Imaging for Prostate Cancer Does Not Adhere to National Guidelines

According to a retrospective review of a SEER-Medicare database presented at the ASCO Genitourinary Cancers Symposium (abstract 120), doctors in the United States who treat Medicare patients are not following existing guidelines for the imaging of newly diagnosed prostate cancer, The American Urological Association (AUA) guidelines recommend pretreatment staging of prostate cancer only in the setting of highrisk disease, whereas the National Comprehensive Cancer Network (NCCN) recommends radiographic imaging only in the setting of high-risk pathology features. Yet the study showed that about one-third of men with low- and intermediate-risk prostate cancer undergo unnecessary tests, while almost 40% of high-risk men are not undergoing recommended imaging studies for adequate staging prior to treatment.

“Despite the existing guidelines of the AUA and the National Comprehensive Cancer Network, costly and unnecessary imaging studies continue to be performed, while a significant number of men with high-risk disease do not receive adequate staging prior to treatment,” said lead author Sandip M. Prasad, MD, of the University of Chicago Medical Center.

The study was undertaken to characterize current utilization patterns for diagnostic imaging with CT scans, MRI scans, and bone scans and determine if imaging was in line with existing guidelines. Also, the authors wanted to estimate the cost of overutilization of imaging in situations in which it is not recommended. The database included 30,183 men; 9640 were diagnosed with low-risk prostate cancer; 12,966 were diagnosed with intermediate-risk prostate cancer; and 7577 were diagnosed with high-risk prostate cancer.

Following their diagnosis of prostate cancer, 36% of low-risk men, 49% of intermediate-risk men, and 61% of high-risk men underwent radiographic imaging. “These percentages should have been 0%, 0%, and 100%, respectively,” he stated. “These figures are cause for concern.”

“Unnecessary testing among the 30,000-plus men in the SEER-Medicare database led to an estimated expenditure of $35 million,” Prasad said. He noted that this is more than 10% of the annual prostate cancer research budget of the National Cancer Institute.

The overuse of imaging was associated with older age, black ethnicity, higher economic level, and living in rural areas, whereas the use of imaging according to the guidelines was highest in educated men. While the costly and unnecessary overuse of imaging in low- and intermediate-risk patients causes concern, even more disturbing to Prasad is the fact that 39% of the high-risk men were not getting imaging according to existing guidelines.

In a separate interview, Prasad speculated that the overuse of imaging was related to “defensive” medicine, to ensure that doctors were covering all bases before deciding on a course of treatment. The most frequently ordered type of imaging test among all 3 risk groups was a bone scan to look for metastases.