D’Amico Prostate Cancer Risk Calculator

D’Amico risk clasification explained

The D’Amico risk clasification allows clinicians to make informed treatment decisions regarding cancer recurrence, in the case of patients who are about to undergo or have underwent treatment of prostate cancer.

The following table introduces the scoring method:

Raised levels of the prostate-specific antigen (PSA) are usually indicative of malignancy, however, this indicator cannot be used as sole diagnosis.

The Gleason score represents the score of the biopsy (primary or secondary) and is based on the architectural pattern on the glands and the degree in which the cells from the sample resemble normal cells.

The clinical TNM T staging indicates how large and spread the prostate neoplasm is. T1 tumors are small, T2 tumors are larger and are differentiated in T2a, T2b and T2c, depending on how they are localized in the gland. T3 stage tumors spread through the glandular capsule.

The UCSF-CAPRA score is another prostate cancer risk model which is based on research by the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE).

Result interpretation

There are three risk categories, as follows:

■ Low risk patients have: PSA less than or equal to 10 ng/mL, a Gleason score less than or equal to 6 and a clinical stage T1-2a. In this case, the prostate neoplasm is growing at a slow rate. This is unlikely to spread to other tissues in the following years. However, even in this case, monitoring through frequent ultrasounds, imagistic methods or biopsies, is still recommended.

■ Intermediate risk patients have: PSA between 10 and 20 ng/mL, a Gleason score of 7 and clinical stage T2b. However, cases in which the clinical stage is T1-2a but the PSA is between 10 and 20, regardless of Gleason being lower than 7 or 7 still enter in this category. The prostate cancer is growing at a moderate rate and even in this case, is unlikely to spread in the following years. In complex cases, medication, radiation therapy or surgery may still be required.

■ High risk patients have: PSA more than 20 ng/mL, a Gleason score equal or larger than 8 or clinical stage T2c, T3a. Similar to the intermediate risk category, when any of the above three is present, regardless of the situation with the other two, the patient fits in the high risk category. In this case, the glandular tissue has changed architecture with poorly differentiated cells that are loosing their normal function. The neoplasm is likely to spread in the following years.

About the study

The score has been developed by D’Amico et al. following a study on 1872 men treated for localized adenocarcinoma of the prostate between January 1989 and October 1997.

The majority (1654) have underwent radical prostatectomy (RP) while the rest (218) underwent implant with or without neoadjuvant androgen deprivation therapy.

The main outcome measure was actuarial freedom from PSA failure (defined as PSA outcome). The study defined the risk categories as follows:

■ Low-risk patients (stage T1c, T2a and PSA level ≤10 ng/mL and Gleason score ≤6);

■ Intermediate-risk patients (stage T2b or Gleason score of 7 or PSA level >10 and ≤20 ng/mL);

■ High-risk patients (stage T2c or PSA level >20 ng/mL or Gleason score ≥8).

Low-risk patients were found to have estimates of 5-year PSA outcome after treatment with RP, RT, or implant with or without neoadjuvant androgen deprivation.

Original source

D’Amico AV, Whittington R, Malkowicz S, et al. Biochemical Outcome After Radical Prostatectomy, External Beam Radiation Therapy, or Interstitial Radiation Therapy for Clinically Localized Prostate Cancer. JAMA. 1998; 280(11):969-974.

Validation

Boorjian SA, Karnes RJ, Rangel LJ, Bergstralh EJ, Blute ML. Mayo Clinic validation of the D’Amico risk group classification for predicting survival following radical prostatectomy. J Urol. 2008; 179(4):1354-60.

Other references

1. Hernandez DJ, Nielsen ME, Han M, Partin AW. Contemporary evaluation of the D’Amico risk classification of prostate cancer. Urology. 2007; 70(5):931-5.

2. Rodrigues G. et al. Pre-treatment risk stratification of prostate cancer patients: A critical review. Can Urol Assoc J. 2012; 6(2): 121–127.