At the May 2002 meeting, Professor Marshall, B.M., B.S., M.D., F.R.A.C.S., Urological Department, Royal Adelaide Hospital, gave the group an excellent overview of new research in the area of prostate cancer. He discussed the research findings presented at the recent Australasian Urological Society meeting at which prostate cancer research made up approximately one third of the presentations.
" The PSA test is familiar to all prostate cancer patients. It is an uncertain test. PSA tests are very useful for managing prostate cancer but not so useful for diagnosis. Urologists now look at diagnosing prostate cancer between PSA levels of 2 and 9. This is because treating cancer before the PSA reaches 9 gives a greater chance that the cancer will be confined td the prostate. However, rises in PSA at this level can Often be due to BPH (benign prostatic hyperplasia). Clinicians may be doing too many tests and treating benign tumours.
" Between 20% and 30% of men have cancer cells in the prostate but many will not go on to develop prostate cancer. 3% of men will die from prostate cancer, 10% will develop significant symptoms and a large proportion will not have any problems. We need to distinguish between 'good' or benign cancers and 'bad' or aggressive cancers.
" Different grading systems are being developed in addition to the Gleason score.
" How do we treat localised prostate cancer? Currently options are no active treatment, surgery , radiotherapy, or brachytherapy. A group in the UK are currently setting up a randomised controlled trial to answer the question of which treatment is the best treatment. Such trials are extremely difficult to undertake! There are difficulties in recruiting patients, and in randomising, patients. It seems that the study will need to screen between 50 and 60 thousand men to get sufficient numbers for the actual study, it will and take 5 years to recruit patients and 5 years to collect data, and will cost around 15 million pounds!
" Researchers have been looking into the present practice of removing lymph nodes in the pelvis during surgery and checking them for cancer. Due to earlier detection these nodes are virtually never positive and it may be better to stop the practice as there can be side effects from the y unnecessary removal of lymph nodes.
" There are advances in nerve sparing surgery. Researchers in the eastern states are trailing nerve grafts to preserve sexual function after a radical prostatectomy
" Tissue glues are also being developed to replace stitches. '
" Brachytherapy (the implantation of radioactive seeds into the prostate) only seems to be effective in localised low-grade cancers. These may be the cancers that do not require treatment in the first place! If you have a PSA >10 or a Gleason >7 then brachytherapy is probably not the treatment for you. Brachytherapy will be available in Adelaide in the near future.
" Due to men surviving longer with prostate cancer, clinicians are now starting to see more side effects from Hormone Treatment. Not only does this treatment effect libido but it may also have long-term effects on cognition, emotion, body fat distribution and osteoporosis. It has been suggested that Intermittent Hormone Therapy may prevent some of these side effects. Researchers are also testing patient's bone density and treating osteoporosis with a drug called Papidronate (a mere $3000 per injection').
Research Gene Therapy
We know a lot more now due to the Human Genome Project. One recent study looked at 116,000 gene samples from prostate tumours and found 36 genes that might be implicated in prostate cancer.
Research at the Hanson Centre
Professor Marshall and colleagues are currently looking at androgen receptors. Prostate cancer is hormone dependent but after exposure to a hormone blocking drug the cancer can mutate and become resistant. Their research is looking at ways of stopping this by creating a mirror image androgen receptor that will lock on and block out mutations.
Q: Hormone Therapy v s Orchidectomy. Which is better?
A: Orchidectomy might have fewer side effects but if cycling different hormone therapies does work then it might be better not to have the operation and keep your options open.
Q: What's your opinion of complimentary therapies?
A: We honestly don't know which is the best option out of no treatment, radical prostatectomy or radiotherapy. Individuals need to weigh up the best evidence at the time. We don't know much about complimentary therapies either. Some cancers are slow growing, we need to know if improvements are due to these therapies or just to the natural history of the cancer.
Q: Is there any difference between Zoladex
A: Only in the way they are administered! There are no differences in side effects or effectiveness.
Q: Is exercise protective against the side effects of Hormone
A: Yes, keeping up an active life style will preserve muscle mass.
Q: I have heard of the idea that prostate cancer is systemic
and some of the cells may have already escaped. If this is the case this means
that radiotherapy may be a better option than surgery.
A: The standard doubling rate of a prostate cancer cell is 40 days. To get a million cells, which is about the size of an early tumour, the cancer must have been there for some time. Hence, even with early detection, we cannot rule out that some cancer cells may have escaped and survived beyond the prostate.
Q: Radical prostatectomy is seen as the gold standard, is
this still the case?
A: Radical prostatectomy only works if the cancer is confined to the prostate- yes, in that the best long- term survival figures come in series (?) of prostatectomies. However, in choosing a treatment option, all factors such as quality of life and potential side effects need to be taken in account.
Gerry, our President then thanked Professor Marshall for his very informative lecture and presented him with a bottle of Peter Lehman's very best red.
Notes made by Melissa Dougherty.