Big 4 - Prostate Cancer Flashcards
What is the lifetime risk for developing prostate cancer?
Who is at a greater risk?
- lifetime risk is 1 in 8
- men over 50 are more likely to develop prostate cancer
- risk is increased by 2.5x if there is FHx of a first-degree relative
- risk is greater if Afro-Caribbean descent
When might a PSA test be performed?
Is it offered for screening?
- it is NOT offered for screening as the benefits do not outweigh the risks
- men > 50 can request a PSA test if symptomatic, but should also be given written information
an informed discussion must take place first
What are the typical symptoms that prostate cancer presents with?
Urinary symptoms:
- reduced flow
- increased frequency
- nocturia
Symptoms of metastatic cancer:
- anaemia
- bone pain
- weight loss
- general malaise
What else might be causing the urinary symptoms?
benign prostatic hypertrophy (BPH)
further investigations can help identify prostate cancer
Why is PSA screening not performed?
- mortality from prostate cancer has been gradually decreasing
- when PSA screening was introduced, there was a spike in the cases being diagnosed
- PSA tests are identifying men with prostate cancer who would never have had symptoms / needed treatment
- this causes unnecessary anxiety
What is the normal value for PSA?
What is this and when might it be raised?
- the cut-off for further investigations is >3 ng/ml
- PSA is not specific to prostate cancer and may be raised in BPH and infection
Approximately what % of individuals with an abnormal PSA test will actually have prostate cancer?
- if 100 patients are tested, 17 will come back as abnormal
- these individuals will have further tests, including DRE, MRI and biopsy
- 13/17 (75%) of these patients will NOT have prostate cancer and the tests had been unnecessary
If someone >50 requests a PSA test and it comes back abnormal, what is the next stage?
- 2 week-wait referral to urology clinic
- referral for a pre-biospy MRI scan
- this is followed by a trans-rectal US biopsy
How is a trans-rectal US biopsy performed?
What are the risks associated with this?
- it is performed as an outpatient procedure, but risks include:
- rectal discomfort for a few days / weeks
- blood in the urine / semen
- urine infection with 3% risk of sepsis requiring hospitalisation
What is an alternative to transrectal US biopsy?
- trans-perineal biopsy
- this used to be avoided as it required GA, but can now be performed with LA
- there is a lesser risk of infection / sepsis
What happens if diagnosed prostate cancer is already metastatic?
the patient immediately begins systemic treatments
What happens if newly diagnosed prostate cancer is localised?
the cancer is graded according to the risk of recurrence & metastasis
this is done using the TNM staging, Gleason score and PSA value
What is the treatment plan for low risk prostate cancer?
- active surveillance
- radiotherapy
- surgery
active surveillance involves 3-4 monthly PSA tests, annual DREs and regular check-ups to avoid radical treatments for as long as possible
What is the treatment plan for intermediate or high risk prostate cancer?
- bone scan is performed to check for mets
- patient is then offered surgery or radiotherapy
- this can be external beam radiotherapy (EBRT) or internal radiotherapy (brachytherapy)
What is the Gleason score?
a histopathological score given to the prostatic biopsy based on how abnormal the tissue appears
How is the Gleason score calculated?
- the most prevalent abnormal tissue architecture within the sample is given a score from 1 to 5
- the second most prevalent abnormal tissue is also given a score
- the 2 scores are added together to give the Gleason score
Gleason score is being replaced by the ISUP grade
How is prostate cancer staged?
MRI scan and DRE are performed to calculate the TNM stage
What is involved in the T stage of the TNM staging?
T1 - no palpable or visible cancer (on biopsy only)
T2 - cancer within prostate gland only
T3 - cancer breaching prostate capsule
T4 - cancer invading into rectum or bladder
What is involved in the N and M parts of the TNM staging system?
N0 - no nodes involved
N1 - nodes involved
M0 - no metastasis
M1 - mets are present
How is the prostate cancer risk calculated and why is this performed?
- risk is calculated using the TNM stage, Gleason score and PSA value
- this puts patients into 3 groups - low, intermediate or high risk
- it predicts the risk of recurrence after treatment and metastatic spread
When is someone deemed low risk?
- T1c / T2a
- Grade group 1 (Gleason 6)
- PSA </= 10
When is someone deemed intermediate risk?
- T2b/c
- Grade group 2 (Gleason 3+4) or 3 (Gleason 4+3)
- PSA 10-20
When is someone deemed high risk?
- T3a-T4
- Grade group 4 or 5 (Gleason scores 8-10)
- PSA >/= 20
What were the major findings from the PROTECT study?
- there is no difference in mortality / overall survival for radical prostatectomy, radical radiotherapyand active surveillance indicated with PSA
- those undergoing active surveillance have radical treatment when PSA levels rise
- there is a greater risk of metastatic cancer developing during active surveillance
- radical treatment upfront reduces the risk of metastatic cancer by 50%
What happens in external beam radiotherapy?
radiotherapy is delivered in an arc around the patient
the radiotherapy plan aims to target most of the radiotherapy to the area around the prostate gland
What is involved in prostate brachytherapy?
What is a major benefit to this method?
- this involves multiple needles inserted into the prostate gland transperineally to deliver internal radiation
- allows for a higher dose of radiation and improved cancer control
How do you decide which treatment option is the best for that patient?
What risks are associated with these?
Surgery:
* good option for men < 70 with no co-morbidity (due to GA)
* risks of long term incontinence & impotence
Radiotherapy
* non-invasive
* good option for older men or those with comorbidity
* risk of long-term bowel problems
Brachytherapy
* good option for fit men with no comorbidity
* avoid in men with large prostates or significant urinary symptoms
What are the typical symptoms of metastatic prostate cancer?
What imaging methods could be used to show this?
- prostate cancer commonly metastasises to the bone
- this presents with bone pain and general malaise
- a technetium bone scan will show widespread mets around the axial skeleton
- XR will show sclerotic mets
What are the treatments available for prostate cancer with bony mets?
- the main treatment is lifelong androgen deprivation therapy
- other systemic treatments may be used in fit patients - chemotherapy & abiaterone / enzalutamide
- persistent bony pain can be treated with palliative radiotherapy
How does androgen deprivation therapy work?
- prostatic cells require testosterone to divide and the cancer needs it to grow
- androgens are produced by the testes and adrenal gland
- anti-androgens block the pathway at this level
- GnRH agonists / antagonists block the pathway at the level of the pituitary-hypothalamus feedback loop
What are the adverse effects of androgen deprivation therapy?
- hot flushes
- reduced sexual function / shrinkage of penis + testes
- loss of muscle bulk + strength
- memory effects + mood disturbance
- 10% weight gain and diabetes risk
- osteoporosis / higher fracture rate
side effects are due to medical castration and reduced testosterone
How does androgen deprivation therapy affect cardiovascular risk?
- ADT is associated with a 5% increase in CV mortality
- events often occur early (within first 12 months)
- increases risk of stroke and PVD
- lack of testosterone causes progression of atherosclerosis
- metabolic syndrome is associated with obesity, altered lipids and risk of DM
What medications are typically used for anti-androgen therapy?
LHRH agonists
- e.g. goserelin / zoladex
- these initially cause a rise in testosterone for around 2-3 weeks before lowering it
What may be given during the first few weeks of treatment with anti-androgen therapy?
anti-androgens
- e.g. flutamide / bicalutimide
- these are used to compensate for the initial rise in testosterone when treatment is started
