Predictive algorithms and nomograms combine multiple variables to provide information that is statistically more significant than any individual variable. A nomogram is “an objective tool that uses an algorithm or mathematical formula to predict the probability of an outcome”. These tools can give probabilities of cancer location or of treatment success, based on scientific studies done with hundreds or thousands of patients. While these may provide some guidance, remember that they are not based on treatments using techniques as practiced today (such as IMRT). Algorithms/nomograms may be valuable for evaluating the potential extent of your disease and your risk of recurrence but they do not determine your outcome. You should discuss the results with your own physicians.
The information required is normally available on your medical records. You should get copies of them if you do not have them.
Many algorithms have been published in the peer-reviewed literature. The most familiar algorithm is derived from the work of Dr. Alan Partin et al from the Johns Hopkins Medical Center to predict extent of prostate cancer. It uses prostate-specific antigen level, clinical stage, and biopsy Gleason score. The most recent “Partin Tables”, based on cases from 2000 to 2005, are available from the Johns Hopkins website at: http://urology.jhu.edu/prostate/partintables.php
The University of California San Francisco developed the UCSF Cancer of the Prostate Risk Assessment (CAPRA) score, which is intended to combine the accuracy of nomograms with the ease of calculation of risk. See our November 2010 Insights article Understanding and Applying
Risk Assessment for Prostate Cancer.
The Johns Hopkins website also has the Han Tables which provide two models at: http://urology.jhu.edu/prostate/hanTables.php
1. Preoperative Prediction of recurrence probability following surgery using the available information BEFORE the surgery (PSA level, biopsy Gleason score, and clinical stage)
2. Postoperative Prediction of recurrence probability following surgery using the available information BEFORE AND AFTER the surgery (PSA level, surgical Gleason score, and pathological stage)
Additional nomograms can be found in our Nov. 2005 PCRI Insights issue. See Using Nomograms to Predict Pathological Stage and Treatment Outcome. The article describes eight different scenarios of situations often faced by prostate cancer patients:
PSADT should be based on at least three values separated by at least three months each. PSADT is best calculated with a mathematical log-slope method. You will find a good PSA Doubling time calculator and several other nomograms including:
- Pre-Treatment (Diagnosed But Not Yet Begun Treatment)
- Post-Radical Prostatectomy Recurrence
- Salvage Radiation Therapy
- Hormone Refractory (Progression of Metastatic PC after ADT)
- Predicting Cancer Risk Following Initial Biopsy
- Predicting Cancer Risk Following Repeated Biopsy
- Prediction Increased Pathologic Gleason Score
- Pre-Treatment – Prediction Indolent Cancer, Freedom from Recurrence, Metastasis, and Trifecta
- Post-Treatment – Predicting Freedom from Recurrence
- Predicting PSA Recurrence Following Salvage Radiation Therapy
- Hormone Refractory Metastatic Prostate Cancer – Predicting 1 and 2-Year Survival