What is the problem being addressed?
Of 50,000 newly diagnosed patients with prostate cancer every year, about 7,600 choose
active surveillance rather than immediate surgery or radiotherapy. Most have low risk
whilst 20-30% have medium risk prostate cancer. This is because low and medium risk
prostate cancers grow slowly. As a result, immediate treatment does not improve
cancer-specific survival over 10 years but can cause high rates of urinary, sexual and
bowel side-effects.
Although these cancers are slow growing, 25-34% will progress to higher risk over 5 years
and need treatment later. Whilst there is no evidence that delayed detection of
progression has an impact on survival, a recent systematic review has shown detrimental
effects on other aspects of cancer control. For instance, in the largest RCT comparing
active surveillance to immediate surgery or radiotherapy, 2-3 times as many patients had
disease progression and cancer spread to other parts of the body in the active
surveillance arm. So, active surveillance needs to be improved. NICE currently advise
that active surveillance should involve 3-6 monthly prostate specific antigen (PSA) blood
tests and rectal examinations. They advise an MRI and biopsy at 12 months. After one
year, 3-6 monthly PSA and rectal examinations are recommended and further biopsy if the
PSA starts to rise or if the rectal exam detects a prostate nodule.
This is problematic for 3 reasons:
First, PSA and rectal examination changes are inaccurate in detecting progression. As a
result, some centres do regular biopsies every 1-2 years; this is borne out by a 48
physician survey (Jan 2022). However, biopsies alone are also inaccurate as they are
ultrasound-guided; the operator can see the prostate but not areas suspicious for cancer
progression.
Second, biopsies have side-effects such as infection, bleeding and pain; when these
occur, patients are less likely to agree to further biopsies. Biopsies cost £488 and lead
to significant NHS resource use. Regular and repeat biopsies can also cause prostate
scarring making surgery more difficult if it is needed later.
Third, 10-43% of patients often decide to have treatment even if the cancer has not
progressed. This is because of anxiety about living with cancer, or because of the biopsy
and burden of tests. Some studies have shown other psychological impacts such as
sub-clinical depression, illness uncertainty and hopelessness.
The Investigators propose using regular MRI scans in active surveillance to detect
progression. The team led the pivotal UK studies which changed recommendations for MRI in
diagnosing prostate cancer. Subsequently, The Investigators and others have shown that
regular prostate MRI scans with targeted biopsies to areas of suspicion are accurate in
ruling-out and detecting progression. To change NHS practice, an RCT is needed to compare
regular MRI scans to current NICE defined standard of care in patients who choose active
surveillance following an MRI-directed biopsy at time of diagnosis.
The studies proposal was positively reviewed by the NCRI Prostate Proposal Guidance panel
(7/2/2022).
Why is this research important?
The regular use of MRI in active surveillance will lead to greater confidence in
active surveillance for patients with low and medium risk prostate cancer. This is
because such a strategy is likely to detect cancer progression earlier with fewer
invasive biopsies. In previous studies, 1 of 672 patients chose treatment during
surveillance due to anxiety.
An additional ~2000 patients with medium risk cancer could be managed with active
surveillance in future.
Fewer NHS resources for clinic follow-ups, PSA tests and biopsies.
Of 5 research priorities that NICE have identified for prostate cancer, two relate to
improving active surveillance. Similarly, the James Lind Alliance has 3 research
priorities to improve active surveillance.
Research Question P - In patients who are on active surveillance for low to medium risk
prostate cancer, I - is the use of regular MRI scans C - compared to current NICE defined
standard of care, O - better at detecting cancer progression with less cost to the NHS
(fewer PSA tests, biopsies and clinic visits)?
b) Aims and Objectives
Primary Objective
In patients on active surveillance for prostate cancer, to demonstrate that use of
regular MRI scans is better able to detect cancer progression over 5 years compared to
the current NICE defined strategy.
Difference between current and planned care pathways
Current (NICE defined active surveillance):
PSA 3 monthly in year 1 and then 6 monthly with rectal exam annually. MRI will be carried
out at 12 months (if not had one at diagnosis). A biopsy will be required if indicated
due to changes in rectal exam or PSA.
Planned (Regular MRI based active surveillance):
Patients with a visible lesion or medium risk cancer will have PSA 6 monthly and MRI
annually. All other patients will undergo PSA 6 monthly and MRI in years 1, 3 and 5. In
all patients, a targeted biopsy will be carried out if the MRI PRECISE score is >/=4.