Study finds newer breast cancer drugs save lives
WASHINGTON (Reuters) - Women with breast cancer who switch from tamoxifen to a newer class of drugs called aromatase inhibitors live longer, Italian researchers reported on Monday.
Their study, published in the journal Cancer, adds to a growing body of evidence that the new drugs are far safer, preventing cancer with fewer side effects than tamoxifen.
Dr. Lauren Cassell of Lenox Hill Hospital in New York said the research is changing how doctors treat breast cancer patients after their tumors are surgically removed.
"If they have been on tamoxifen we are switching them to an aromatase inhibitor. If they are newly diagnosed we are using an aromatase inhibitor instead of tamoxifen," she said in a statement.
But tamoxifen remains the main option for younger women with breast cancer. "Aromatase inhibitors are only for women who are post-menopausal," Cassell said.
Tamoxifen transformed breast cancer therapy when it was shown to reduce the risk of cancer recurrence by close to 50 percent. It was also an easy-to-take pill. But the drug raises the risk of death from strokes and endometrial cancer.
Then a newer class of drugs, the aromatase inhibitors, was developed.
Dr. Francesco Boccardo of the National Cancer Research Institute and the University of Genoa in Italy and colleagues looked at two studies of 828 women.
About half the women got tamoxifen for five years, as was once recommended, and half got tamoxifen at first and then switched to an aromatase inhibitor after two or three years.
The women who switched were much less likely to die of breast cancer or of anything else, Boccardo reported.
"This pooled analysis provides solid evidence that switching to an aromatase inhibitor following a few years of tamoxifen treatment implies a mortality benefit over continued tamoxifen and that the benefit on breast cancer-related mortality is mainly due to the effect of switching," they wrote.
German researchers reported similar findings in November.
Aromatase inhibitors include anastrozole, made by AstraZeneca Plc under the brand name Arimidex, and exemestane, made by Pfizer Inc. under the brand name Aromasin.
Tamoxifen -- long the drug of choice for preventing breast cancer -- blocks estrogen, which can help fuel the growth of tumors in some cases.
It is sold by AstraZeneca under the name Nolvadex but now is marketed by several generic drug makers.
Breast cancer is the second leading cause of cancer death among U.S. women, after lung cancer. More than 200,000 people are diagnosed and another roughly 40,000 die from it each year, according to the American Cancer Society.
What breastcancer.org says about this article…
Study finds newer breast cancer drugs save lives
In November 2006 Breastcancer.org reviewed a study that showed that aromatase inhibitors are probably the best hormonal therapy medicine for post-menopausal women with hormone-receptor-positive, early-stage breast cancer. The study reviewed here underscores those results. Italian researchers found women who switched from tamoxifen to an aromatase inhibitor lived longer than women who stayed on tamoxifen.
After surgery, post-menopausal women with hormone-receptor-positive cancer usually take hormonal therapy medicine for at least five years to reduce the risk of the cancer coming back. Treatment that comes after surgery or another initial treatment is called adjuvant therapy.
Tamoxifen used to be the only hormonal therapy choice. Now there are three aromatase inhibitors available: Arimidex (chemical name: anastrozole), Aromasin (chemical name: exemestane), and Femara (chemical name: letrozole). Once aromatase inhibitors became available, many women switched from tamoxifen to an aromatase inhibitor. This was the case for half the women in this study (the other half received only tamoxifen). Based on earlier studies like this one, many women now receive an aromatase inhibitor first, instead of tamoxifen.
Tamoxifen is still a better option than an aromatase inhibitor for younger, PRE-menopausal women diagnosed with breast cancer. While an aromatase inhibitor is the best hormonal therapy to start with after initial breast cancer treatment for post-menopausal women with early-stage, hormone-receptor-positive breast cancer, tamoxifen is still a good choice. For a number of reasons, including side effects and cost, tamoxifen may be a better choice for some women.
When you're deciding on a treatment plan, keep two things in mind:
- Every woman responds differently to treatment. What works for someone else may not work for you and what works for you may not work for someone else.
- Your treatment plan is not written in stone. You can always change treatments if another treatment has greater benefits and fewer side effects.
If you're a post-menopausal woman with hormone-receptor-positive, early-stage breast cancer, talk to your doctor about the pros and cons of aromatase inhibitors compared to tamoxifen. If you're currently taking tamoxifen, discuss whether switching to an aromatase inhibitor makes sense for you. Together, you can decide on a treatment plan that is best for YOU.
