FRIDAY, April 15 (HealthDay News) -- Is estrogen breast cancer's friend or foe?
A recent study in the Journal of the American Medical Association, which analyzed data from the massive Women's Health Initiative, suggested the latter when it found a reduced risk of breast cancer in women who had been on short-term estrogen therapy.
This seemed to contradict years of cautions that estrogen therapy -- once widely prescribed as an antidote for the symptoms of menopause and to prevent chronic diseases -- fuels estrogen receptor-positive breast cancers.
In fact, this wily hormone can be both, according to an editorial in the April 10 issue of Cancer Prevention Research.
"Estrogen is bad at the right time, and estrogen is good at the right time," said editorial co-author V. Craig Jordan, considered the "father" of tamoxifen and other anti-estrogen treatments for breast cancer.
It's true, estrogen is necessary for cancer cells to grow and multiply, but when the cancer cells develop in an environment where estrogen hasn't been present for a while, they are killed off by an unexpected flood of the hormone, he explained.
A state of estrogen deprivation can come years after menopause, when production of estrogen naturally stops or even after a woman has been receiving anti-estrogen therapy for breast cancer.
In such a state of deprivation, Jordan said, "cells grow that are not independent of estrogen. They have learned to grow with just a little tickle of estrogen. They're hanging on with a sort of starvation diet.
"When they start to form tumors and we put back normal-dose estrogen, the cells see this as a death signal because they're suddenly given a massive concentration of high-octane fuel. It's a complete overdose. Like a starving person, you can't just say sit down and eat all you want at McDonald's because you'll kill them," added Jord
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