MRI may reduce need for biopsy in prostate cancer

An MRI-based approach to prostate cancer screening could cut down on overdiagnosis of non-aggressive disease, according to findings presented at the European Association of Urology.

According to the National Cancer Institute, the latest age-adjusted data show there are 129.4 new cases of prostate cancer per 100,000 men per year and 20.7 deaths per 100,000 men per year in the United States.

Researchers from Erasmus Medical Centre in the Netherlands compared transrectal ultrasound-guided random prostate biopsy (TRUS-biopsy) and MRI-based screening among 335 heavily prescreened men. They took 6-core TRUS-biopsy samples from 177 men and 12-core TRUS-biopsy samples from 158 men; the latter group had first undergone an MRI. If the MRI showed a suspicious area, additional MRI-targeted biopsy samples were taken. The participants had a mean age of 73.2 years and a mean PSA of 5.1 ng/ml, and there were no significant differences in terms of age, PSA or previous biopsy status between the study groups.

They found that the 6-core TRUS-biopsy, 12-core TRUS biopsy and MRI-targeted biopsy methods all had a similar detection rate for more high-grade cancers; however, using the MRI-targeted biopsy method, 70% of the men did not need a biopsy at all as the MRI scan had shown no suspicious areas. In addition, the MRI-targeted biopsy-only approach meant that the number of men who were overdiagnosed with nonaggressive cancer was reduced by half.

“This could change the balance of the equation. It means that population-based prostate cancer screening with MRI instead of TRUS-biopsy has a significantly better risk/benefit ratio and could offer real benefits to men at risk of prostate cancer,” Arnout Alberts, MD, of the department of urology at Erasmus Medical Centre, said in a press release. Now [that] we have shown that MRI screening has potential, we need confirmatory studies in a true screening setting to allow us to get a better handle on the statistics and costs. MRI screening for prostate cancer will be more expensive than the currently used approach, but introducing mammography screening a generation ago was also expensive; we have to decide if it’s worthwhile.”

Jochen Walz, MD, chair of the European Association of Urology Section of Urological Imaging, expressed both optimism and caution about the use of MRI for prostate cancer screening.

“MRI indeed has great potential to improve prostate cancer diagnosis. Still, we need to note that prostate MRI is a challenging imaging technology with good results depending on the skills of dedicated and well-trained experts, which is another parallel shared with mammography,” Walz said in the release. “Before prostate MRI might be used in a general population for early detection or screening of prostate cancer, these issues need to be solved ... Moreover, the cost-effectiveness and the extensive need of health resources are another pending issue, needing further realistic analyses before the above approach can be recommended for routine use.” – by Janel Miller

References:

Alberts, A, et al. Abstract 501. Presented at: European Association of Urology Annual Meeting; March 24-28, 2017; London.

National Cancer Institute Cancer Stat Facts: Prostate Cancer (accessed 04-12-2017)

Disclosure: Healio Family Medicine was unable to confirm the researchers’ relevant financial disclosures prior to publication.