Nearly three-quarters of men with slow-growing prostate cancer who decide on active surveillance are not receiving the appropriate follow-up and might be missing signs of tumor worsening, according to a recent retrospective study from Australia.
The study, “Active surveillance of men with low risk prostate cancer: evidence from the Prostate Cancer Outcomes Registry–Victoria,” was published in the Medical Journal of Australia.
Prostate cancer is the second most common cancer in men worldwide after skin cancer. Most localized prostate cancer is slow-growing and slow to spread — called low-risk prostate cancer — and may not need treatment or shorten a man’s life.
Because of that, active surveillance, a monitoring option that allows the screening of any signs of tumor growth or worsening before surgical removal or therapy, is highly recommended in these cases.
This way, if the cancer does not progress, patients can avoid unnecessary invasive surgery and other burdensome treatments that might have side effects.
About 70% of men with low-risk prostate cancer who adhere to active surveillance will not need additional treatment, whereas the other 30% will have disease progression.
But even though these patients have a low risk of cancer progression and spread, it is essential that they are closely monitored through active surveillance, consisting of periodic biopsies of prostate tissue and blood tests to assess prostate specific antigens (PSA).
The numbers of patients adhering to accepted active surveillance protocols has increased over the years. Sweden may currently hold the highest percentage of patients opting for it, at 74%. However, less than 30% of patients in Europe and less than 13% in the U.S. have been reported to have the appropriate follow-up measures.
To assess how many of these prostate cancer patients in Victoria, Australia, fully adhere to active surveillance, their characteristics, and the factors associated with good adherence, researchers analyzed data from the Prostate Cancer Outcomes Registry–Victoria (PCOR-Vic).
The PCOR-Vic was established in 2009 to improve knowledge about treatments and outcomes for men diagnosed with prostate cancer in the state of Victoria, Australia.
Researchers analyzed the data of 1,635 men age 75 or younger at diagnosis, between August 2008 and December 2014, whose cancer was classified as grade group 3 or less as determined by the International Society of Urological Pathology (ISUP), and managed through active surveillance for at least two years.
The accepted active surveillance follow-up protocol was defined as at least one follow-up biopsy and three PSA blood tests over a two-year period.
Patients’ mean age at diagnosis was 64; 1,222 (74.7%) were diagnosed through transrectal ultrasound guided (TRUS) biopsy, and 1,102 (84%) had prostate cancer classified as ISUP grade group 1 (the most favorable disease state).
Only 433 patients (26.5%) followed the appropriate active surveillance protocol, leaving 1,202 men (73.5%) at a higher risk of missing a potential cancer progression.
Among all participants, 877 (53.6%) had at least one follow-up biopsy, and 601 (36.8%) underwent at least three PSA blood tests, while biopsy and PSA assessment were not conducted in 626 men (38.3%) and 80 (4.9%), respectively, within the two years after diagnosis.
Additional analysis showed that men diagnosed in private hospitals were more likely to fully adhere to adequate active surveillance than those diagnosed in public hospitals.
Among the factors associated with poor adherence were diagnosis through transurethral resection of the prostate (TURP) or transperineal biopsy (compared with TRUS biopsy), and being 66 or older at diagnosis (compared with younger than 55).
The team noted that additional studies to better understand the reasons behind poor adherence are needed, as well as an education campaign for patients and doctors highlighting the importance of active surveillance in these patients.