San Antonio Breast Cancer Symposium

Researchers from the ATAC and BIG 1-98 trials reported that CYP2D6 testing is not ready for prime time for gauging response to tamoxifen. While a leading researcher in the field of CYP2D6 genotyping posed some key questions that need to be answered before CYP2D6 can be officially ruled out, or embraced, in clinical practice, these study results strongly suggest that CYPD2D6 testing should not be part of the standard of care, said Claudine Isaacs, MD.

Ten-year follow-up results from the BCIRG 001 trial make a case for TAC therapy over FAC. In another study, researchers suggested a link between aromatase inhibitor therapy and breast density.

An update of a long-term denosumab (Xgeva) trial offers another bisphosphonate as an alternative to zoledronic acid (Zometa) that is more convenient, less toxic, and more effective in bone metastases. But oncologists need to perform an oral exam of patients with bone metastases before placing them on denosumab.

Results from an observational study strongly indicated that circulating tumor cells (CTCs) are an independent prognostic marker in metastatic breast cancer at first-line chemotherapy, and an early predictive marker of clinical benefit after one cycle of chemotherapy. But questions remain about the value of CTCs for guiding treatment decision-making.

Jose Baselga, MD, PhD, and Michael Untch, MD, shared results from the NeoALLTO and GeparQuinto trials, respectively. NeoALLTO is a phase III, randomized, open-label, neoadjuvant study of lapatinib (Tykerb), trastuzumab (Herceptin), and their combination plus paclitaxel in women with HER2-positive primary breast cancer. GeparQuinto (GBG 44) is evaluating lapatinib vs trastuzumab in combination with neoadjuvant anthracycline- and taxane-based chemotherapy.

The SUCCESS adjuvant therapy trial enrolled 2,026 women with primary breast cancer and no clinical evidence of metastatic disease. Disease-free survival at three years was 88.1% in women with one or more circulating tumor cells (CTCs) in their peripheral blood before undergoing chemotherapy compared with 93.7% in women with no CTCs.

Results from the GINECO group study demonstrate Afinitor’s ability to buy more time for patients while Xgeva makes everyday life less painful.

As the FDA considers whether to rescind approval for bevacizumab (Avastin) in the adjuvant setting, “disappointing” results from the GeparQuinto study indicate the agent may be best reserved for patients with triple-negative disease.

Although there was no benefit for Zoledronic acid overall, the researchers reported significantly improved disease-free survival and overall survival in women who were more than five years postmenopause. Adjuvant bisphosphonate efficacy may be dependent on low estrogen concentration within the bone microenvironment, according to Robert Coleman, MD.

Exemestane provides a new option for upfront, five-year endocrine therapy in postmenopausal women, based on results of the first definitive early breast cancer trial to compare nonsteroidal and steroidal therapy.