Surveillance viable in carefully selected prostate cancer patients

Berlin-Active surveillance appears to be a safe option for carefully selected patients diagnosed with prostate cancer. However, changes in biopsy scheduling and technique may be needed to detect high-grade cases.

University of Miami researchers reported that more than one-fourth of patients diagnosed with prostate cancer who chose active surveillance experienced tumor progression. Progression was largely unrelated to family history of prostate cancer, PSA at diagnosis, or a negative biopsy before diagnosis, said the authors, whose findings were reported at the 2011 Société Internationale d'Urologie congress in Berlin and subsequently published in the Journal of Urology (March 14, 2012).

"The rate of progression was relatively stable over the first three sessions of surveillance biopsies," said senior author Viacheslav Iremashvili, MD, PhD, senior research associate at the University of Miami Miller School of Medicine. "We noticed a significantly increased risk of biopsy progression in African-American patients (p<.001) and also in small prostates (p<.001) with correspondingly high PSA densities (p<.001). Patients who had two positive cores in diagnostic biopsy also had an increased risk of progression (p<.001).

The active surveillance program included 272 patients with a mean age of 62 years. Of the patients, 249 had at least one surveillance biopsy, the median PSA was 5.1 ng/mL, mean number of surveillance biopsies was 2.3, and median follow-up was 2.9 years.

"It should be noted that our criteria for active surveillance are somewhat more conservative than at other institutes. We included patients with clinical stage T1-T2a, Gleason score 4/5, and no more than two positive biopsy cores with less than 20% tumor in any core," Dr. Iremashvili said.

The follow-up consisted of PSA testing and digital rectal examination every 3 to 4 months. The first surveillance biopsy was done at approximately 1 year following diagnosis, and then every 1 to 2 years. Progression was defined as changes in the Gleason score or tumor volume beyond the accepted limits.

Within 3 years of active surveillance mean duration follow-up, tumor progression was seen in 64 patients (26%), of which five (23%) had Gleason 4/5 cancer only, 21 (33%) had increase in tumor volume only, and 28 (44%) had both types of changes. Eight patients (3%) elected treatment in the absence of biopsy progression.

More progression in African-American men

More than half of the African-American patients progressed compared to less than 25% of Caucasians after 3 years of active surveillance.

"Although the cut-point value of PSA density [PSAD] of 0.15 divided patients into subgroups of somewhat higher and somewhat lower risk, the difference between these groups (with PSAD of <0.15 and ≥0.15) did not seem to be dramatic. Thus, the risk of biopsy progression, although strongly associated with PSAD, does not seem to rise substantially in patients with values of >0.15, and the association between the risk of progression and PSAD is linear," Dr. Iremashvili said.

Patients with tumor progression elected to undergo prostatectomy (n=32, 53%) and radiotherapy (n=27, 44%). Three patients elected to continue active surveillance despite biopsy progression.

"The possibility of sacrificing the 'window of curability' is the most important challenge limiting widespread acceptance of active surveillance," Dr. Iremashvili pointed out.