Data Validate Active Surveillance Use
Findings from two studies add to growing evidence supporting the use of active surveillance for selected patients with prostate cancer (PCa).
In one study, Allison S. Glass, MD, and collaborators at the University of California in San Francisco (UCSF) reviewed data from 691 PCa patients undergoing active surveillance, 93% percent of whom were Caucasian.
On repeat biopsy, 206 (30%) had an upgrade in Gleason score and 123 (18%) were found to have increased volume to more than 33% of cores cancer positive.
After a median follow-up of 50 months, 36% of the overall cohort had delayed intervention: 22% underwent radical prostatectomy (RP), 10% had radiotherapy, and 4% received androgen deprivation therapy. Active treatment was prompted by biopsy progression (56%), PSA doubling time within 36 months (4%), or patient choice based on other clinical characteristics or personal preference (40%). Treatment-free survival at five years was 62%.
For 155 men who underwent RP, four-year PSA recurrence-free survival was 83%. Five-year disease-specific survival was 100% and overall survival was 98%.
The researchers noted that their cohort's rate of treatment intervention is similar to that found in previous studies and is most often done in response to grade migration. At intermediate follow-up, active surveillance appears safe, they concluded.
Of the entire cohort, 64% met UCSF's strict active surveillance selection criteria (cT stage T2a or less; PSA less than 10 ng/mL; diagnostic Gleason score of 6 or less without pattern 4 or 5; less than 33% cores positive; and less than 50% of a single core with cancer). Two-thirds of subjects had clinical T1 disease and the median PSA level at diagnosis was 5.3 ng/mL. The study population was 93% Caucasian.
Delayed vs. immediate RP
In the other study, Raj Satkunasivam, MD, and colleagues at the University of Toronto found that RP following a period of active surveillance for men with low-risk PCa does not result in adverse pathologic outcomes relative to patients with comparable preoperative pathology who underwent immediate RP.
Compared with low-risk patients undergoing immediate RP, however, patients who undergo RP after active surveillance are more likely to have higher-grade disease and extracapsular extension, they concluded.
Of 288 patients on active surveillance, 42 (14.5%) underwent RP mostly because of evidence of progression. The researchers referred to these patients as the ASRP group. These patients were compared with 132 age- and PSA-matched controls who underwent immediate RP (occurring within six months of the diagnosis of low-risk disease [Group 1]). In addition, the researchers compared 25 ASRP patients progressing to Gleason 7 disease while on active surveillance to 73 age- and PSA-matched cohort of de novo Gleason 7 disease treated with immediate RP (Group 2).
Compared with Group 1, the ASRP group had a higher proportion of patients with Gleason 7 disease (66.7% vs. 40.2%), pT3 and pT4 disease (33.3% vs. 14.7% and 7.2% vs. 0.8%, respectively), and extracapsular extension (26.2% vs. 11.4%). Active surveillance patients treated with RP after progressing to Gleason 7 disease did not differ significantly from Group 2 patients with respect to adverse pathologic outcomes.