The annual meeting of the San Antonio Breast Cancer Symposium was held from Dec. 8 to 12 in San Antonio and attracted more than 7,500 participants from around the world, including medical oncologists, radiation oncologists, researchers, and other health care professionals. The conference highlighted recent advances in the risk, diagnosis, treatment, and prevention of breast cancer, with presentations focusing on emerging treatments in hard-to-treat patient populations, including patients with metastatic breast cancer.
In one study, Sarat Chandarlapaty, M.D., Ph.D., of the Memorial Sloan Kettering Cancer Center in New York City, and colleagues found that mutations in the estrogen receptor 1 (ESR1) gene are prevalent in metastatic breast cancer and are associated with a worse prognosis.
“The key findings from the study are that by analysis of plasma from patients with estrogen receptor (ER)-positive metastatic breast cancer we find that up to 30 percent of patients have one of the two most common activating mutations. We find these patients have a shorter median overall survival than those without mutation,” Chandarlapaty said. “At this point the impact is greater on the research community. These data impact the types of assays we should be doing for patient identification and the types of drug strategies we ought to be evaluating.”
The study was funded, in part, by Novartis.
In another study, Reuben Harris, Ph.D., of the Howard Hughes Medical Institute and the University of Minnesota Twin Cities in Minneapolis, and colleagues evaluated the link between an anti-viral enzyme, APOBEC3B, and outcomes in breast cancer.
“We retrospectively evaluated a large cohort of breast cancer patients treated with surgical resection who were given tamoxifen when their ER-positive tumors recurred. We evaluated outcomes over time. We then went back into original frozen tumor specimens and sampled them to look at levels of the enzyme and found that high levels of APOBEC3B correlated with poorer outcomes in response to tamoxifen,” Harris said. “Importantly, the median duration of progression-free survival was much shorter if levels of the enzyme were high and longer if levels were low (seven versus 14 months). In essence, the duration of progression-free survival was nearly twice as long in patients whose original tumors had low APOBEC3B levels.”
In the second part of the study, the investigators performed cause and effect experiments using xenografts. They found that depleting levels of endogenous APOBEC3B using specific short hairpin RNA constructs enabled the grafted cell masses to be treated with tamoxifen for far longer periods.
“Taken together, our studies indicate that APOBEC3B is an ongoing source of mutation in ER-positive breast cancer that causes tamoxifen resistance,” Harris added. “It is likely that these findings will apply more generally to other types of breast cancer, as well as other cancers, because APOBEC3B is broadly overexpressed. Other targeted therapies may indeed be failing for the same reason.”
One author disclosed a financial relationship with ApoGen Biotechnologies.
William Sikov, M.D., of the Women and Infants Hospital of Rhode Island and the Warren Alpert Medical School of Brown University in Providence, and colleagues aimed to determine whether adding carboplatin or bevacizumab to a standard chemotherapy regimen in stage II and III triple-negative breast cancer would increase the pathologic complete response rate.
“We found that patients who had achieved a pathologic complete response with study treatment had large improvements in outcomes compared to patients who did not. We saw a 70 percent reduction in recurrences and an 80 percent reduction in deaths, resulting in 20 percent absolute improvements in event-free and overall survival compared to those who did not achieve pathologic complete response,” Sikov said. “While this has been reported in prior studies, we were encouraged to see such excellent outcomes with the substantially higher pathologic complete response rate achieved by patients treated in our trial. We are also pleased that the substantial fraction of patients who had minute residual disease showed outcomes that were just as good as those who achieved a pathologic complete response. While retrospective analyses have suggested this, this is the first time that it has been shown in a prospective manner.”
The study was sponsored, in part, by Genentech, the manufacturer of bevacizumab.
SABCS: Laser Ablation May Be an Alternative Breast Cancer Tx
FRIDAY, Dec. 11, 2015 (HealthDay News) — Laser ablation may be an effective way to treat small breast cancers, potentially eliminating the need for lumpectomy, new research suggests. Study findings on the laser technique were scheduled to be presented at the annual San Antonio Breast Cancer Symposium, held from Dec. 8 to 12 in San Antonio.
SABCS: Tamoxifen, Anastrozole Both Prevent Recurrence in DCIS
FRIDAY, Dec. 11, 2015 (HealthDay News) — Postmenopausal women with hormone receptor-positive ductal carcinoma in situ (DCIS) have similar recurrence rates of disease whether they take tamoxifen or the aromatase inhibitor anastrozole after surgery, according to findings scheduled to be presented at the annual San Antonio Breast Cancer Symposium, held from Dec. 8 to 12 in San Antonio.
SABCS: In Early Breast CA, Breast-Conserving Tx Beats Mastectomy
THURSDAY, Dec. 10, 2015 (HealthDay News) — Women with early-stage breast cancer may survive longer if they opt for lumpectomy followed by radiation, rather than a mastectomy, a new study suggests. The findings were scheduled to be presented at the annual San Antonio Breast Cancer Symposium, held from Dec. 8 to 12 in San Antonio.
SABCS: β-Blockers, ACEIs May Protect Heart During Chemo
WEDNESDAY, Dec. 9, 2015 (HealthDay News) — β-blockers and angiotensin-converting enzyme inhibitors can prevent heart damage in breast cancer patients as they undergo chemotherapy, according to research scheduled to be presented at the annual San Antonio Breast Cancer Symposium, held from Dec. 8 to 12 in San Antonio.
SABCS: Adding Capecitabine Ups Outcomes for Breast CA Patients
WEDNESDAY, Dec. 9, 2015 (HealthDay News) — Capecitabine appears to reduce risk of recurrence for breast cancer patients with residual disease after presurgery chemotherapy, according to research presented at the annual San Antonio Breast Cancer Symposium, held from Dec. 8 to 12 in San Antonio. In addition, denosumab appears to reduce recurrence risk in women who have hormone receptor (HR)-positive breast cancer, a second study reports.
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