Metastatic Prostate Cancer and Testosterone
Posted: Mon Jul 07, 2008 8:25 pm
Metastatic Prostate Cancer and Testosterone
Advanced, or metastatic, or "high-risk", prostate Cancer is traditionally difficult to treat. Most metastatic cancers are hard to treat.
Metastasis generally defines the boundary between benign and aggressive tumors. Some tumor cells develop the ability to detach themselves from the tumor itself, move into the blood stream, and travel to distant parts of the body, where they settle and multiply.
As long as the cells are all in the same physical location, there may still be options for direct treatments like surgical removal, radiation treatment, and cryo-treatment. For the prostate, these are often called "low risk" tumors.
Please keep in mind that there are significant differences between individuals, at least as great as the gross physical differences we all know. The same is true of Cancers. It is easier to discuss the statistics than individual cases, because there are such a wide range of possibilities. No matter what the statistics are, they don't make any difference whatsoever to one individual case. It is very difficult to make a diagnosis with extreme precision on any one individual, before actually applying the scalpel.
From the literature, it appears that pre-metastatic cancer is qualitatively different from advanced cancer.
The distinction is so clear-cut that it might be appropriate to treat and discuss them as wholly separate diseases.
An effective treatments for one type can be an accelerant for the other.
Something that low-risk and high-risk cancers have in common is a requirement for Testosterone.
The various methods of castration - surgical, chemical, vaccination, all serve to dramatically lower the serum testosterone levels. Prostate cells, and low-risk prostate cancer cells, need testosterone to be present. In its absence they can and do die. For castrates, the prostate cells and low-risk prostate cancer cells commit cell suicide - apoptosis. Not all at once, of course, but progressively. Long term castrates experience distinct and substantial shrinkage of the prostate. Again, your mileage will vary, with no "might" about it.
http://ajp.amjpathol.org/cgi/content/ab ... 368?ck=nck
Treating high-risk prostate cancers with Testosterone causes a significant increase in their growth rate. The effect can be so great that castration paradoxically risks the patients life, what is left of it.
http://clincancerres.aacrjournals.org/c ... l/12/1/169
The effect is called tumor flare, and has been remarked upon by other posts on this site, directly and indirectly.
http://prostatecancer.about.com/od/trea ... herapy.htm
http://www.prostate-cancer-institute.or ... erapy.html
When the serum levels of Testosterone are reduced by some drugs the pituitary, in a feedback mechanism, tries to compensate by producing more GnRH, the signal to produce Testosterone. This drives the adrenal glands to over-produce Testosterone and flooding the body with it. If high-risk tumor masses are in close proximity to critical functions - the heart or arteries for example - then rapid high-risk tumor growth can interfere with proper function, possibly enough to kill the patient.
It would seem that near elimination of Testosterone would be the perfect solution, yet the effect of reducing Testosterone to anorchic (castrated) levels has, at most, a temporary effect on high-risk cancer.
Further investigation has revealed that high-risk prostate cancers, in the absence of Testosterone, will develop the ability to produce their own Testosterone locally, within the tumor. After an initial phase of shrinkage and cell death through apoptosis, the cancer comes back.
High-risk prostate cancers often develop multiple receptors on their external surfaces to more effectively detect the Testosterone signal. When the sensitivity of the tumor goes up a hundred- or a thousand-fold, treatments to reduce serum Testosterone levels by only 98% seem to be frivolous.
Also, for some high-risk prostate cancers, the Testosterone receptors themselves are degraded. The result is that they are promiscuous in their recognition of steroid-like compounds, and may begin to trigger on steroids like Estrogen, or some of the blocking medications. The medication itself can begin to promote the cancer.
In contrast to the regulated system in the body where the pituitary produces GnRH in response to Testosterone levels, and the testes produce Testosterone in response to GnRH levels, the high-risk prostate cancers self-regulate - they produce the Testosterone, and then detect it. No amount of interference in the normally regulated system can affect the self-regulated tumor cells.
The paradox is explained. High-risk tumor cells need Testosterone. When they don't get it from their environment, they produce it themselves.
http://www.eurekalert.org/pub_releases/ ... 052708.php
http://www.urotoday.com/61/browse_categ ... ot_androge nindependent__abstract.html
http://cancerres.aacrjournals.org/cgi/c ... 68/11/4447
http://www.modernmedicine.com/modernmed ... ryId=40237
Reading an reviewing all this suggests to me that tumor masses of high-risk prostate cancer contain minute populations of testosterone producing tumor cells. Left alone, rapidly growing tumor cells soon bury the minor population of Testosterone producers, minimizing their access to nutrients.
However, once Testosterone levels are radically decreased, the majority of tumor cells die off, leaving the Testosterone producers to continue. The patient improves temporarily, but only until the population of tumor cells once again rises to a level that threaten the patient's life and well-being.
