Understanding the D'Amico Classification System for Prostate Cancer

The D'Amico classification system is one of the most widely used approaches for assessing prostate cancer risk. Originally developed in 1998 by Anthony D'Amico, MD, PhD, a professor of radiation oncology at Harvard Medical School and chief of the Division of Genitourinary Radiation Oncology at Brigham and Women's Hospital and Dana-Farber Cancer Institute, this classification system is designed to evaluate the risk of recurrence following localized treatment of prostate cancer.

The system 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.

Function and Importance

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.

By defining your prostate cancer as being part of one of these three groups, this system could potentially help you and your healthcare provider make more informed treatment decisions. There are many factors to take into account when making a decision regarding prostate cancer treatment, including long-term quality of life and other risk factors or chronic health conditions you may have.

How the System Works

First, it's important to gather your numbers:

• PSA: The results of your PSA test, a blood test that detects prostate-specific antigen—a protein produced by the cells in your prostate
• Gleason score: The results of your Gleason score, given based on the microscopic appearance of your cancer cells
• Clinical stage T score: And your T stage, the size of your tumor as seen on an ultrasound or during a rectal exam

Using these numbers, your risk is either categorized as:

• Low risk: Those with 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: Those with a PSA between 10 and 20, a Gleason score of 7, or are in clinical stage T2b
• High-risk: Those with a PSA of more than 20, a Gleason score equal or larger than 8, or are in clinical stage T2c-3a.

What the Research Says

Two studies that included more than 14,000 prostate cancer cases looked at the ability to predict cancer-specific and overall survival rates as well as the clinical relevance 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 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 healthcare providers as other evaluation techniques.