Re: Aspirin cuts stomach cancer risk

Well, the influence of testosterone in breast cancer has / is being
considered causative by itself, not being converted to estradiol. For
example: ".testosterone might be more strongly associated with [breast
cancer] risk [in women] than estradiol." (Journal of the National Cancer
Institute 2002; 94: 606-616). Since then other reports are suggesting the
same: "CONCLUSIONS: This study provides further evidence that high levels
of circulating testosterone increase the risk of developing breast cancer in
postmenopausal women. The cancers that develop are mainly estrogen receptor
positive. Although HER2(+) and HER2(-) breast cancers were both associated
with high total testosterone, they showed opposing associations with
estrogen." Cancer Epidemiol Biomarkers Prev. 2009 Jan;18(1):169-76


"Ed Friedman" <ed@xxxxxxxxxxxxxxxxx> wrote in message
news:dh0kl.1$D%7.0@xxxxxxxxxxxxxxxxxxxx


Ray Laughton wrote:
I don't think so. If your theory was correct, breast cancer would be much
more common in
men than it is in women..

ray


James Howard <jmh.anthropogeny.com@xxxxxxxxx> wrote:

It is my hypothesis that increased testosterone may cause breast cancer
(International Journal of Cancer 2005; 115: 497). In some research,
testosterone has been connected with increased stomach cancer. Aspirin
and
other NSAIDs reduce testosterone production. I suggest this research
(British Journal of Cancer (2009) 100, 551-557) may be explained by a
reduction in testosterone levels.

James Michael Howard

Fayetteville, Arkansas, U.S.A.

Actually, you are both correct. Breast cancer (and prostate cancer) are
ordinarily caused by high local levels of estradiol. This high level of
estradiol is caused by testosterone being converted to estradiol by
Aromatase (which has little or no activity in normal breast and prostate
cells, but very high activity in breast and prostate cancer cells). This
means that if your testosterone level is low enough, you ordinarily cannot
get either breast cancer or prostate cancer.

However, testosterone itself protects against both breast and prostate
cancer. E.g., men with defects that limit their testosterone production
see big increases in their rate of breast cancer. There is a threshold
level for this protection, with prostate cancer having a much higher
threshold than breast cancer does.

Putting this all together, with no testosterone, there is little or no
chance for either cancer. As the level of testosterone rises, you have to
reach a minimum threshold at which you can now get the cancer. As your
testosterone level rises still more, your risk increases as the
testosterone level increases. However, once you reach the high threshold
level appropriate for that cancer, you once again have little or no chance
of getting that cancer.

This also explains why it is so rare to see either of these diseases in
men or women in their teens or early twenties, when testosterone levels
are at their highest. For those interested in the molecular biology of
breast and prostate cancer, there is an article that explains the above
plus much more at http://www.tbiomed.com/content/4/1/28

Ed Friedman


.

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