Breast Cancer Update
Highlights of the 33rd Annual San Antonio Breast Cancer Symposium
The 33rd Annual San Antonio Breast Cancer Symposium, sponsored by The Cancer Therapy & Research Center at The University of Texas Health Science Center at San Antonio, the American Association for Cancer Research, and Baylor College of Medicine, was held December 8-12, 2010. The symposium was designed to provide state-of-the-art information on the experimental biology, etiology, prevention, diagnosis, and therapy of breast cancer and premalignant breast disease, to an international audience of academic and private physicians and researchers. Highlights of the meeting follow.
Aromatase Inhibitors Increased Risk
of Heart Disease in Postmenopausal
Women with Breast Cancer
Postmenopausal women who take aromatase inhibitors as a treatment for breast cancer may be at an increased risk for developing cardiovascular disease, according to the results of a meta-analysis. Data from the analysis confirmed that any duration of use of an aromatase inhibitor was associated with a 20 percent higher probability of developing cardiovascular disease. These data indicate that women with breast cancer who have risk factors for cardiovascular disease should be considered for a shorter duration of use of aromatase inhibitors.
Pertuzumab and Trastuzumab Combination
Improved Efficacy for Women
with HER2-Positive Breast Cancer
The combination of pertuzumab and trastuzumab had superior anti-tumor activity in women with early HER2-positive breast cancer, according to Phase II study results of the NeoSphere neoadjuvant trial. The results showed that combining pertuzumab with trastuzumab might offer improved efficacy to women with early HER2-positive breast cancer. Additionally, a small percentage of tumors could be treated and eventually cured without chemotherapy.
Combination Therapy Reduced
HER2-Positive Breast Cancers
A combination of lapatinib, trastuzumab, and paclitaxel significantly improved tumor response rates than either agent alone among women with HER2-positive breast cancers, according to new data. Lead researcher José Baselga, MD, PhD, chief of the division of Hematology and Oncology and associate director of the Massachusetts General Hospital Cancer Center, said early data indicate a 50 percent rate of pathological complete remission, compared with 20 percent for either agent alone.
“This study suggests that a dual blockade against HER2 is an efficient way to target HER2-positive breast tumors and that lapatinib adds to trastuzumab. While further research is ongoing, our results indicate that we are on the right track to improve the therapy of HER2-positive disease,” said Dr. Baselga.
High CTC Levels Predicted Poor Outcome
in Metastatic Breast Cancer
A high level of circulating tumor cells are an independent prognostic marker in metastatic breast cancer as first-line therapy. In addition, persistence of high CTC level during therapy was found to be an early marker of poor outcome.
Denosumab Delayed Time to First
Skeletal-related Side Effect
For people with breast cancer and bone metastases, denosumab, sold by Amgen as XGEVA®, delayed skeletal-related side effects five months longer compared to those on zoledronic acid, according to study results.
Alison T. Stopeck, MD, associate professor of Medicine and director of the Clinical Breast Cancer Program at the Arizona Cancer Center of the University of Arizona in Tucson thinks these results will be practice changing. “We now have an alternative to zoledronic acid that is more convenient, less toxic, and more effective for patients with bone metastases,” she said.
Unique Needs and Outcomes of
Pregnant Women with Breast
Do not delay treatment of breast cancer just because a woman is pregnant, said lead researcher Sibylle Loibl, MD, of the German Breast Group. This suggestion is based on study results detailing the effects of different treatment options on the infant.
Researchers collected data from 313 women who were pregnant when they were diagnosed with breast cancer. Some women received various treatment regimens while the rest received chemotherapy.
Premature deliveries were more common among those who did not receive chemotherapy than among women who did. In addition, the infants of the women who received chemotherapy tended to weigh a little more than those who did not receive chemotherapy. Infants from both groups experienced congenital problems, mostly related to premature birth.
Based on these results Dr. Loibl said she would advise pregnant women with cancer to “continue the pregnancy and start with a treatment as closely as possible to standard recommendations for non-pregnant women.” In addition, it is critical that a multidisciplinary team in close collaboration with an obstetrician, a prenatal care specialist, and a neonatologist treat the pregnant woman.
Exemestane May Be Another
First-Line, Adjuvant Therapy
for Hormone-Receptor Positive,
Early-Stage Breast Cancer
Exemestane, an aromatase inhibitor that blocks production of estrogen, may provide another post-surgery option for postmenopausal women with hormone-receptor positive, early-stage breast cancer. In this adjuvant clinical trial comparing two aromatase inhibitors, anastrozole and exemestane, the drugs resulted in similar survival rates and prevention of breast cancer recurrences. Some differences in the side effect profile were seen, including a potential difference in the risk of developing osteoporosis.
“We found that the drugs are comparable in terms of preventing recurrent breast cancer and in overall survival,” said Paul E. Goss, MD, PhD, professor of Medicine at Harvard Medical School in Boston, MA. “Osteoporosis was reported less frequently and cholesterol levels appeared to be lower in patients on exemestane than anastrozole. Other side effects, such as mood change and abnormalities of blood tests assessing liver function, were reported more frequently with exemestane, although the overall numbers of these events were small. With these results, exemestane should be considered as an alternative to anastrozole for initial adjuvant therapy.”
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This article was originally published in Coping® with Cancer magazine, January/February 2011.