Revamped Prostate Cancer Risk Calculator Now Online

Fran Lowry

August 08, 2014

The first version of the Prostate Cancer Risk Calculator, developed in 2006 to help men and their doctors assess their risk for prostate cancer, has been completely revamped.

Version 2.0 uses current risk factors and gives a more nuanced result to help a man and his physician understand the risk for prostate cancer. A report on the rationale for the update was published online August 4 in JAMA.

The free calculator, available online, uses patient-reported risk factors to predict the chances for no, low-grade, and high-grade prostate cancer. It then produces a graphic display of the numeric percentage for each possibility using a grid of 100 emojis.

Green smiley faces indicate a negative biopsy result, yellow faces with a neutral expression indicate a slow-growing cancer that probably does not require treatment, and red frowning faces indicate aggressive cancer that requires aggressive treatment. Obviously, the more green smiley faces, the better.

Population and Risk Factors Have Changes

"The population has changed. The risk factors have changed," said Ian M. Thompson Jr., MD, director of the Cancer Therapy and Research Center at the University of Texas Health Science Center in San Antonio, who was instrumental in developing the first version of the calculator.

"The general population's risk is different today than when the risk-assessment tool was created, probably for the same reasons the risk of the general population is different with regard to things like cholesterol," he told Medscape Medical News.

Sample of the risk calculator results.

Although the original version of the calculator performed well in general, it was not as precise as it could be. The update uses contemporary data to generate results, Dr. Thompson noted.

"Version 1.0 provided 2 numbers — indicating risk of cancer upon biopsy and risk of aggressive cancer. It's important to understand that what we are looking for is not necessarily cancer, but consequential cancer. We found that version 1.0 did not provide as sophisticated an explanation for patients," he explained.

The updated calculator asks a man's age, race or ethnicity, family history of prostate cancer, results from previous prostate cancer examinations, and results from previous prostate biopsies.

Dr. Thompson describes the updated calculator in detail in a video posted online.

"Being able to predict a man's chances of having a negative biopsy is really important, because the risk of infection from a biopsy is 2% to 4%. If the biopsy is negative, it was unnecessary. For all of us who take care of patients, the worst thing that can happen is that a patient gets sick from the biopsy," Dr. Thompson said.

The risk calculator is based on data from the 18,882-man Prostate Cancer Prevention Trial, which was led by Dr. Thompson (J Natl Cancer Inst. 2006;98:529-534).

"At the end of that study, we recommended a biopsy in all of the men, regardless of their PSA [prostate-specific antigen]. It was the first study to biopsy men with PSAs less than 4. This led to 2 papers in the New England Journal of Medicine that showed that, actually, most prostate cancers are in men with PSAs less than 4," he said.

The US Preventive Services Task Force has recommended against PSA screening in the general population. Dr. Thompson said he thinks there is some validity to that recommendation, but disagrees with its one-size-fits-all approach.

"Unfortunately, they have to boil the recommendation down to a single statement. It's like telling people what the best car for them to buy is. But PSA testing is extremely nuanced, and different patients will have different priorities, risks, and medical conditions. If you give the same set of information to 2 different patients, they will come to different conclusions about what they want to do," he said.

"My personal preference is to inform the men and then allow them to make an intelligent decision. One man will opt for PSA testing, another will say no; that's the right way," Dr. Thompson explained. "But to have one organization be the surrogate and to set the priorities for all the men in the United States — I'm not so sure that is the way to go."

The calculator will probably be updated again as population patterns change, Dr. Thompson said.

"This is a work in progress. There are other things that probably should be involved in the decision-making process. I imagine that version 3.0 might include an assessment of the patient's overall health and life expectancy, as well as current sexual and urinary function," he noted.

The calculator can also be used by the primary care physician, Dr. Thompson said.

"It helps you have an intelligent conversation with a patient. It takes it away from 'I think you have cancer, we should do a biopsy,' to making the decision more personalized and individualized," he said.

This work was supported by the National Cancer Institute. Dr. Thompson has disclosed no relevant financial relationships.

JAMA. Published online August 4, 2014. Abstract


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