. Tward said. "Even looking at data going out 20 years, it may only be a few who will develop metastases, but you don't want them having to live with that risk."
Both physicians also agreed that rather than stopping PSA testing completely after 10 years, a reasonable option might be to continue to testing, but at much less frequent intervals. "Frankly, anything more frequent than once a year seems like overkill," Dr. Tward said.