MRI helps diagnose more clinically significant prostate cancers than PSA testing: Study
UK: The use of noncontrast MRI helps in finding more clinically significant prostate cancers as compared to prostate-specific antigen (PSA) testing, finds a recent study in the journal JAMA Oncology. Also, the bi-parametric MRI eliminated gadolinium exposure and shortens scan times.
The use of PSA testing for prostate cancer screening can lead to problems of overdiagnosis and underdiagnosis. These limitations can be conquered by the use of short, noncontrast magnetic resonance imaging (MRI).
David Eldred-Evans, Imperial College London, London, United Kingdom, and colleagues aimed to compare the performance of MRI, PSA testing, and ultrasonography as screening tests for prostate cancer.
For the purpose, the researchers conducted a prospective, population-based, blinded cohort study at 7 primary care practices and 2 imaging centers in the United Kingdom. Men aged 50 to 69 years of age were invited for prostate cancer screening from October 10, 2018, to May 15, 2019.
All participants underwent screening with a MRI (T2 weighted and diffusion), PSA test, and ultrasonography (B-mode and shear wave elastography). The interpretation of the tests were done independently of the knowledge of other results.
Both imaging tests were reported on a validated 5-point scale of suspicion. If any test result was positive, a systematic 12-core biopsy was performed. Additional image fusion–targeted biopsies were performed if the MRI or ultrasonography results were positive.
The researchers invited a total of 2034 men; of 411 who attended screening, 408 consented to receive all screening tests.
Key findings of the study include:
- The proportion with positive MRI results (score, 3-5) was higher than the proportion with positive PSA test results (72 [17.7%] vs 40 [9.9%]).
- The proportion with positive ultrasonography results (score, 3-5) was also higher than the proportion of those with positive PSA test results (96 [23.7%]).
- For an imaging threshold of score 4 to 5, the proportion with positive MRI results was similar to the proportion with positive PSA test results (43 [10.6%]), as was the proportion with positive ultrasonography results (52 [12.8%]).
- The PSA test (≥3 ng/mL) detected 7 clinically significant cancers, an MRI score of 3 to 5 detected 14 cancers, an MRI score of 4 to 5 detected 11 cancers, an ultrasonography score of 3 to 5 detected 9 cancer, and an ultrasonography score of 4 to 5 detected 4 cancers.
- Clinically insignificant cancers were diagnosed by PSA testing in 6 cases, by an MRI score of 3 to 5 in 7 cases, an MRI score of 4 to 5 in 5 cases, an ultrasonography score of 3 to 5 in 13 cases, and an ultrasonography score of 4 to 5 in 7 cases.
"Our results show that when screening the general population for prostate cancer, MRI using a score of 4 or 5 to define a positive test result compared with PSA alone at 3 ng/mL or higher was associated with more men diagnosed with clinically significant cancer, without an increase in the number of men advised to undergo biopsy or overdiagnosed with clinically insignificant cancer," wrote the authors.
"There was no evidence that ultrasonography would have better performance compared with PSA testing alone."
The study tilted, "Population-Based Prostate Cancer Screening With Magnetic Resonance Imaging or Ultrasonography: The IP1-PROSTAGRAM Study," is published in the journal JAMA Oncology.