On 2013 Jun 19, Jim Brooks commented:

In a radical prostatectomy cohort at our institution, we have noted no deaths in men with Gleason score 3+3=6 prostate cancer in long term follow-up (Brooks JD et al. The Open Prostate Cancer Journal 1:1, 2008). Walsh and Epstein recently published 30 year follow-up at Johns Hopkins, and noted only a single death in patients with Gleason score 6 prostate cancer (Mullins JK et al, J. Urol 188(6):2219, 2012). Interestingly, in that set of patients 5 were scored as having lymph node metastases and it appears that 1 of these patients died of prostate cancer. It is highly likely (or certain) that those 5 patients scored as having lymph node metastases were re-classified by Dr. Epstein as Gleason score 7 or above in the above study. It would have been much more useful, although a lot of work, if the pathologists regraded all cases in this study, rather than only those with lymph node metastases. However, this paper does provide an important insight into Gleason score 6 cancer: it does not have the capacity to metastasize. When coupled with the studies with long term follow-up, it also appears that Gleason score 6 cancer is not lethal, regardless of tumor volume. It will be critical to understand the mechanisms and frequency of the transition of Gleason score 6 to higher grades of prostate cancer.

On 2013 Jun 19, Jim Brooks commented:

In a radical prostatectomy cohort at our institution, we have noted no deaths in men with Gleason score 3+3=6 prostate cancer in long term follow-up (Brooks JD et al. The Open Prostate Cancer Journal 1:1, 2008). Walsh and Epstein recently published 30 year follow-up at Johns Hopkins, and noted only a single death in patients with Gleason score 6 prostate cancer (Mullins JK et al, J. Urol 188(6):2219, 2012). Interestingly, in that set of patients 5 were scored as having lymph node metastases and it appears that 1 of these patients died of prostate cancer. It is highly likely (or certain) that those 5 patients scored as having lymph node metastases were re-classified by Dr. Epstein as Gleason score 7 or above in the above study. It would have been much more useful, although a lot of work, if the pathologists regraded all cases in this study, rather than only those with lymph node metastases. However, this paper does provide an important insight into Gleason score 6 cancer: it does not have the capacity to metastasize. When coupled with the studies with long term follow-up, it also appears that Gleason score 6 cancer is not lethal, regardless of tumor volume. It will be critical to understand the mechanisms and frequency of the transition of Gleason score 6 to higher grades of prostate cancer.