O, The Oprah Magazine: The Women's Health Initiative [a major government study on postmenopausal women] recently made headlines about hormone replacement therapy [HRT]: Out of 10,000 women taking combined HRT—estrogen plus progestin—for a year, eight more will develop invasive breast cancer than in a similar group not taking hormones. Should we worry about this?
Norton: Eight out of 10,000 per year is quite a lot, especially when you're talking about people taking many years of treatment. All of the evidence is very clear that there's a higher incidence of breast cancer in women who take hormones—and the longer you take them, the higher the risk.
Love: We have not yet confirmed that taking estrogen alone increases breast cancer. But it's likely to do so by about one percent a year. There simply is no good justification for long-term use of HRT. The current thinking is: short-term use for those with bad menopausal symptoms that really interfere with their lives. And "short term" means three to five years.
O: But if you go off HRT, won't you be at a disadvantage when it comes to osteoporosis?
Norton: Not at all. Non-hormonal osteoporosis drugs called bisphosphonates (Fosamax, Actonel) have been observed very carefully, and there's no evident breast cancer risk. Another good drug option is the "designer estrogen" raloxifene (sold as Evista). Unlike the estrogen in HRT, raloxifene is a "selective estrogen receptor modulator," which acts like an estrogen on bone but like an antiestrogen on breasts. And women who take it have a 50 percent reduction in new breast cancer incidence compared with those not on the drug.
Love: I tend to hedge about that last point, because the only study was done on women with osteoporosis, and those women have a lower risk of breast cancer to start with. That's because they have low levels of hormones. Women with strong bones have more breast cancer.
Love: In young women, breast cancer is relatively rare, so the slight increase of breast cancer risk caused by the Pill is not very significant. The concern is that doctors are now giving it to women in their forties around perimenopause, even menopause, saying it's a way to treat the symptoms. And in that age group, breast cancer is not so rare.
Norton: Birth control pills are an estrogen-progesterone combination, so they bring up the same fears as HRT. Some disagree with me, but I just don't see a reason to take the Pill—even for younger women. The fact is, breast cancer cells, at least in the formative stages, like estrogen. So the more continuously you feed them the estrogen, the greater the likelihood you'll have a malignancy. With the sexually transmitted diseases that we have to worry about nowadays, I think barrier methods make a lot more sense.
O: Are there any breakthroughs in sight?
Norton: People should keep their eyes on cancer vaccines. We're working on vaccines for breast, ovarian and prostate cancer. And I think there's still a lot of promise in the antiangiogenesis approach—drugs that interfere with the formation of new blood vessels that feed tumors.
Love: Several companies are looking at why we have to take out tumors at all, as long as we kill them—by freezing, lasering, or microwaving. One company is working on a balloon that you can stick into the biopsy cavity, fill with radiation for a day or two, and then be done. There's another company that's looking at giving the radiation right in the operating room.
O: Will we ever conquer this disease?
Norton: Even in a few decades, breast cancer may be one of the diseases that is just a matter of history.
Love: I really think we're going to eradicate it in our lifetime.