Advanced, or metastatic, or "high-risk", prostate Cancer is traditionally difficult to treat. Most metastatic cancers are hard to treat.
Metastasis generally defines the boundary between benign and aggressive tumors. Some tumor cells develop the ability to detach themselves from the tumor itself, move into the blood stream, and travel to distant parts of the body, where they settle and multiply.
As long as the cells are all in the same physical location, there may still be options for direct treatments like surgical removal, radiation treatment, and cryo-treatment. For the prostate, these are often called "low risk" tumors.
Please keep in mind that there are significant differences between individuals, at least as great as the gross physical differences we all know. The same is true of Cancers. It is easier to discuss the statistics than individual cases, because there are such a wide range of possibilities. No matter what the statistics are, they don't make any difference whatsoever to one individual case. It is very difficult to make a diagnosis with extreme precision on any one individual, before actually applying the scalpel.
From the literature, it appears that pre-metastatic cancer is qualitatively different from advanced cancer.
The distinction is so clear-cut that it might be appropriate to treat and discuss them as wholly separate diseases.
An effective treatments for one type can be an accelerant for the other.
Something that low-risk and high-risk cancers have in common is a requirement for Testosterone.
The various methods of castration - surgical, chemical, vaccination, all serve to dramatically lower the serum testosterone levels. Prostate cells, and low-risk prostate cancer cells, need testosterone to be present. In its absence they can and do die. For castrates, the prostate cells and low-risk prostate cancer cells commit cell suicide - apoptosis. Not all at once, of course, but progressively. Long term castrates experience distinct and substantial shrinkage of the prostate. Again, your mileage will vary, with no "might" about it.
http://ajp.amjpathol.org/cgi/content/ab ... 368?ck=nck
Treating high-risk prostate cancers with Testosterone causes a significant increase in their growth rate. The effect can be so great that castration paradoxically risks the patients life, what is left of it.
http://clincancerres.aacrjournals.org/c ... l/12/1/169
The effect is called tumor flare, and has been remarked upon by other posts on this site, directly and indirectly.
http://prostatecancer.about.com/od/trea ... herapy.htm
http://www.prostate-cancer-institute.or ... erapy.html
When the serum levels of Testosterone are reduced by some drugs the pituitary, in a feedback mechanism, tries to compensate by producing more GnRH, the signal to produce Testosterone. This drives the adrenal glands to over-produce Testosterone and flooding the body with it. If high-risk tumor masses are in close proximity to critical functions - the heart or arteries for example - then rapid high-risk tumor growth can interfere with proper function, possibly enough to kill the patient.
It would seem that near elimination of Testosterone would be the perfect solution, yet the effect of reducing Testosterone to anorchic (castrated) levels has, at most, a temporary effect on high-risk cancer.
Further investigation has revealed that high-risk prostate cancers, in the absence of Testosterone, will develop the ability to produce their own Testosterone locally, within the tumor. After an initial phase of shrinkage and cell death through apoptosis, the cancer comes back.
High-risk prostate cancers often develop multiple receptors on their external surfaces to more effectively detect the Testosterone signal. When the sensitivity of the tumor goes up a hundred- or a thousand-fold, treatments to reduce serum Testosterone levels by only 98% seem to be frivolous.
Also, for some high-risk prostate cancers, the Testosterone receptors themselves are degraded. The result is that they are promiscuous in their recognition of steroid-like compounds, and may begin to trigger on steroids like Estrogen, or some of the blocking medications. The medication itself can begin to promote the cancer.
In contrast to the regulated system in the body where the pituitary produces GnRH in response to Testosterone levels, and the testes produce Testosterone in response to GnRH levels, the high-risk prostate cancers self-regulate - they produce the Testosterone, and then detect it. No amount of interference in the normally regulated system can affect the self-regulated tumor cells.
The paradox is explained. High-risk tumor cells need Testosterone. When they don't get it from their environment, they produce it themselves.
http://www.eurekalert.org/pub_releases/ ... 052708.php
http://www.urotoday.com/61/browse_categ ... ot_androge nindependent__abstract.html
http://cancerres.aacrjournals.org/cgi/c ... 68/11/4447
http://www.modernmedicine.com/modernmed ... ryId=40237
Reading an reviewing all this suggests to me that tumor masses of high-risk prostate cancer contain minute populations of testosterone producing tumor cells. Left alone, rapidly growing tumor cells soon bury the minor population of Testosterone producers, minimizing their access to nutrients.
However, once Testosterone levels are radically decreased, the majority of tumor cells die off, leaving the Testosterone producers to continue. The patient improves temporarily, but only until the population of tumor cells once again rises to a level that threaten the patient's life and well-being.