New Breast Cancer Treatments and Their Side Effects
The annual Charles A. Coltman, Jr. San Antonio Breast Cancer Symposium, held at the end of December, is the premier yearly event for the international community of oncology professionals, researchers, members of the media, and anyone whose work life focuses or touches on breast cancer. This year, over 8,000 attendees spent four days absorbing seminars and keynote presentations devoted to up-to-the-minute, state-of-the-art information on breast cancer and breast cancer research. Here are some of the highlights from this year’s forum:
Knocking weeks off the long haul of radiation:
You’ve been there, right? Most of us have. The every-day trip to the hospital or cancer center for 10 minutes’ worth of radiation. If you live close by, you probably have to take a couple of hours off work to get it done. But if you’re traveling any kind of distance… well, it can mean up to an entire day devoted to those 10 precious minutes–for up to seven consecutive weeks. Clearly, even beyond its side effects, radiation can be a major treatment hurdle for a woman to clear.
HRT to the rescue! A recently completed Canadian clinical trial compared standard radiation to Hypofractionated Radiation Therapy, where women with node-negative breast cancer were given a higher dose of radiation for a lesser number of days. After following the participants for a median of 12 years, results showed basically no difference in rate of survival, rate of recurrence, or types/severity of side effects. HRT reduced the schedule from 7 to 4 weeks; still a slog, but a shorter one.
Bottom line: It’s not widely available yet, but if radiation looms in your future, it’s worth seeing if HRT is an option.
Arimidex vs. tamoxifen: growing data points to Arimidex:
For post-menopausal women with hormone receptor-positive (ER/PR-positive) breast cancer, it’s looking more and more like tamoxifen, the “gold standard” of hormone therapy for 30 years, might become a thing of the past.
Results of the long-term ATAC study (Arimidex, Tamoxifen, Alone or in Combination) become clearer with each passing year: after a median follow-up that’s now reached 8 years, Arimidex, or Arimidex in combination with tamoxifen, prevents breast cancer recurrence more effectively than tamoxifen alone. Arimidex (or the combo) also prevents new cancer in the second breast more effectively than tamoxifen alone.
The downside? Women taking Arimidex are more likely to have bone issues, including increased fractures, though this risk disappears once the Arimidex is stopped. And, though there’s a difference in recurrence risk, the survival rate between the two groups remains the same.
Bottom line: If you’re post-menopausal, ER/PR-receptive and have been taking tamoxifen for a couple of years, ask your oncologist if it’s time to switch to an AI. If s/he says no, ask why not, and point to the updated ATAC data.
Bone density: new hope for women taking an aromatase inhibitor:
One of the unfortunate side effects of AI (aromatase inhibitor) hormone therapy is loss of bone density and increased risk of fractures. If you take Femara, Arimidex, or Aromasin, you’re likely to see your bone density drop, often into the risky zone preceding osteoporosis. Now, studies involving two drugs have shown that both promote increased bone density in hormone-receptive, post-menopausal women taking an AI for treatment of early-stage breast cancer.
•Denosumab is given as a twice-yearly injection. A phase III clinical trial showed that women taking denosumab for 2 years showed overall higher bone density than women in the control group, who were given a placebo.
•Zometa (zoledronic acid) is a drug currently prescribed for bone metastases in advanced cancer. Now, it appears to be helpful for increasing bone density, as well. Women who began taking an AI and Zometa concurrently experienced a 7% positive difference in bone density, after 36 months, compared to women taking an AI who began taking Zometa only after they started experiencing bone-density issues.
Bottom line: If you take an AI and your DexaScan shows decreasing bone density, this is worth at least mentioning to your oncologist.
Ocontype DX™ continues to move into the mainstream:
Trying to decide whether to do chemo? The doctor has said it’s up to you? What a decision!
For women with node-negative, ER-receptive breast cancer, there’s been an effective genetic test available for several years. Oncotype DX™ evaluates 21 different genes from your tumor and then assigns you a “risk score”: low, medium, or high. These risk scores have been shown to equate very clearly to actual recurrence risk.
Now, it appears women with node-positive, ER-receptive breast cancer can benefit from the Oncotype DX™ test as well. Women in this group who were tested and assigned a “low” score saw an improvement in risk recurrence of just 4%, from 60% to 64%, when they added chemotherapy to their tamoxifen regimen. Women at “high” risk, on the other hand, saw a significant improvement (12%) in 10-year disease-free survival, from 43% to 55%, by adding chemo to tamoxifen.
Bottom line? If you’re waffling over whether to go through chemo, ask your doctor about Oncotype DX™. Or MammaPrint, a similar test with similar rates of success.
Published On: March 02, 2008