THE "NEW" PROSTATE CANCER INFOLINK

Traditionally, we have believed that a small but significant percentage of men with organ-confined, Gleason 6 prostate cancer would have biochemical progression after a radical prostatectomy. New data from Johns Hopkins suggest that such disease progression should be extremely rare.

Miyamoto et al. identified 2,551 patients who received radical prostatectomies at Johns Hopkins between 1983 and 2005 and who, at the time were coded by the urologists as having pathologically organ-confined, Gleason score 6 cancer with more than 1 year of follow-up.

The authors carried out a histopathological re-examination of the serially sectioned and completely embedded radical prostatectomy specimens of 38 men who developed biochemical recurrence — defined as a single PSA level of ≥ 0.2 ng/ml. The results of this re-examinations showed that:

• In 27/38 cases (71 percent), the patients had a higher Gleason grade or a higher clinical stage than coded by the urologists.
• 10 patients had organ-confined disease with Gleason pattern 4 as either the primary or secondary pattern.
• 9 patients had organ-confined disease with Gleason score 6 but with tertiary Gleason pattern 4 (and in 4 cases the tertiary pattern 4 was described in the initial pathology report).
• 5 patients had a Gleason score of 7 together with extraprostatic extension.
• 1 patient had a Gleason score of 6 with focal extraprostatic extension.
• 2 patients had positive surgical margins due to intraprostatic incision (listed in the initial pathology report).
• 11/38 cases (29 percent) had true organ-confined, Gleason score 6 tumors, and none of these 11 patients developed systemic disease.

The authors conclude that most prior reports of organ-confined, Gleason score 6 with progression have, in fact, been undergraded, understaged, or situations with ambiguous staging. They go on to say that, “Even for the rare true organ-confined, Gleason score 6 (no pattern 4) tumor with supposed biochemical progression, some may be false-positive progression based on low post-radical prostatectomy prostate-specific antigen levels and minute tumors that seem highly improbable to progress.”

Their “take-away” from this study is that, “With accurate pathologic evaluation, men with organ-confined, Gleason score 6 (no pattern 4) prostate cancer can be told that their risk of progression is very rare,” and they estimate that only anout 4 men in 1,000 (0.4 percent) who meet these criteria are at risk for progression after radical prostatectomy. The great unanswered question, of course, is how many men with truly organ-confined, Gleason 6 prostate cancer need treatment at all — as compared to conservative management, and is there a good way to identify these patients more accurately?