New research found that active surveillance using MRI for prostate cancer is more cost-effective when compared to active surveillance with repeat biopsies and prostate-specific antigen (PSA) tests alone because MRI reduces the number of biopsies needed while also increasing the likelihood of finding a clinically significant cancer. The study also determined men with low-risk prostate cancer who incorporate MRI during active surveillance had a higher life expectancy, and preserved quality of life.
The National Cancer Institute estimates that 248,000 men will be diagnosed with prostate cancer in 2021, most in its earliest stages. For these men, a treatment strategy known as active surveillance, an approach that closely monitors the growth and development of the cancer, usually with repeated PSA blood tests and repeat biopsies, is often recommended. Additionally, in the last decade, the use of magnetic resonance imaging, or MRI, for prostate cancer has grown in popularity within the medical community because MRI allows clinicians to identify and target the biopsy to the area of the gland that harbors the clinically significant cancer.
Published in the journal Radiology online July 13, researchers and clinicians at NYU Grossman School of Medicine created a mathematical model to simulate the cost-effectiveness of various surveillance strategies for men with low-risk prostate cancer. The strategies compared in the simulation included the following:
- watchful waiting (conservative approach without required surveillance, where treatment is given for symptomatic progression)
- active surveillance with PSA and repeat annual biopsy regardless of PSA results
- active surveillance with PSA to determine if MRI and biopsy are needed
- active surveillance with PSA testing and MRI, using different thresholds of the MRI score called PIRADS to determine whether biopsy is needed
The simulations revealed that men with all strategies of active surveillance incorporating an MRI had improved quality of life and life expectancy compared to those without MRI. Additionally, results suggest an ideal frequency of repeat biopsy with MRI, guidance currently not available in the field.
“Globally, the use of prostate MRI during active surveillance is increasing, and yet there are no consistent guidelines about its impact on clinical care, and how exactly clinicians can use the test during active surveillance,” says lead author, Stella K. Kang, MD, associate professor in the Departments of Radiology and Population Health and director of comparative effectiveness and outcomes research within the Department of Radiology at NYU Langone. “Our research shows that that MRI is a cost-effective tool for men and their clinicians to use to guide their management.”
For the current comparative effectiveness and economic evaluation, researchers constructed a decision tree outlining multiple different MRI and biopsy strategies, incorporating the costs and impact on quality of life associated with each health event. It also enabled tracking of individual hypothetical patients to increase representation of individual differences in disease course and to summarize outcomes.
As a cost-effectiveness analysis, the average 60-year-old man in the simulation had an extended quality-adjusted life years (QALY) and life expectancy with all active surveillance strategies incorporating MRI. Individuals who had active surveillance strategies with annual MRI yielded the highest QALY of 16.19, compared to active surveillance with no MRI (16.14 QALY) and watchful waiting (15.94 QALY). The strategy with the highest economic value was an annual MRI using a PI-RADS score of at least 4 out of 5 to do a biopsy, instead of PI-RADS of at least 3, because it lowered the number of biopsies over a lifetime. A PI-RADS score of at least 4, indicating that a clinically significant cancer is likely to be present, led to 42 percent fewer biopsies over the patient’s lifetime.
Researchers say the results should empower men to consider all options available to them and work with their care team to determine the best management approach. Men can decide with their doctor what is the optimal approach to monitor the disease while also preserving quality of life. Predictive simulation like this will ultimately allow men to experience fewer unnecessary biopsies.
“These findings are very important, especially given the high prevalence of prostate cancer and expanding use of active surveillance,” says Stacy Loeb, MD, MSc, professor in the Departments of Urology and Population Health at NYU Langone Health, and the study senior author. “There is currently no consensus over the optimal monitoring protocol during active surveillance. These results suggest that MRI can help to reduce the total number of serial biopsies, while preserving quality of life. These results can help patients and physicians to explore the trade-offs involved in different monitoring approaches.”
The models used in this simulation are a form of evidence synthesis, and researchers applied data from published clinical trials and studies on prostate MRI performance. Researchers caution that the simulation does not account for real-life experiences for all patients, such as age, comorbid health conditions, and misclassification of cancer, and that further research is needed.
Funding support for the study was provided by the Prostate Cancer Foundation and National Institutes of Health.
In addition to Dr. Kang and Dr. Loeb, other investigators involved in the study were Vinay Prabhu, MD, MS, from NYU Langone and Rahul Mali, MD, MPH, and Bart Ferket, MD, PhD, at Mount Sinai in New York.