Imaging in prostate cancer patients often used inappropriately

May 1, 2011

A substantial proportion of patients over age 65 years with newly diagnosed prostate cancer are not being treated according to existing guidelines for imaging in this setting.

Orlando, FL-A substantial proportion of patients over age 65 years with newly diagnosed prostate cancer are not being treated according to existing guidelines for imaging in this setting, according to a retrospective review presented at the Genitourinary Cancers Symposium in Orlando, FL.

Both overutilization of imaging where it is not needed and underutilization of imaging where it should be used account for this discrepancy, say researchers from the University of Chicago Medical Center and Brigham and Women's Hospital, Boston.

"Despite the existing guidelines of the AUA and the National Comprehensive Cancer Network [NCCN], 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 first author Sandip M. Prasad, MD, a Society of Urologic Oncology fellow at the University of Chicago Medical Center.

Both the AUA and NCCN guidelines recommend radiographic imaging only for high-risk patients. The retrospective study was based on a sample from the Surveillance, Epidemiology, and End Results-Medicare database of 30,183 men with prostate cancer diagnosed between 2004 and 2005. A total of 9,640 men were diagnosed with low-risk prostate cancer, 12,966 were diagnosed with intermediate-risk prostate cancer, and 7,577 men were diagnosed with high-risk disease. Of these, 36% of low-risk patients, 49% of intermediate-risk patients, and 61% of high-risk patients underwent imaging after diagnosis.

Factors associated with overutilization of imaging included older age, African-American ethnicity, higher income level, and living in rural areas, while appropriate use of imaging was highest in educated men.

Many unnecessary, costly tests performed

"We found that unnecessary and expensive imaging procedures were performed in 36% of low-risk patients and 49% of intermediate-risk patients, while 39% of high-risk patients were not getting recommended imaging for adequate staging prior to treatment. These percentages should be closer to 0%, 0%, and 100%, respectively," Dr. Prasad said.

The cost of unnecessary imaging was an estimated $35 million, which is more than 10% of the annual prostate cancer research budget of the National Cancer Institute, he noted.

The most frequently ordered type of imaging test among all three risk groups was a bone scan to determine the presence or absence of metastases. Dr. Prasad speculated that overutilization of imaging may be related to defensive medicine, reimbursement, or to patient desire for a complete metastatic workup, even in the setting of low-risk disease when prostate cancer metastases are uncommon.

Although the cost of unnecessary imaging is important and has implications for health care reform, Dr. Prasad was equally concerned that almost 40% of high-risk men were not being treated according to national guidelines and did not receive adequate staging prior to treatment.

"This may result in men with high-risk prostate cancer with undetected metastases receiving ineffective local therapy without benefit," he said.