MRI Prostate for Chinese Men Being Screened for Prostate Cancer
MRI Prostate for Chinese Men Being Screened for Prostate Cancer
Under the prostate cancer screening protocol of the project 'Prevention of Obesity-related
 Cancers', men with elevated PSA with higher prostate cancer risk (PSA 4-10 ng/mL with high
 Prostate Health Index (PHI) ≥35, or PSA>10 ng/mL) will be offered a prostate biopsy.

 In the current study, we would like to offer all screened men with elevated PSA in the range
 of 4-50 ng/mL a biparametric non-contrast MRI prostate (screening protocol) for any
 suspicious lesion in the prostate. If there is MRI lesion seen, additional targeted biopsies
 can be performed on top of the standard systematic prostate biopsies. It has been shown in a
 clinical Caucasian cohort that doing MRI-targeted biopsies resulted in improved detection of
 clinically significant prostate cancer compared with standard systematic biopsies.

 In this study investigators would like to investigate the benefits of adding MRI prostate and
 MRI-targeted biopsy in the diagnostic pathway for prostate cancer in a screened cohort of
 Chinese men at risk of prostate cancer.
Prostate cancer (PCa) is the second most common cancer in the world, and its incidence in the
 Asia-Pacific region is increasing. While serum prostate specific antigen (PSA) level remains
 the commonest marker for screening of the disease, its specificity is very low. As a result,
 many patients with elevated PSA are subjected to transrectal ultrasound guided prostatic
 biopsy (TRUSPB) with negative result, but at the same time faced the complications of
 bleeding and infection from TRUSPB. Performing a standard 10-12 core systematic prostate
 biopsy in all men with elevated PSA was shown to miss some clinically significant prostate
 cancers while over-diagnosing some insignificant prostate cancers. In the European randomized
 study of screening for prostate cancer (ERSPC), PSA-based screening have resulted in reduced
 prostate cancer-specific death and metastasis, but there were problems like over-biopsy and
 over-diagnosis of indolent prostate cancers. The number needed to screen (NNS) to prevent one
 prostate cancer death was quite high at 781. Therefore, population-wide screening of men with
 PSA is not commonly applied in most places.

 The blood test Prostate Health Index (PHI) provides much better prostate cancer risk
 stratification than PSA by dividing men with PSA 4-10 ng/mL. Using PHI 35 as a cutoff,
 clinically significant prostate cancer (any Gleason pattern ≥ 4) was found in only 0.7% in
 PHI<35, but up to 8.6% in PHI ≥35, a 12 fold difference. The use of PHI test could
 significantly reduce unnecessary prostate biopsies and was approved by FDA in 2012. Since
 2016, the PHI blood test was available in the public health system in Hong Kong for men with
 PSA 4-10 ng/mL. According to local audit on 2795 men receiving PHI test, about 80% prostate
 biopsies was avoided. This also resulted in a higher positive biopsy rate (from 10.7% to
 26.2%), with the potential of delayed diagnosis in only a minimal proportion of men (0.7%).
 Currently, PHI is being ordered regularly by Urologists in the public system of Hong Kong for
 men with PSA 4-10 ng/mL.

 In a landmark study by Ahmed et al in 2017, performing multi-parametric MRI prostate before
 an initial prostate biopsy in a clinical Caucasian cohort has been shown to improve diagnosis
 of significant prostate cancer by 18%, while reduce diagnosis of insignificant prostate
 cancer by 5%.

 Another Caucasian study by Alberts et al in 2017 in men who undergone the 5th round of
 screening in European Randomized Study of Screening for Prostate cancer Rotterdam, adding MRI
 prostate could avoid 65% biopsies and 68% insignificant prostate cancer, while detecting an
 equal percentage of significant cancers. The role of MRI in an Asian cohort under a screening
 protocol has not been reported before.

 Prostate cancer incidence in Asian is only about one-third of that in Caucasian, and cancer
 detection rates in different PSA ranges are also 50% less. Reported Caucasian prostate cancer
 detection rates was 25-50% in men with PSA 4-10 ng/mL and >50% in men with PSA 10-20 ng/mL.
 In Hong Kong Chinese men, only 15% men with PSA 4-10 ng/mL and 20-30% men with PSA 10-20
 ng/mL has prostate cancer. Therefore, screening tools like PHI or MRI are potentially more
 useful in reducing unnecessary biopsies in Chinese men even in higher PSA ranges (e.g. PSA >
 10 ng/mL) due to much lower cancer detection rate.

 A multiparametric MRI prostate combines T2-weighted (T2W), Diffusion-weighted imaging (DWI),
 and Dynamic contrast enhanced (DCE) sequences to aid identification of suspicious malignant
 lesions in the prostate using a standardized Prostate Imaging - Reporting and Data System
 (PI-RADS).

 In a recently published meta-analysis, it is suggested that a bi-parametric (using only T2W
 and DWI sequences without contrast) MRI prostate has similar performance compared with a
 multi-parametric MRI prostate. Omitting the DCE and contrast injection reduces scanning time
 by 30-50% (down to 15-20 minutes per patient) and avoids risk of gadolinium contrast,
 especially in men with impaired renal function.

 Under the prostate cancer screening protocol of the project 'Prevention of Obesity-related
 Cancers', men with elevated PSA with higher prostate cancer risk (PSA 4-10 ng/mL with high
 Prostate Health Index (PHI) ≥35, or PSA>10 ng/mL) will be offered a prostate biopsy.

 In the current study, investigators would like to offer all screened men with elevated PSA in
 the range of 4-50 ng/mL a biparametric non-contrast MRI prostate (screening protocol) for any
 suspicious lesion in the prostate. If there is MRI lesion seen, additional targeted biopsies
 can be performed on top of the standard systematic prostate biopsies. It has been shown in a
 clinical Caucasian cohort that doing MRI-targeted biopsies resulted in improved detection of
 clinically significant prostate cancer compared with standard systematic biopsies.

 In this study investigators would like to investigate the benefits of adding MRI prostate and
 MRI-targeted biopsy in the diagnostic pathway for prostate cancer in a screened cohort of
 Chinese men at risk of prostate cancer.
Inclusion Criteria:

 1. Men being screened for prostate cancer in the project 'Prevention of Obesity-related
 Cancers'

 2. Age 50-75

 3. Screening naïve, defined as no blood taking for PSA within past 5 years AND no
 prostate biopsy within past 5 years

 4. PSA 4-50 ng/mL

 5. Agree for non-contrast MRI scanning of prostate

 Exclusion Criteria:

 1. Men who are contraindicated for MRI( Pacemaker in-situ, Metallic implants which are
 not MRI-compatible, or Claustrophobia)

 2. Prior history of prostate cancer