Risk Assessment for Prostate Cancer
With the widespread use of prostate-specific antigen (PSA) testing to identify men at increased risk of prostate cancer, more individuals have been diagnosed with prostate cancer than in the period before PSA testing was widely available (pre-1992). Cancers diagnosed through PSA testing are often early stage or less advanced cancers. According to data from the National Cancer Institute, more than 90 percent of all prostate cancers are now diagnosed at a less advanced stage and men are surviving longer after diagnosis and treatment.
Once prostate cancer is diagnosed, you and your doctor must go through a process of risk assessment, estimating the likelihood that your cancer has or may spread outside the prostate and assessing your risk of disease recurrence after treatment. This assessment combined with characteristics of your overall health will allow your doctor to advise which treatment option will benefit you the most. Your doctor will use factors such as your Gleason score, PSA level, tumor stage and the number of tumor samples (called cores) taken by biopsy that are positive for cancer.
A variety of factors and tools can be used to assess your chances of surviving prostate cancer and the effectiveness of treatment in halting the progression of the disease. Among the tools your doctor may use are Internet-based calculators or nomograms, published tables and biological markers that may help predict outcomes.
Calculators or Nomograms
Online prostate cancer calculators, also called nomograms, provide forecasts of prostate cancer outcomes by calculating the statistical probability of disease progression or patient survival after treatment by comparing your individual information to data from many hundreds or thousands of other prostate cancer patients. Two particularly comprehensive calculators are available on Web sites from Memorial Sloan Kettering Cancer Center in New York (www.nomograms.org) and Temple University's Fox Chase Cancer Center in Philadelphia (www.fccc.edu).
The advantage of these predictive tools is that they are individualized to your particular condition and characteristics. The calculators ask you to respond to questions about your PSA level, age, tumor stage, Gleason score, biopsy cores and planned treatment or other information. Calculators are available to help you and your physician make treatment decisions before and after initial treatment and after a relapse.
However, as more men are diagnosed with lower-risk disease, these nomograms are proving less useful. For those men with newly diagnosed prostate cancer the great majority will be assessed as low or intermediate risk. These nomograms provide limited information to distinguish those men whose cancers will be cured from those in whom treatment will fail. In men with low or intermediate risk disease, new approaches and technologies involving biological markers are being developed to improve your doctor’s ability to estimate the curability of the cancer (see Biological Markers below).
You should talk with your physician or medical team to help you interpret the results of these calculators and make decisions about any planned treatment. The statistics you receive by filling out these nomograms will help you have an informed discussion with your doctor.
Created in 1997 and updated in 2001, Partin tables are published tables developed by urologists at the Brady Institute for Urology at Johns Hopkins University in Baltimore. Named for the lead authors of this research, the Partin tables are based on data from patients treated at three major prostate cancer research institutions: Johns Hopkins, Baylor College of Medicine in Houston and the Michigan Prostate Institute at the University of Michigan in Ann Arbor.
Like the online calculators, the Partin tables combine data on PSA levels, Gleason score and tumor stage to predict specific treatment outcomes for an individual patient. Physicians can use the tables to calculate probability estimates of four different risk factors that are important in making treatment decisions:
that your cancer is completely confined to the prostate;
that you have capsular penetration, meaning that your prostate cancer has extended into and possibly through the capsule (hard outer covering) of the prostate;
that your cancer has extended into the seminal vesicles (glands behind the prostate);
that your prostate cancer has spread to the lymph nodes.
It’s important to understand that the value of these tables in predicting outcomes has never actually been proved, and you should discuss the value of these tables with your physician.
PSA is a widely used biological marker, or biomarker, of prostate cancer risk. A lot of research is currently being done to identify other biomarkers of risk that may enhance the predictive value of nomograms and improve a physician’s ability to predict capsular penetration and distant metastasis (spread) of prostate cancer as well as cancer recurrence after treatment.
New approaches to risk assessment for prostate cancer are also emerging that combine biomarker testing, biopsy tissue analysis and clinical data to provide personalized risk assessments that could improve the accuracy of predicting patient outcomes from cancer treatments.