Femara BenefitsSome more than Others
First an important follow up comment to Wednesday's blog re the benefit of ten years of Tamoxifen rather than five years ( read Wednesday's blog). I have had calls and questions about this from many women and have talked to several of our senior medical oncologists about it. Obviously, the most important comment is to talk with your own doctor about the meaning for you. As always, there is not a one size fits all response. However, the general sense seems to be:
- This likely applies to women who are taking one of the AIs, but will need more thought and individual conversation.
- Unclear whether it will be recommended that women who stopped taking Tamoxifen a year or more ago will be told to resume the medication. Again, talk to your doctor.
And, now, today's news from San Antonio continues with the theme of information becoming more specific as better understanding is reached about what helps a particular woman. This study about the value of Femara found that it was more helpful to women with some kinds of ER positive breast cancers than others. Will this mean that the others will be transitioned to one of the other AIs? Seems like an obvious question, and I surely don't know the answer. If this were me, however, I would certainly talk to my doctor about it.
Here is the beginning and a link from Medpage:
Femara Benefits Vary by Breast Cancer Type
By Michael Smith, North American Correspondent, MedPage Today Published: December 06, 2012
Reviewed by Dori F. Zaleznik, MD; Associate Clinical Professor of Medicine, Harvard Medical School, Boston
SAN ANTONIO - For postmenopausal women with breast cancer, 5 years of adjuvant treatment with letrozole (Femara) outperformed tamoxifen over 8 years of follow-up, a researcher said.
Women with estrogen receptor-positive and HER2-negative cancer did significantly better in both disease-free and overall survival if they took letrozole, according to Otto Metzger Filho, MD, of Dana-Farber Cancer Institute in Boston.
But the benefit varied markedly over different cancer histologies, with the advantage going to lobular over ductal carcinomas, Metzger Filho reported at the San Antonio Breast Cancer Symposium here.
In addition, Metzger Filho reported, letrozole outperformed tamoxifen if women had so-called luminal B tumors, with a high level of the protein Ki-67, which is associated with greater proliferative activity.
The findings come from the so-called BIG 1-98 trial, which is studying the comparative efficacy of the two substances in postmenopausal women with breast cancer.
Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
Explain that a previously unplanned analysis of the BIG 1-98 trial found that letrozole was more effective than 5 years of tamoxifen for both progression-free and overall survival for postmenopausal women with estrogen receptor- positive, HER2 negative breast cancer.
Note that the effect of letrozole was most pronounced for those with lobular as opposed to ductal breast cancer and more for luminal B than A disease.