Prostate Cancer Risk Calculator

How does this prostate cancer risk calculator work?

This is a health tool based on the UCSF-CAPRA score with statistical data from the Cancer of the Prostate Strategic Urologic Research Endeavor (CaPSURE) that is used to make the risk assessment of prostate cancer patients.

It is a formula tested on over 10k patients being treated for prostate cancer facilitates disease risk classification and helps specialist decision making and comes as an improvement that tries to address the limitations of other risk assessment tools such as the D’Amico classification.

There are five indicators, as described below, that are being taken in consideration in the CAPRA score and each of them has answer choices that are awarded points.

Once all criteria are met, this prostate cancer risk calculator will reveal the result with the score and a short description regarding the metastasis likelihood in 5 years.

■ Age at diagnosis – patients under 50 or above. Prostate cancer affects mainly patients over 50 and risk increases with age. The average diagnosis age being around 72 years.

■ Gleason score – this is the score of the biopsy (primary or secondary) and has as choices: no pattern 4 or 5; secondary pattern 4 or 5 and primary pattern 4 or 5. The Gleason grading system is used by pathologists in the biopsy examination and is based on the architectural pattern on the glands in the prostate tumor and which is the degree of resemblance to the normal cells.

■ PSA in ng/mL – this is the value measured at diagnosis and is either under or equal to 6; between 6.1 - 10; between 10.1 -20; between 20.1 – 30 and above 30. This is the prostate specific antigen, a protein of the prostate cells that can be found in blood. Raised PSA levels are a sign of prostate cancer but this is not used as sole diagnosis because there are many men with raised levels of PSA and no cancer but also cases of prostate cancer with normal PSA.

■ Clinical stage – this refers to the T stage, either T1 or T2 or T3a. Clinical stages are an indicator of how big and spread the prostate cancer is and the TNM system is used in this case.

- T1 tumors are small and can only be discovered through biopsy.

- T2 tumors are divided in T2a, T2b and T2c depending on the localization inside the gland and the spread. T3 tumors are spread through the capsule of the gland (T3a) and even into the seminal vesicles (T3b).

- T4 tumors are spread to nearby organs.

■ Cancer positive biopsy cores percent (PBCP) – this is to be chose between below 34% and 34% or above. This is a good indicator of tumor stage and volume at radical prostatectomy and a predictor of clinical outcome in radiotherapy treated cancers.

Example result

Let’s take the case of a patient aged 56, with a Gleason score secondary pattern 4 or 5, PSA value at diagnosis between 10.1 and 20, clinical stage T2 and Cancer positive biopsy cores percent below 34%.

CAPRA Score is 4. This score result indicates an intermediate risk prostate cancer.  Intermediate risk tumors respond to localized surgery or radiation. According to the UCSF – CAPRA research, likelihood of metastasis in these case within 5 years is 1% while detectable PSA or necessity of second oncologic treatment within 5 years occurred in 18% of cases.

References

1) Matthew R. Cooperberg, MD, MPH, David J. Pasta, MS, Eric P. Elkin, MPH, Mark S. Litwin, MD, MPH, David M. Latini, PhD, Janeen DuChane, PhD, and Peter R. Carroll, MD† The UCSF Cancer of the Prostate Risk Assessment (CAPRA) Score: a straightforward and reliable preoperative predictor of disease recurrence after radical prostatectomy. J Urol. 2005 Jun; 173(6): 1938–1942.

2) Cooperberg, M.R., J.M. Broering, and P.R. Carroll, Risk assessment for prostate cancer metastasis and mortality at the time of diagnosis. J Natl Cancer Inst, 2009. 101(12): p. 878-87.