Population-based prostate cancer screening using a prospective, blinded, paired screen-positive comparison of PSA and fast MRI: The IP1-PROSTAGRAM study.

Abstract

5513 Background: The prostate-specific antigen (PSA) test can lead to under- and over-diagnosis of prostate cancer and has not been recommended for population screening. A fast MRI scan might overcome the limitations of PSA. IP1-PROSTAGRAM is the first study to evaluate the performance of a 15-minute non-contrast MRI for prostate cancer screening in comparison to PSA. Methods: IP1-PROSTAGRAM was a prospective, population-based, screen-positive paired-cohort study. Men aged 50-69 years in the UK were invited for prostate cancer screening through seven primary care practices or community-based recruitment. Participants underwent a PSA and MRI scan (T2-weighted and diffusion). MRI was scored using PIRADS version 2.0 without knowledge of PSA; screen-positive MRI (defined as either PIRADS score 3-5 or 4-5) were compared against a screen-positive PSA defined as ≥3ng/ml. If any test was screen-positive, a systematic 12-core biopsy was performed with MRI-ultrasound image-fusion targeted biopsy to MRI suspicious areas, as appropriate. Clinically-significant cancer was defined as any Gleason score ≥3+4. The primary outcome was the proportion of screen-positive MRI at different scores; important secondary outcomes were the number of clinically-significant and insignificant cancers detected. Results: 2034 men were invited to participate of whom 408 consented and 406 were screened by both PSA and MRI (10/Oct/2018-15/May/2019). The proportion with a screen-positive MRI (score 3-5) was higher than the proportion with a screen-positive PSA (17.7% [95%CI 14.3-21.8] vs. 9.9% [95%CI 7.3-13.2]; p < 0.001). A screen-positive MRI (score 4-5) was similar to a screen-positive PSA (10.6% [95%CI 7.9-14.0] vs. 9.9% [95%CI 7.3-13.2], p = 0.71). An MRI score 3-5 or 4-5 used to denote a screen-positive MRI, compared to PSA alone, detected 14, 11 and 7 clinically-significant cancers, respectively. There were 7, 5 and 6 clinically-insignificant cancers detected, respectively. No serious adverse events occurred. Conclusions: When screening the general population for prostate cancer, MRI using a score of 4-5 to define a screen-positive test, compared to PSA alone at ≥3ng/ml, could lead to more men diagnosed with clinically-significant cancer without increasing the number of men biopsied or diagnosed with clinically-insignificant cancer. Clinical trial information: NCT03702439 .

Oncologically Relevant Findings Reporting and Data System (ONCO-RADS): Guidelines for the Acquisition, Interpretation, and Reporting of Whole-Body MRI for Cancer Screening

“…This protocol can be considered analogous to the core protocols recommended for metastasis detection in advanced prostate cancer (Metastasis Reporting and Data System for Prostate Cancer) (23) and multiple myeloma (Myeloma Response Assessment and Diagnosis System) (24), with minor modifications, and can be completed within 30 minutes (Table 1, Fig 1). Optional detailed images of the prostate gland in older men using T2-weighted and high b-value DW images may be considered (25).…”

“…Similar limitations can occur for the detection of prostate cancers. With the whole-body MRI protocol, only larger cancers can be detected and focused prostate cancer studies are needed (25). In the absence of intravenous contrast material administration, which is considered mandatory only in patients with LFS, neurofibromatosis, constitutional mismatch repair deficiency syndrome, and hereditary retinoblastoma, it is not possible to confidently detect small brain lesions or small meningiomas with whole-body MRI.…”