Researchers have developed a personalized tool that helps to predict which men face a high risk of being overdiagnosed with prostate cancer. Up to 42% of men are overdiagnosed with the disease, leading to unnecessary treatment and serious side effects.

To address that problem, researchers from the Fred Hutchinson Cancer Research Center and the University of Washington in Seattle have developed a nomogram, a graphical calculating device that incorporates a patient’s age, prostate-specific antigen level, and Gleason score to determine the likelihood that a screening-detected prostate cancer has been overdiagnosed. Investigators intend for the tool to be a guide in better determining personalized treatment options.

To develop the nomogram, the researchers created a virtual population model of US men aged 50 to 84 years from 1975 to 2005. They applied existing data regarding prostate-specific antigen levels, biopsy practices, and cancer diagnosis patterns to learn about cancer progression in patients with and without screening. Next, they overlaid screening and biopsy patterns on the model to determine when the men would have been diagnosed with and without screening and which ones would have died of other causes. The data enabled the researchers to develop a prediction model that estimates the likelihood of overdiagnosis on a scale of 2.9 to 88.1.

Although nomograms are common in prostate cancer research, the authors say that to their knowledge theirs is the first to examine the likelihood of prostate cancer overdiagnosis on an individual level. They plan to develop an interface and test the nomogram in a pilot study tentatively planned for later this year.