THE "NEW" PROSTATE CANCER INFOLINK

A new paper based on the cohort of patients being followed with active surveillance (AS) at Memorial Sloan-Kettering Cancer Center (MSKCC) has added to our understanding of the potentially optimal management of patients on AS. In assessing these data it is critical to bear in mind that AS is a management technique used to defer interventional treatment for an indeterminate period of time. It is not a treatment for localized prostate cancer in and of itself. For a pcroportion of men, however, it may permit treatment to be deferred for highly extended period of time, as demonstrated by Klotz and his colleagues.

Adamy et al. report data from a series of 238 patients who met all institutional criteria for eligibility in the MSKCC active surveillance protocol and who have been analyzed for progression over time. The MSKCC eligibility criteria require a patient to have a PSA < 10 ng/ml, no Gleason grade 4 or 5 tissue on biopsy, a clinical stage of T1–T2a, three or fewer positive biopsy cores (out of a minimum of 10 cores in total), no biopsy core containing more than 50 percent cancer involvement, and a confirmatory biopsy to reassess eligibility before starting AS. The 238 patients who met all institutional criteria and elected to start on AS were enrolled between September 1997 and February 2009.

As a general rule, patients were re-assessed twice a year using a digital rectal examination (DRE) , free and total PSA measurements, and a review of their general health and urinary symptoms. A first follow-up biopsy was customary 12 to 18 months after starting AS and every 2 to 3 years thereafter, unless prompted by a change in DRE findings or a sustained PSA increase. Treatment was offered when patients no longer met study eligibility criteria during follow-up. An increase in a patient’s PSA level was generally considered an indication for a repeat biopsy as opposed to immediate intervention.

Adamy et al. evaluated their patients based on two sets of criteria:

• The standard criteria, under which patients had to continue to meet all of the original study entry criteria
• A set of modified criteria, under which patients had to continue to meet all of the original study entry criteria except one — their PSA could rise to 10 ng/ml or higher.

Here are the results of their analysis:

• The median age of patients at time of study entry was 64 years.
• When evaluating patients based on the standard criteria
  • 86/238 men (36.1 percent) either received treatment or had progressed at a subsequent follow-up.
  • Median follow-up in men who did not progress was 1.8 years.
  • 27/238 men (11.3 percent) were followed for at least 5 years.
  • The 2- and 5-year probabilities of  meeting all standard criteria were 80 and 60 percent, respectively.
• When evaluating patients based on the modified criteria
  • 64/238 men (26.9 percent) either received treatment or had progressed at a subsequent follow-up.
  • Median follow-up in men who did not progress was 1.9 years.
  • 32/238 men (13.4 percent) were folowed for at least 5 years.
  • The 2- and 5-year probabilities of  meeting all standard criteria were 91 and 76 percent, respectively.
• Baseline PSA was an independent predictor for AS failure only when PSA level was also used as a criterion for progression
• Patients with no cancer detected on confirmatory biopsy were less likely to progress during follow-up.

This group of researchers has previously demonstrated the importance of a confirmatory biopsy before patients are entered onto an AS protocol. Based on their data from the current analysis, Adamy et al. further conclude that:

• Most patients show little evidence of progression within 5 years.
• There is minimal justification for treatment of men on AS based exclusively on PSA increases above 10 ng/ml unless there are other clear indications of tumor progression.

The authors acknowledge that their data are based on a relatively small patient sample followed for a limited period of time, but their careful analysis would seem to have value in developing the “best” possible protocol for the long-term use of active surveillance.

Filed under: Diagnosis, Management, Risk | Tagged: active surveillance, AS, follow-up, outcome |