Researchers announced findings from breast cancer studies during Saturday’s sessions of the 50th Annual Meeting of the American Society of Clinical Oncology, in Chicago. These studies represent just a few of those being presented from May 30 to June 3 to the estimated 33,000 attendees.
Obesity and Risk for Recurrence in Younger Women
The risk of dying from breast cancer is significantly higher in obese pre- and perimenopausal women with estrogen-receptor positive early disease than in women of other weights, according to findings from an analysis involving 80,000 women. The researchers, led by Hongchao Pan, PhD, at the University of Oxford in England, defined obesity as a Body Mass Index of at least 30.
When compared with their non-obese counterparts, younger obese women had a 34 percent higher risk of dying from breast cancer. As an example of what that means, obesity could change a 10-year breast cancer death risk of 15 percent into a 10-year risk of 20 percent for pre- and perimenopausal women with ER-positive disease.
Researchers were surprised to learn that this higher risk was not found in obese postmenopausal women with ER-positive disease. They had expected obesity to be more of a risk factor after menopause, Dr. Pan said.
In a late-breaking abstract from a phase III clinical trial, POEMS (Prevention of EarlyMenopause Study), Halle Moore, MD, a staff physician at the Cleveland Clinic, said results indicate that adding a hormone-suppressing medicine called goserelin (Zoladex) to standard chemotherapy may work to preserve fertility among women with early-stage hormone-receptor negative breast cancer.
Women who received goserelin in the study, along with chemotherapy, were 64 percent less likely to lose ovarian function early compared to women who received only chemotherapy. Those who received goserelin also were more likely to have successful pregnancies.
Ovarian failure is a possible side effect of chemotherapy and is defined in this study as not having a menstrual period for 6 months and having postmenopausal levels of follicle-stimulating hormone (FSH). Risk of ovarian failure depends on the kind of chemotherapy and the amount, as well as age and possibly the timing of the menstrual cycle (when during the month the eggs develop in the ovaries) at the time of chemotherapy.
While these early results are encouraging, Dr. Moore cautioned that more research is needed. Women who received goserelin in the study were also 50 percent more likely to be alive 4 years after starting chemotherapy compared to those who received standard treatment.
Avastin in Breast Cancer
Kathy Miller, MD, of Indiana University, reported results from a phase III trial that added bevacizumab (Avastin) to an anthracycline and taxane-based therapy for women with early-stage HER2-negative disease at high risk for recurrence.
Previous trials in metastatic breast cancer have shown that adding bevacizumab improves progression-free survival, or time cancer does not grow, but does not increase breast cancer-free survival or overall survival. Compared to those who took the standard treatment, participants in this trial also did not have longer breast cancer- or overall survival. Those who received the bevacizumab combination also were more likely to develop serious side effects, including high blood pressure, thrombosis (blood clot inside a blood vessel) and hemorrhage.
In another phase III trial, Olivier Tredan, MD, PhD, of Centre Leon Berard in Lyon, France, found that combining paclitaxel (Taxol) and bevacizumab improved progression-free survival in metastatic breast cancer. But bevacizumab was linked with side effects including neuropathy (nerve damage) and fatigue, which worsened over time. Enrollment was stopped from lack of results and for safety concerns.
Because of the high rate of people who stop participation in these trials, Dr. Miller said, further trials of bevacizumab “were unlikely to be fruitful” in breast cancer.
Look for more ASCO updates from Living Beyond Breast Cancer throughout the meeting and in the coming weeks on lbbc.org, and sign up for our free webinar, from noon to 1 p.m. on Tuesday, June 24.