CANCER GUIDES II
I am at a four day meeting of Cancer Guides II at the Marriott Wardman Hotel in Washington, DC. This is an outstanding event sponsored by the Center for Mind-Body Medicine (cmbm.org). Between CGII and the Food as Medicine program we will be 500 strong at the hotel this weekend! I am very happy to see the scientific approach to integrative medicine thriving in this way. I will have some updates from the CGII conference in next week's newsletter.
Also, in the weeks to come I intend to highlight some of the most important papers presented at the recent annual meeting of the American Society of Clinical Oncology (ASCO). I hope to have some special reports on results from this very important meeting later this summer.
| ASCO Poster Presentations |  | |
| Bristol Myers Squibb Exhibit at the ASCO |  | |
ANTIDEPRESSANTS MAY WIPE OUT BENEFIT OF TAMOXIFEN
It is well known that many women taking the anti-hormonal drug tamoxifen also experience hot flashes. Because of their breast cancer history, however, they cannot not take any form of hormonal therapy to control these troublesome symptoms. Since antidepressants may help control hot flashes, many of the half million women or so women who are taking tamoxifen also take antidepressant drugs.
There has been considerable concern, however, since researchers found that many antidepressants also lower the amount of tamoxifen in the bloodstream. Now, a study presented at the American Society for Clinical Oncology (ASCO) annual meeting showed that patients increase the risk of having their disease recur if they also take the popular drugs Prozac, Paxil and Zoloft while taking tamoxifen. Some attendees called the finding "worrisome."
The new study found that antidepressant drugs that inhibit the CYP2D6 pathway, virtually wiped out the benefit of tamoxifen. The good news is that not all antidepressants had these effects. There are other alternatives that patients could consider, such as Celexa, Lexapro or Luvox along with tamoxifen.
The authors used the medical records of 353 individuals who were taking tamoxifen plus other drugs that might interfere with it. They then checked to see how many were treated for breast cancer in the following two years. Breast cancer recurred in 7 percent of women on tamoxifen alone vs. 14 percent on those taking tamoxifen with Paxil or Prozac (and to a lesser degree Zoloft).
Contradictory Study
However, another study, by Vincent Dezentje, MD, of Leiden University Medical Center in the Netherlands could not find any increased risk from combining tamoxifen with the most popular antidepressants.
"Based on our findings and previous studies, we don't have strong evidence that it's unsafe to use 2D6 inhibitors during tamoxifen therapy," said Dr. Dezentje, in a statement. But the Dutch study was smaller and of shorter duration.
Many doctors at the meeting said they would now recommend against combining tamoxifen with Prozac, Paxil or even Zoloft. in terms of breast cancer recurrence, it is safer to use Celexa, Lexapro or Luvox. Patients might also want to talk to their doctor about possibly taking natural anti-depressants, such as St. John's Wort, sam-E, or 5-HTP, although admittedly these were not included in the ASCO study.
--Ralph W. Moss, Ph.D.
Resources:
Aubert, RE, et al. Risk of breast cancer recurrence in women initiating tamoxifen with CYP2D6 inhibitors. J Clin Oncol. 2009; 27(15S): Abstract CRA508.
Dezentje V, et al. Concomitant CYP2D6 inhibitor use and tamoxifen adherence in early-stage breast cancer: a pharmacoepidemiologic study. J Clin Oncol. 2009; 27(15S): Abstract CRA509. To check out my latest Current Topic report, Cancer, Enzymes and Trophoblasts: The Legacy of John Beard, DSc. (click here) |
