Prostate cancer Flashcards
What pathway is disrupted in most prostate cancers?
androgen-signalling pathway
What is linked to familial prostate cancer?
inactivation of PTEN
Which other gene is linked to prostate cancer?
BRCA 2
What are the symptoms of prostate cancer?
problems with urination
back pain
haematuria
spread to other organs –> severe bone pain
What are the majority of prostate cancer deaths due to?
metastatic disease
What is the prostate?
exocrine gland that produces seminal fluid
What is PSA?
component of seminal fluid
What is blood PSA like normally?
undetectable
What blood PSA level indicates possibility of prosthatic disease?
4ng/ml
Why might benign prostate hyperplasia be problematic?
urethra constriction
What are the other causes of raised PSA?
mechanical damage, prosthatitis
What methods are used to grade tumours after positive PSA results?
biopsy + Gleeson scoring
What gene appears to be increased in prostate cancers that subsequently metastasise?
EZH2
What is the argument against routine PSA testing?
possibility that lesion, if left alone, would not be problematic in his lifetime –> causes anxiety/stress + invasive tests
What are some treatments for prostate cancer?
radical prostatectomy
external beam radiotherapy
brachytherapy
hormone therapy
What are some side effects of radical prostatectomy?
incontinence
impotence
When is radical prostatectomy performed?
PSA < 12ng/ml
age < 70
What is brachytherapy and when can it be used?
radioactive ‘seeds’ planted in prostate
used if tumour is contained to the prostate
What are the side effects of radiotherapy?
incontinence, sexual dysfunction
How does hormone therapy work?
LHRH analogue –> overstimulates LHRH receptor –> desensitised –> X LH + testosterone production
When is external beam therapy be used?
When the cancer is not affecting other organs
What are the side effects of hormone therapy?
osteoporosis decreased libido anaemia muscle atrophy memory loss
What is a key change in prostate cancer progress?
change to androgen independence
What is the evidence that the androgen receptor is required for prostate cancer progression?
even in androgen-independent tumours, androgen receptor expression is not lost, and often increased
What are the possible causes for growth in the absence of circulating androgens?
amplified response to low residual levels of androgens
mutation of androgen receptor –> activated by other ligands
How might the androgen pathway be bypassed altogether?
loss of PTEN
