Several reports have clearly shown that biochemical recurrence (a rising PSA) after first-line treatment is more common among men with a Gleason score of 4 + 3 = 7 than it is in men with a Gleason score of 3 + 4 = 7. However, there has been no confirmation of an association between these Gleason scores and risk for prostate cancer-specific death.
Wright et al. have now published a retrospective analysis of data from 753 men aged between 40 and 64 years of age who were diagnosed with prostate cancer between 1993 and 1996 in King County, Washington. Prostate cancer recurrence and/or progression was determined by using a follow-up survey and medical record review. Mortality and cause of death were obtained from the Seattle-Puget Sound Surveillance, Epidemiology and End Results (SEER) registry.
The study showed that:
- 65/753 patients (8.6 percent) actually died of prostate cancer during a median follow-up of 13.2 years.
- The 10-year prostate cancer-specific survival rate categorized by Gleason score was as follows:
- Gleason score 6 or less — 98.4 percent
- Gleason score 3 + 4 = 7 — 92.1 percent
- Gleason score 4 + 3 = 7 — 76.5 percent
- Gleason score 8-10 – 69.9 percent
- Compared to patients with Gleason 3 + 4 disease, those with Gleason 4 + 3 tumors were at significantly increased risk for prostate cancer-specific mortality.
- Compared to patients with Gleason 3 + 4 disease undergoing curative therapy with radical prostatectomy or radiation therapy, those with Gleason 4 + 3 tumors had an increased risk for recurrence and/or progression and prostate cancer-specific mortality.
- There was no observable difference in prostate cancer specific-mortality between patients with Gleason 4 + 3 tumors and those with Gleason 8-10 tumors.
The authors conclude that (in men diagnosed with localized prostate cancer between 40 and 64 years of age) tumors with Gleason scores of 3 + 4 and 4 + 3 tend to have different impact on prostate cancer specific mortality, and that these data “provide important information for counseling patients with Gleason 7 prostate cancer on the natural history of the disease.”
While The “New” Prostate Cancer InfoLink would like to see these data confirmed through analysis of data from another population-based series of patients, we feel that this is an important analysis which does certainly confirm that Gleason 4 + 3 = 7 tumors behave more like Gleason 8-10 tumors, even with respect to the potential impact on prostate cancer-specific mortality. On the other hand, we would also emphasize that, based on the same set of data, the 10-year prostate cancer-specific survival rate of even the patients with Gleason scores of 8-10 was only fractionally under 70 percent.
It should also be noted that men diagnosed with clinically localized prostate cancer between 1993 and 1996 were probably at significantly greater risk for pathologically non-localized disease than men being diagnosed with clinically localized disease today. This suggests that men being diagnosed with Gleason 4 + 3 or Gleason 8-10 disease today may have a significantly greater probability of 10-year prostate cancer-specific survival than comparable men being diagnosed in the mid-1990s.