Active Surveillance May Be Preferred Option in Some Men with Prostate Cancer
Posted Apr 23 2011 10:34pm
Active Surveillance May Be Preferred Option in Some Men with Prostate Cancer
A diagnosis of very-low-risk prostate cancer means it is highly unlikely to become a clinically significant, life-threatening cancer.
Findings of a recent study, the largest and longest of its kind, provide strong evidence supporting a conservative approach to managing prostate cancer in some men. The study was not a randomized clinical trial ; rather, it was a long-term analysis of a cohort of men diagnosed with what is called very-low-risk prostate cancer. Instead of immediately undergoing surgery or radiation therapy, the men had opted to undergo a process known as active surveillance at the Johns Hopkins University School of Medicine.
A diagnosis of very-low-risk prostate cancer means that the disease is highly unlikely to become a clinically significant, life-threatening cancer. These men could be safely monitored by active surveillance, the study found, with only a modest percentage eventually requiring some form of treatment and none dying from prostate cancer. The results were published online April 4 in the Journal of Clinical Oncology (JCO).
As is the case with prostate cancer in general in the United States, most of the men in the study were 65 or older. The results provide very strong evidence that active surveillance is the “preferred option” for most men in this age group with very-low-risk disease, said the study’s senior investigator, Dr. H. Ballentine Carter. In fact, he continued, “The overwhelming evidence says that for men over 65 who are diagnosed with low-risk disease, their first question should be whether any therapy is appropriate for them, not which therapy.”
The clinical relevance of the findings is hard to overstate, Dr. Carter stressed. Among the 217,000 men in the United States diagnosed each year with prostate cancer, a substantial proportion has very-low-risk or low-risk disease. The vast majority of these men immediately undergo some form of treatment, including men aged 75 and over, despite the fact that many would be unlikely to experience significant symptoms, let alone die from prostate cancer.
Defining Very-Low-Risk Prostate Cancer
The Johns Hopkins definition of very-low-risk prostate cancer is similar to the NCCN definition. For the study in JCO, very-low-risk was defined as:
Clinical stage T1c (no palpable disease, biopsy recommended based on abnormal PSA)
Gleason score of 6 or less
PSA density (ratio of PSA level to prostate gland size) of 0.15 ng/mL or less
Two or fewer biopsy cores in which cancer is present, and less than 50 percent cancer present in any involved core
Patient Selection, Compliance Are Key
At Hopkins, the active surveillance program involves a semi-annual check-up and an annual biopsy . Patient selection is very important, Dr. Carter explained.
Among the 769 men enrolled in Hopkins’ active surveillance program between 1995 and 2010, approximately 80 percent had very-low-risk disease. Whether a patient has very-low-risk disease is determined based on factors such as the Gleason score (a common measure of tumor aggressiveness) and the extent of cancer in the biopsy samples, or cores, from the prostate gland. (See the sidebar for all of the factors.)
The remaining men had at least one biopsy feature that precluded their disease from being considered very-low-risk, Dr. Carter explained. These men were typically older and had other health problems, he continued, which made active surveillance more attractive than treatment with surgery or radiation, both of which can have significant side effects.
Compliance with the approach has been quite strong, the Hopkins team reported, with nearly 90 percent of participants completing their annual biopsies.
Although no men in the study died of prostate cancer, 255 did undergo some form of treatment, 74 percent of whom did so because their disease was reclassified based on the findings of an annual biopsy.
Overall, 41 percent of men in the study did not require any form of treatment, even after 10 years of follow-up, a “remarkable” finding, said Dr. Bhupinder Mann from NCI’s Division of Cancer Treatment and Diagnosis . “This study adds to the accumulating evidence that, in carefully selected patients, active surveillance is safe.”
The results “strongly support” recent revisions to prostate cancer treatment guidelines from the National Comprehensive Cancer Network (NCCN), said the guidelines’ panel chair, Dr. James Mohler from the Roswell Park Cancer Institute. Updated last year , the guidelines recommend that physicians advise men with very-low-risk disease who have a life expectancy of up to 20 years to pursue active surveillance.
Findings like these on active surveillance, combined with related research on the growing problem of overdiagnosis and overtreatment of prostate cancer linked to PSA screening, appear to be reaching down into the community setting, Dr. Mohler believes.
“I think men and their doctors are becoming more educated about the overtreatment issue,” he said.
As evidence, Dr. Mohler pointed to the START trial , a phase III clinical trial being led by NCI-Canada, in collaboration with the U.S. NCI, in which men diagnosed with very-low-risk or low-risk disease are being randomly assigned to active surveillance or immediate treatment. When the trial opened in 2007, most men who declined to enroll did so because they did not want to take the risk of being assigned to the active surveillance arm. “Now most men are declining to participate because they want active surveillance,” Dr. Mohler said.
Having a strong system in place to ensure that men pursuing active surveillance are followed and receive reminders for their check-ups and biopsies is extremely important, Dr. Carter stressed.
At the moment, the Hopkins surveillance program is managed primarily by an administrator using a manual process. But the program is moving to a Web-based approach for monitoring and following patients, he added.
Approaches Can Vary
Although the evidence in favor of active surveillance continues to accumulate, the optimal approach to managing the process is not yet defined, Dr. Mann noted. This is particularly true with respect to how patients’ disease is tracked.
At Hopkins, men are followed via check-ups and annual biopsies. Any reclassification of their disease is typically based on biopsy findings, such as a change in Gleason score, which might then produce a recommendation for treatment. But many other centers, such as Roswell Park, do not require men who choose active surveillance to undergo regular biopsies. Rather, they use some form of what is commonly called PSA kinetics, which are changes in PSA levels over time (for instance, how long it takes for PSA levels to double).
Results from several studies, however, have raised doubts about the value of PSA kinetics in initially identifying or managing prostate cancer. Based on their experience, PSA kinetics is “not reliable for predicting the presence of high-grade cancer on an individual basis,” the Hopkins team wrote in JCO. “Thus, if the goal of surveillance is to identify and treat higher-risk cancers, we believe that annual biopsies may be necessary to ensure patient safety.”
But regular biopsies are by no means without their own risks. A small percentage of men end up in the hospital with antibiotic resistant infections as a result of a prostate biopsy, Dr. Mohler said, and repeat biopsies can lead to inflammation and scar tissue formation that can preclude nerve-sparing surgery to treat the prostate cancer in some men whose disease progresses.
According to Dr. Carter, Hopkins researchers are now studying whether men who have had two consecutive biopsies that show no evidence of disease progression can safely have the interval between routine biopsies extended. In the meantime, the NCCN guidelines are being revised again, Dr. Mohler said, using data from large active surveillance programs at Hopkins, the University of Toronto, and the University of California, San Francisco, to provide recommendations on managing men who choose this conservative approach.
Further clarity on this matter should be forthcoming, Dr. Mann said. In addition to the START trial, which will follow men using both PSA measures and prostate core biopsies, a similar trial is being conducted in the United Kingdom that is using only PSA levels to monitor patients. Also, in December, NCI and CDC are sponsoring an NIH State-of-the-Science Conference to review the role of active surveillance in managing localized prostate cancer and to help guide future research in this area.