A new study published in the August 2016 journal of Molecular and Clinical Oncology found that magnetic resonance imaging – ultrasound (MRI-US) fusion prostate biopsy outperforms traditional transrectal ultrasound (TRUS) –guided biopsy in detecting and diagnosing prostate cancer.
Prostate cancer is the second most commonly diagnosed cancer in men. Screening for prostate cancer relies mostly on a digital rectal exam or obtaining a blood sample to test a man’s prostate-specific antigen, or PSA which is a protein produced by cells of the prostate gland. If there is suspicion from findings of the digital rectal exam or PSA, the current standard for diagnosing prostate cancer in men at risk relies on the TRUS-guided biopsy test.
“The problem of using TRUS biopsy is that it only samples the lower portion of the prostate representing only about 1% of the prostate tissue when searching for prostate cancer. It uses a needle to collect twelve random samples within twelve cores of the prostate,” said Dr. David Samadi. “However, almost 30% of cancers are found outside of this area. This means that even if the biopsy is negative for finding cancer, there is still the possibility that the TRUS biopsy may have missed pockets of undetected disease.”
For this current study, a total of 3,415 cases from 21 studies were included in this meta-analysis with data expressed as relative risk (RR) and 95% confidence interval. Results showed that MRI-US fusion biopsy was able to detect more clinically significant cancers compared to TRUS guided biopsy. The overall prostate cancer detection rate of MRI-US fusion biopsy was found to be higher compared to TRUS guided biopsy with a RR of 1.09. MRI-US fusion biopsy also had a 22% increased detection rate for clinically significant prostate cancer compared with TRUS guided biopsy.
The findings raise concerns on using TRUS guided biopsy for a definitive and more accurate diagnosis. One is that TRUS guided biopsy may not be able to detect all cases of clinically significant prostate cancer which could delay a man getting the treatment he needs. The study also showed that MRI-US guided biopsy had better performance of avoiding detection of insignificant prostate cancer helping reduce oversampling of potentially insignificant tumors. MRI-US guided fusion biopsy also required fewer cores for successful tumor sampling, thus reducing patient discomfort compared with TRUS guided biopsy.
“The advantage of using MRI-US guided fusion biopsy is that it can fuse together real-time ultrasound images of the prostate allowing a more accurate and precise identification of suspicious lesions which may not have been found using traditional transrectal ultrasound,” stated Dr. Samadi. “Using MRI-US guided fusion biopsy has a 30-40% better chance of finding cancer than just using TRUS guided biopsy. It only takes about 15 minutes and can be done in the office.”
The MRI-US guided fusion biopsy also plays a valuable role in evaluating low risk patients with active surveillance and it can identify more aggressive cancers needing to be removed quickly in order to spare a patient’s quality of life and prevent metastasis.
Patients newly diagnosed with prostate cancer can contact world renowned prostate cancer surgeon and urologic oncologist, Dr. David Samadi, for a free phone consultation and to learn more about prostate cancer risk, call 212-365-5000.Health articles