Journal of Clinical Pathways. 2017;3(10):22-24.
San Antonio Breast Cancer Symposium
This year marked the 40th anniversary of the San Antonio Breast Cancer Symposium (SABCS), which has been a mainstay meeting in the field of breast cancer since 1977. In that time, it has evolved from a meeting attended mostly by local doctors to a worldwide conference attended by more than 7000 individuals from 90 countries. Research and lectures presented at SABCS influence the treatment of women and men with breast cancer around the world.
The 2017 meeting featured several notable lectures, including the SABCS 40th Anniversary Award Lecture, given by Richard Pazdur, MD, director of the Food and Drug Administration’s Oncology Center of Excellence. Dr Pazdur lectured on the past and future of cancer drug development, with a focus on new treatments that have penetrated the breast cancer treatment armamentarium in recent years.
Five distinguished breast cancer researchers received awards at this year’s meeting. Sir Richard Peto, FRS, University of Oxford (England), received the 2017 William L McGuire Memorial Lecture Award. Alan Ashworth, PhD, FRS, University of California at San Francisco, received the Susan G Komen Brinker Award for Scientific Distinction in Basic Science. Dennis J Slamon, MD, PhD, University of California at Los Angeles, received the Susan G Komen Brinker Award for Scientific Distinction in Clinical Research. Jeffrey Rosen, PhD, Baylor College of Medicine (Houston, TX), received the American Association for Cancer Research (AACR) Distinguished Lectureship in Breast Cancer Research. Nicholas C Turner, PhD, FRCP, Institute for Cancer Research (London, England), received the AACR Outstanding Investigator Award for Breast Cancer Research.
Brain Metastasis Commonly Seen in Women With HER2-Positive, Triple-Negative Breast Cancer
Women with human epidermal growth factor receptor 2 (HER2)-positive and triple-negative breast cancer have an elevated risk of developing brain metastasis regardless of active systemic treatment receipt.
Researchers have observed an increased incidence of brain metastasis among patients with breast cancer, but their development patterns following neoadjuvant therapy remains unclear.
Isabell Witzel, MD, University Medical Center Hamburg (Germany), and colleagues analyzed patients in the Geparquinto and Geparsixto trials, which studied women receiving neoadjuvant regimens, in order to observe trends in brain metastasis development. The two trials had a combined patient population of 3160 patients.
The Geparquinto trial assigned women with HER2-positive breast cancer to lapatinib or trastuzumab, while women with HER2-negative breast cancer receivied bevacizumab, along with anthracycline- and taxane-containing regimens. Women who did not respond to these regimens were switched to paclitaxel and everolimus.
The Geparsixto trial assigned women with HER2-positive tumors to trastuzumab and lapatinib, and women with triple-negative tumors to bevacizumab and chemotherapy.
The study had a median follow-up of 61 months. The researchers observed that 3% of patients (n = 108) developed brain metastasis as their first site of recurrence and 13% (n = 411) developed other distant metastases. Patients who developed brain metastasis as their first site of recurrence had a higher rate of relapse-free survival (3-year rate, 96.7% vs 89.5%).
Four percent of patients with HER2-positive breast cancer (n = 34 of 809) and 6% of patients with triple-negative tumors (n = 56 of 1008) developed brain metastasis as first site of recurrence compared with women with luminal A (1%; n = 11 of 954) or luminal B (2%; n = 7 of 381) tumors.
Multivariate analyses identified several risk factors for brain metastasis, including larger tumors (P = .0022), node-positive disease (P < .0001), lack of pathologic complete response after neoadjuvant therapy (P = .0003), and HER2-positive (P = .0002) or triple-negative (P < .0001) subtypes.
According to Dr Witzel and colleagues, breast cancer subtype remained the most relevant predictive factor for brain metastasis.
“Patients who developed brain metastasis were more often HER2-positive or triple-negative compared with patients who developed metastases outside the brain,” they said. “A better understanding of the underlying mechanisms is required in order to develop potential preventive strategies.”