Breast Cancer Research: News from the 2011 SABCS
State-of-the-art information centering on breast cancer research was delivered last week at the San Antonio Breast Cancer Symposium (SABCS), held annually in Texas. Over 9,000 healthcare professionals from 90 countries gathered for a series of presentations, exhibits, and papers reviewing the very latest in research. Following are some of the conference’s highlights.
Predicting recurrence: how accurate can we be?
Apparently, more accurate than ever before. Scientists are developing new types of genetic testing that will someday be able to provide a woman with her own personalized recurrence risk, rather than one simply built on data built from large groups of women with similar diagnoses.
One study examined a multi-gene test that can predict the aggressiveness of DCIS, and how likely it is to recur. Women with a low risk of recurrence could choose to be treated with simple breast conservation surgery (lumpectomy), rather than the current standard of surgery and radiation. Since radiation poses risks of peripheral damage and lasting side effects, it’s best to avoid it when possible.
Another study examined risk of recurrence in women with hormone-positive invasive breast cancer, and discovered a group of genes that would help doctors predict whether a woman will have an early recurrence; a recurrence many years later, or no recurrence at all.
Having this information right at the outset would allow a woman and her doctor to refine treatment choices significantly. With the likelihood of no recurrence, a woman might choose to forego chemotherapy. With recurrence unlikely immediately, but perhaps further down the road, a woman might choose to extend hormone therapy beyond the usual 5 to 10 years.
And if tests show a woman’s cancer is likely to recur within the first few years after diagnosis, she might choose to step up her immediate treatment: choosing chemotherapy, for instance, even if it wouldn’t usually be indicated.
Future hope for women with metastatic cancer
Three studies examined drugs that may extend progression-free survival times for women with metastatic breast cancer.
Women with HER2+ breast cancer are routinely treated with Herceptin and Taxotere. But if their cancer metastasizes, they often develop a resistance to Herceptin; and researchers have been studying other drugs that might replace Herceptin, or increase its waning effectiveness.
One study added pertuzumab (Omnitarg) to Herceptin and Taxotere, and showed a reduction in risk for progression of 38% - in real terms, about 6.1 months. Translation: women in the study taking pertuzumab saw their cancer stay in remission 6.1 months longer than women who took a placebo.
Another study added Avastin to the Herceptin/Taxotere protocol, which showed 28% improvement in risk for progression (about 2.9 months). This is interesting, because the FDA recently removed Avastin from its list of approved breast cancer drugs due to its effectiveness being “statistically insignificant.” Researchers presenting at SABCS argued that their results (28% improvement vs. data the FDA used, showing 18% improvement) was indeed statistically significant.
Finally, a new drug – everolimus (Afinitor, Zortress) – used in combination with the aromatase inhibitor Aromasin showed promise for post-menopausal women with hormone-receptive metastatic cancer. Women treated with the new protocol enjoyed an average of 7.4 months of progression-free survival, compared to 3.2 months for women treated with Aromasin and a placebo.
Obesity and breast cancer: strong links
Several studies added to the growing body of evidence showing a link between obesity and breast cancer.
One study showed a 55% increase in breast cancer in obese women over age 60, compared to normal-weight, 60+ women.
A second study reported that overall, obese women diagnosed with breast cancer are more likely to have a recurrence; more likely to have a recurrence more quickly, and more likely to die from breast cancer.
In addition, obese women don’t respond as well to chemotherapy; and, if they receive neither chemo nor hormone therapy, their survival times are worse than those of normal-weight women undergoing identical treatments.
Another study showed that when obese women with HER2+ cancer are treated with Herceptin concurrent with chemotherapy, their positive response (disease-free survival) is equal to that of normal-weight women undergoing the same treatment. So, at least in one case, being obese (classified as body mass index of 30 or greater) doesn’t hurt your chance of survival.
Osteoporosis drug may help with breast cancer
Two studies focused on zoledronic acid (Reclast, Zometa), a bisphosphonate typically given to treat osteoporosis, as a possible weapon against breast cancer recurrence.
Women with early-stage (non-metastatic), hormone-receptive breast cancer – both pre- and post-menopausal – showed reduced risk of recurrence if they took Reclast or Zometa along with hormone therapy (tamoxifen, or an aromatase inhibitor). Depending on the age of the woman, the reduction ranged from 28% to 34%.
In addition, the drugs also resulted in improved bone mineral density, as would be expected.
While promising, these results don’t mean you should call your doctor tomorrow and ask to be put on Reclast. Zoledronic acid comes with significant side effects, and more study is needed to determine the balance between risk and benefit.
Two studies focused on intake of carbohydrates (particularly starch) and their relation to breast cancer.
In one, women who increased their consumption of starch over the course of the year following their diagnosis were 50% more likely to undergo a recurrence than women who decreased their starch intake. The main source of starch in our diets is potatoes, corn, rice, wheat, and products made from them; clearly, it’s not easy to avoid starch entirely.
But if you’d like to cut back on carbohydrates in general, another study found that an intermittent low-carb diet may be more successful in preventing recurrence, indirectly, than a full-time, stricter diet.
Researchers presented data showing that women who avoided carbs just 2 days per week showed greater weight loss and lowered insulin levels compared to women following the standard Mediterranean diet, which focuses on fresh fruits and vegetables, nuts, olive oil, small amounts of dairy and meat, and a minimum of unrefined carbs (whole grains). Losing weight and lowering insulin have both been tied to a reduction in breast cancer recurrence.
Breast reconstruction: still underutilized
Despite research showing that there are positive benefits for women who opt for an immediate breast reconstruction after mastectomy (compared to those who don’t), fewer than half of women undergoing mastectomy also have immediate reconstruction.
Previous studies have shown a link between breast reconstruction and positive quality of life; a woman’s self esteem, and satisfaction with her body image.
Still, only 22.6% of women who might have reconstruction are getting it. The rate is even lower for women over 50.
Researchers found women are more likely to undergo reconstruction if they have health insurance; are younger; are treated at a suburban or urban hospital, and/or a teaching hospital; and are otherwise healthy. Not surprisingly, health insurance is the single largest factor whether or not a woman has reconstruction.