Originally developed in 1998 by a medical researcher named D’amico, this classification system is designed to evaluate the risk of recurrence following localized treatment of prostate cancer. It categorizes patients into three risk-based recurrence groups: low, intermediate, and high risk, using such measures as blood PSA levels, Gleason grades, and tumor stages via T-scores.
As such, it could potentially help you make a more informed prostate cancer treatment decisions. There are many factors to take into account when making a decision regarding prostate cancer treatment, including the consideration of long-term quality of life. All currently available prostate cancer treatments carry some level of risk for complications or side effects. These impacts vary for each patient, but are important aspects to keep in mind when choosing a treatment option.
However, many patients and their loved ones struggle with these decisions because the probability of cancer recurrence is not definitely known. The D’amico risk group classification system was developed to estimate the likelihood of recurrence for any patient using a given set of parameters, and is widely used as one of many individualized risk assessment tools. This analysis could help those battling prostate cancer to make a more informed decision regarding their treatment. But how does the system work, and can it really predict the probability of recurrence?
How the System Works
First, let's look at how it works. Men with:
- Low risk: Have a PSA less than or equal to 10, a Gleason score less than or equal to 6, or are in clinical stage T1-2a
- Intermediate risk: Have a PSA between 10 and 20, a Gleason score of 7, or are in clinical stage T2b
- High-risk: Have a PSA more than 20, a Gleason score equal or larger than 8, or are in clinical stage T2c-3a. (UCSF 2011)
What the Research Says About the System
Second, here's what the research says about the veracity of the D’amico classification system:
Two studies that included more than 14,000 prostate cancer cases from 1984 to 2005 looked at the ability to predict cancer specific and overall survival rates in these patients as well as the clinical relevancy of such a risk-based classification system in contemporary medicine.
The studies estimated survival rates after surgery with a method called the Kaplan-Meier method. This analysis calculates the “biochemical recurrence-free survival (BRFS)” (meaning survival from prostate cancer without a high enough PSA level to call it a cancer recurrence) rates in patients in varying stages of cancer. Those predicted survival rates were then compared to the actual cases to see if using the D’amico risk-based classification system helped the patient make a more informed treatment decision and therefore increased chances of survival.
The studies found that men who had more prognostic information available to them (such as the D’amico risk-based classification system) had overall higher survival rates following treatment for their prostate cancer, particularly those men with a high risk of recurrence.
However, the system is not able to accurately evaluate the risk of recurrence in those men with multiple risk factors. As prostate cancer cases with multiple risk factors are on the rise, the D’amico classification system may not be as relevant to men with prostate cancer and their doctors as other evaluation techniques.
Bottom line: The D'amico system does seem helpful and it's worth knowing about. As always, it is important to discuss all possible care options with your doctor before making a final treatment decision.
Boorjian SA, Karnes RJ, Rangel LJ. Mayo Clinic validation of the D'amico risk group classification for predicting survival following radical prostatectomy. J Urol. 2008 Apr;179(4):1354-60; discussion 1360-1. Epub 2008 Mar 4.
Hernandez DJ, Nielsen ME, Han M. Contemporary evaluation of the D'amico risk classification of prostate cancer. Urology. 2007 Nov;70(5):931-5.