A new study suggests active surveillance may be an initial approach for men with favorable intermediate-risk prostate cancer but further research results are needed, according to a study published online by JAMA Oncology.1
According to the National Comprehensive Cancer Network (NCCN) guidelines, active surveillance is considered for patients with low-risk prostate cancer and a life expectancy of at least 10 years. Active surveillance means monitoring the course of prostate cancer with the expectation to start treatment if the cancer progresses. No direct comparison has been made between favorable intermediate-risk and low-risk prostate cancer with regard to prostate cancer-specific mortality or all-cause mortality following high-dose radiotherapy such as brachytherapy (where radioactive seeds are placed near the tumor). The authors note such comparisons are clinically relevant because of the active surveillance guidelines for men with low-risk prostate cancer, according to the study background.
Ann C. Raldow, M.D., of Brigham and Women’s Hospital, Boston, and coauthors studied 5,580 men (midpoint age, 68 years) with localized prostate cancer treated between 1997 and 2013. They estimated and compared the risk of prostate cancer-specific mortality and all-cause mortality following brachytherapy among men with low and favorable intermediate-risk prostate cancer.
After a median of nearly eight years of follow-up, 605 men died (10.84 percent of the total group) and, among those, 34 men died of prostate cancer (5.62 percent of total deaths). The authors found that men with favorable intermediate-risk prostate cancer did not have a significantly increased risk of prostate cancer-specific mortality and all-cause mortality compared with men with low-risk prostate cancer. Eight-year estimates for prostate cancer-specific mortality were low at 0.48 percent for men with favorable intermediate-risk prostate cancer and 0.33 percent for men with low-risk prostate cancer. The estimates for all-cause mortality were 10.45 percent for men with favorable intermediate-risk prostate cancer and 8.68 percent for men with low-risk prostate cancer, according to the results.
“Despite potential study limitations, we found that men with low-risk PC [prostate cancer] and favorable intermediate-risk PC [prostate cancer] have similar and very low estimates of PCSM [prostate cancer-specific mortality] and ACM [all-cause mortality] during the first decade following brachytherapy. While awaiting the results of ProtecT, the randomized trial of AS [active surveillance] vs. treatment, our results provide evidence to support AS as an initial approach for men with favorable intermediate-risk PC [prostate cancer],” the study concludes.
In a related commentary2, Fred Saad, M.D., of the University of Montreal, Canada, writes: “Whether we can safely expand the concept of AS [active surveillance] to some patients with intermediate-risk prostate cancers has become a subject of interest to both physicians and patients. The study in this issue of JAMA Oncologyby Raldow et al compares low-risk to favorable intermediate-risk prostate cancer and shows that brachytherapy was equally effective, with a very low risk of mortality, in both groups. According to the authors, the findings suggest that some intermediate-risk patients may actually be good candidates for AS. This suggestion is interesting but requires careful reflection.”
“So what can we learn from this study by Raldow et al? One of the most important findings is that favorable intermediate-risk cancers can be very well controlled with brachytherapy. This is very worthwhile information. What about expanding the indications for AS? Although I am a urologist who has been practicing active surveillance for most of my low-risk patients for many years, I suggest that we continue to be very cautious, and extremely selective, in offering AS to patients with any features of intermediate-risk prostate cancer,” Saad concludes.
1. JAMA Oncol. Published online February 19, 2015. doi:10.1001/jamaoncol.2014.284.
2. JAMA Oncol. Published online February 19, 2015. doi:10.1001/jamaoncol.2014.103. A