Guest Speaker: Dr Alan Stapleton M.B.,
Guest Speaker Dr Stapleton addressed a packed seminar room for his annual talk to the PSA Adelaide group for over 2 hours(July 2002)! He covered such a lot of ground that I could fill the next 12 pages with the notes I scribbled during his talk.The following is a summary of the main points from his presentation.
Dr Alan Stapelton
Androgens drive the development of sex organs such as the prostate.What
is the biggest sex organ in the male body?: the brain (laugh). Other organs
include the testes and the adrenal glands.Testosterone is an androgen; it circulates
in the blood. Weaker androgens come from the adrenal glands (which account for
about 10% of testosterone activity).Testosterone turns on prostate development
and feeds prostate cancer cells.
Dr Alan Stapleton
In a prostate cancer cell testosterone is converted to 5DHT (5-10 times MORE active than testosterone!) We can turn off this hormone system to control prostate cancer growth
TYPES OF HORMONE TREATMENT
The oldest form of hormone treatment for prostate cancer is Orchidectomy (surgical castration).This was first carried out in the 1940s.There are positives and negatives to this treatment. It is less expensive than constant hormone therapy, and may have less of the cognitive side-effects that are now being associated with some medications, but there is no turning back, it is not practical to alter treatments or try intermittent therapy.
Injections such as Lucrin and Zoladex work on the brain. Large doses of hormones cause the pituitary gland to shut down hormone stimulation of the testicles.
Tablets such as Androcur, Cosudex, Eulexin etc work on the prostate cancer cells.These are often taken in conjunction with injections.These drugs can, on occasions, promote some prostate cell cancer growth over time, in part related to mutated receptors in the prostate cancer cells. These agents are not commonly used on their own but can have less side effects, in particular less negative impact on sexual function.
In the end, treatment decisions are always going to be about COMPROMISE. No treatment is without risk of side effects.You need to understand what youre willing to trade. 99% of the time you have TIME to decide on your prostate cancer management.
WHEN IS HORMONE TREATMENT USED?
In clinically localised prostate cancer specialists treat with intent to cure using surgery or radiotherapy. Hormone treatment may be used here to shrink the tumour before treatment. Hormone treatment has not been shown to be advantageous before surgery, but it does appear to be helpful in some circumstances when used in conjunction with radiotherapy,
Hormone treatment is also used when PSA levels rise after initial treatment has failed to control the cancer. The timing of introduction of hormone therapy in this situation is controversial.
Second line hormone therapy is used when primary hormone treatments are not working. The tablets are often withdrawn and another added after a while to assess response. Prednisolone is a potent steroid and suppresses the adrenal steroids. Perhaps 10-20% of men respond to second line treatments with better health.
Once you have been treated with tablets and injections there is no particular advantage in then moving to an orchidectomy.
SIDE EFFECTS OF HORMONE TREATMENT
Hormone Treatment can lead to reduced libido, erectile dysfunction, hot flushes/sweats, decreased muscle mass/strength, weight gain, osteoporosis (this is not usually clinically important until after at least 12 months of therapy), change of body hair, cognitive changes, and psychological changes amongst others.
It is important to monitor these changes and to maintain a good diet and a reasonable level of physical activity. Many of these side effects can be managed with some success.
PSA LEVELS CAN BE MISLEADING
Typically, PSA is a marker of proliferation of prostate cancer cells. However, PSA becomes a poorer marker of prostate cancer volume once you have been on hormone therapy. Prostate cancer is a highly heterogenous cancer, you can have a low PSA and high volume disease, or a relatively high PSA and disease localised to the prostate. Clinicians need to have more information about the cancer than just the PSA, such as digital examinations, CT or MRI scans and whole body bone scans.
INTERMITTENT VS CONTINUOUS HORMONE TREATMENT
Intermittent hormone treatment has grown in popularity but to many remains experimental. Research with animals suggests that intermittent hormone treatment may prolong life and reduce side-effects. Such advantages are not apparent in published human trials.
BEYOND HORMONE TREATMENT
Chemotherapy may be helpful to 20% of patients. Drugs such as Paclitaxel and Estramustine are used in the US, but to a lesser degree in Australia. For chemotherapy to be considered useful it should ideally be delivered at home, have a high impact on the cancer but low side-effects.
Spot Radiotherapy.This procedure knocks out prostate cancer cells that are causing problems such as pain in the bones.
Strontium 89, a radioactive compound, can also be used to control bone pain when it is widespread. It can improve quality of life but does not significantly prolong life expectancy.
For men with advanced stage prostate cancer: make use of supportive care services such as palliative care specialists, nurses, community services, religious groups. Dont feel guilty that your cancer has progressed whilst someone elses has not.
No one should suffer in silence. If you are having difficulties, speak up! Doctors are there to help you and your families.
from notes taken by Melissa