Correlation between biopsy and surgical Gleason scores
Posted Sep 29 2008 5:55pm
Clinicians at the University of Miami have just reported on changes in the correlation between pre-surgical (biopsy) Gleason scores and post-surgical Gleason scores over a 15-year period, based on the surgical treatment of 1670 men at their institution.
The authors divided the patients into three groups by year, and 1363 of the patients met eligibility criteria for analysis:
Group 1: 1992-1996
Group 2: 1997-2001
Group 2: 2002-2006
The results of the study clearly show that over the 15-year time period there was a meaningful improvement in the correlation between pre-surgical and post-surgical Gleason score, as follows:
Group 1: 58 percent
Group 2: 66 percent
Group 3: 75 percent
and in 937 patients there was precise correlation betwen the pre-surgical and post-surgical grades.
However, it is worth noting that, based on these data, many patients still are not accurately graded at the time of the initial biopsy, and (according to the authors) the majority of these patients are undergraded (361/1363, 26 percent) as opposed to overgraded (65/1363, 5 percent).
These data confirm the well known fact that accurate grading of patients prior to surgery can be extremely difficult. Patients who are told they have Gleason scores of 5 or 6 prior to surgery should be aware that there is a significant risk of undergrading, and good clinicians are likely to advise their patients accordingly. On the other hand, it is also clear that experience within a specific institution tends to improve the ability of a team to estimate patients’ Gleason grades more accurately. It would be interesting to know if other institutions are reporting similar trends in accuracy of their pre-surgical and post-surgical grading capabilities.