Linda,
First, congrats on being "all clear" with your recent testing ... that's super!
The topic that you have raised is a bit complicated, and somewhat controversial for HER-2 positive, ER+ women. As you know, for decades, Tamoxifen has been the "gold standard" anti-estrogen treatment for women with breast cancer. In fact, ASCO has not changed its tamoxifen recommendation, despite the findings of three recent major studies that found three different aromatase inhibitors (Arimidex, Femara and Aromasin) superior to tamoxifen in terms of preventing cancer recurrence. Unfortunately, you have to be post-menopausal to utilize the aromatase inhibitor drugs. There is, however, no long term survival data available with respect to these AI studies.
Doctors, as you know, love long-term survival data and tamoxifen has been around a long time. Doctors feel very comfortable with its action and fully understand its long-term side effects. If you go to
www.her2status.com, you'll find a series of studies that suggest that HER-2 positive women are generally resistant to the effects of tamoxifen. Three studies presented at the website are inconclusive on this point. There is some controversy circling this issue.
The aromatase inhibitor studies involving Arimidex, Femara and Aromasin are impressive in terms of preventing recurrence. These studies, however, are fairly short-term studies. But, the effects were so impressive, the Femara and Aromasin studies were discontinued mid-trial to provide the control group women the opportunity to switch from Tamoxifen to Femara or Aromasin. The Femara and Aromasin studies involved women who were on Tamoxifen for some period of time prior to switching to Femara or Aromasin. If you go to
www.breastcancerupdate.com and read some of the more recent issues, you'll find that more and more oncologists are switching to aromatase inhibitors for their post-menopausal, ER+ breast cancer patients.
Now, you can only use an aromatase inhibitor if you are post-menopausal. So, tamoxifen is generally used for pre-menopausal women unless menopause is induced through surgery or suppression hormonal treatment with Zoladex or Lupron. Pre-menopause, most of the estrogen produced by a women is produced by the ovaries. Post-menopause, most of the estrogen is produced in the tissue (including fat) and by the adrenal glands. Tamoxifen works by blocking the estrogen receptor on cancer cells. AIs work by blocking the enzyme "aromatase" which is needed as a precursor for the body's production of estrogen. So, AIs tend to do a better job of reducing the overall amount of estrogen in a woman's body.
The decision to induce menopause is obviously a serious one. It should be discussed with your oncologist and gyn. The situation in which ovaries are generally removed, based upon my reading, relates to those women who have been assessed as extremely high risk for breast and ovarian cancer through genetic testing (i.e., BRCA 1 and BRCA 2 testing). Unless you were tested as high risk in this fashion, I not sure that you want to pursue surgery. However, you should discuss this option with your doctor(s).
A non-surgical method to achieve menopause is through use of Zoladex or Lupron. You should talk to your doctor(s) about this option as well.
If you are close to menopause, it may be that your doctor wants you to use tamoxifen until you reach menopause and then make the switch to AIs. This decision, as you know, is very personal, and depends upon your research and the input from your doctor(s). My personal opinion is that a HER-2 positive, ER+ breast cancer patient should seriously look into the use of AIs. Both tamoxifen and AIs have side effects and this fact cannot be ignored. A big side effect of AI use is bone loss.
Also, keep in mind that many researchers believe that HER-2 positive women will eventually become resistant to any one anti-estrogen drug. Many believe that the best way to deal with this issue is to use tamoxifen and AIs in a single drug sequential manner.
I hope this sheds some light on your issue.
Linear Mode
