The CAPRA score — which stands for “Cancer of the Prostate Risk Assessment” score — was developed at the University of San Francisco as a method to assess risk of prostate cancer progression based on risk for metastases or prostate cancer-specific mortality.
Here is how you calculate your CAPRA score, which is the sum of 5 different numbers:
- The first number is based on your PSA level before you ever have a biopsy that is positive for prostate cancer
- If the PSA is between 2.0 and 6.0 ng/ml, count 0 CAPRA points
- If the PSA is between 6.1 and 10.0 ng/ml, count 1 CAPRA point
- If the PSA is between 10.1 and 20.0 ng/ml, count 2 CAPRA points
- If the PSA is between 20.1 and 30.0 ng/ml, count 3 CAPRA points
- If the PSA is > 30 ng/ml, count 4 CAPRA points
- The second number is based on your Gleason score, available after your biopsy
- If your Gleason score is 3 + 3 = 6 or lower, count 0 CAPRA points
- If your Gleason score is 3 + 4 = 7 ((i.e., any secondary pattern 4 or 5), count 1 CAPRA points
- If your Gleason score is 4 + 3 = 7 or higher (i.e., any primary pattern 4 or 5), count 3 CAPRA points
- The third number is based on your clinical (not your pathological) stage
- If your clinical stage is T1c or T2, count 0 CAPRA points
- If your clinical stage is T3, count count 1 CAPRA point
- The fourth number is based on the percentage of your biopsy cores that were positive for cancer
- If the percentage of your biopsy cores that are positive is < 34 percent, count 0 CAPRA points
- If the percentage of your biopsy cores that are positive is ≥ 34 percent, count 1 CAPRA point
- The final, fifth number is based on your age
- If you are < 50 years of age, count 0 CAPRA points
- If you are ≥ 50 years of age, count 1 CAPRA point
What does this mean in practice?
Jim is a 52-year-old man whose father died of prostate cancer in his late 80s. Jim has been having regular PSA and DRE tests since he was 40. This year his PSA rose from a pretty stable level of 1.0 to 1.5 ng/ml up to 2.3 ng/ml, and Jim and his doctor decided he should talk to a urologist and consider the possibility of a biopsy. The urologist said, “Let’s keep an eye on the PSA before we rush into a biopsy,” and Jim was comfortable with that, but 3 months later his PSA was 3.1 ng/ml, and the urologist said, “Time to do the biopsy.” Jim agreed. The DREs had been consistently negative
The urologist did a 12-core biopsy and found a small amount of Gleason 3 + 4 = 7 cancer in one of two cores that were positive. The other positive core was Gleason 3 + 3 = 6. Both positive cores were in the lower, right-hand section of the right lobe of the prostate.
So what is Jim’s CAPRA score?
- His highest pre-positive biopsy PSA was 3.1, which scores 0 CAPRA points.
- His Gleason score was 3 + 4 = 7, which scores 1 CAPRA point
- His clinical stage is either T1c or T2a (depending on whether you assess it before or after the biopsy), which scores 0 CAPRA points
- The percentage of his biopsy cores that were positive for cancer is 2/12 = 16.7 percent, which scores 0 CAPRA points
- His age is 52, which scores 1 CAPRA point
- So Jim’s total CAPRA score is 0 + 1 + 0 + 0 + 1 = 2
But what does this mean?
According to a paper by May et al., this would suggest that 3 or 5 years after a radical prostatectomy, Jim’s risk of having a recurrence of his cancer would be between 6 and 8 percent. The original paper by Cooperberg and his colleagues was slightly less optimistic, giving a 5-year rate of biochemical recurrence-free survival of only 86 percent even for patients with CAPRA scores of 0 to 1.
However, the way that Cooperberg and his colleagues are now using CAPRA scores at the University of California San Francisco Medical Center is as a method to monitor patients on active surveillance. Patients with a low, stable CAPRA score would seem to be good candidates to be maintained on active surveillance for long periods of time. By contrast, a man with a rising CAPRA score might be a better candidate for treatment.
As we have suggested previously, this theory needs to be tested prospectively in clinical trials to see if the assumption behind this concept can be proven in clinical practice, but CAPRA scoring does give clinicians and patients a potentially promising method to monitor ongoing risk for those patients who have decided that immediate intervention is “not for them.”