A second set of data have just been published from a major academic institution that show significant pre-surgical underestimation of Gleason scores (based on biopsy cores) compared to the postsurgical values (based on pathologic evaluation of the entire prostate). As with the data previously published by the University of Miami group, these data from Duke University show an improvement in the percentage of patients who were accurately graded in the period 2000 to 2006 (50.7 percent) compared to the percentage accurately graded between 1988 and 1999 (41.4 percent) . However, based on these data about half of the patients being treated at Duke were still being misstaged over the past 6 years, which is probably as disappointing for the Duke staff as it is for their patients.
The Duke database included 2,963 patients receiving a radical prostatectomy between 1988 and 2006. They were divided into two groups according to year of diagnosis: 1988 to 1999 and 2000 to 2006. The Gleason sum discrepancies were evaluated in the above groups. The predictive roles of diagnostic age (less than 50, 50 to 60, 60.1 to 70, and greater than 70 years), PSA level (less than 10, 10 to 20, and greater than 20 ng/mL), race, body mass index, and prostate weight on the discrepancies were analyzed.
The results presented by the Duke group are as follows:
Overall, 55.8 percent of diagnostic Gleason sums differed from those on final surgical pathology (58.6 percent in the 1988 to 1999 and 49.3 percent in the 2000 to 2006 groups).
Diagnostic Gleason sums were undergraded in 41.2 percent of cases and overgraded in 12.8 percent of cases.
Men older than 60 years of age were more likely to have their diagnostic Gleason sums undergraded than men younger than 50.
Biopsy Gleason sums in men with a high PSA level (≥ 10 ng/mL) were more likely to be undergraded than in men with a lower PSA level (< 10 ng/mL)
In addition to the obvious conclusions that there is still a high level of undergrading, the authors also suggest that advanced age and high PSA levels may be predictive of diagnostic Gleason sum undergrading, and that, consequently, physicians should exercise caution when recommending active surveillance in older men.