(Dallas—March 11, 2022, 10:01 a.m.) –Triple-negative breast cancer (TNBC) accounts for about 10-15% of all breast cancers and these cancers tend to be more common in women younger than age 40, who are Black, or who have a BRCA1 mutation.
The KEYNOTE-522 trial showed improved pathologic complete response and event free-survival in early-stage triple-negative breast cancer patients receiving preoperative pembrolizumab with chemotherapy. But due to potential toxicities with immunotherapy, clinicians are thoughtfully considering how to incorporate pembrolizumab into multi-disciplinary treatment planning.
To explore this issue in greater detail, Elizabeth A. Mittendorf, MD PhD, from Dana-Farber Brigham Cancer Center in Boston developed a study to determine nodal positivity rates in triple-negative breast cancer patients presenting with cT1-2N0 disease. Dr. Mittendorf presented her data at the Society of Surgical Oncology 2022 International Conference on Surgical Care.
Patients with cT1-2N0 triple-negative breast cancer undergoing upfront surgery were identified from the National Cancer Database (2010-2017) and the DFBCC database (Jan 2016- Feb 2021). Pathologic nodal status by clinical T category and clinical tumor size was determined.
Among 45,954 NCDB patients undergoing upfront surgery, 6,363 (13.8%) were pathologically node positive; 5.0% of patients with cT1a/b tumors, 11.6% for cT1c and 19.7% for cT2 tumors. Nodal positivity rates increased with increasing tumor size. Among 343 DFBCC patients undergoing upfront surgery, 50 (14.6%) were pathologically node positive; 9.4% for cT1a/b, 14.9% for cT1c and 20.8% for cT2 tumors.
The nodal positivity rate among cT1-2N0 triple-negative breast cancer patients exceeds 10% for cT1c and larger tumors.
“Pre-treatment axillary US and biopsy can identify these patients and should be considered in patients presenting with TNBC tumors >1cm to inform preoperative immunotherapy considerations,” Dr. Mittendorf said.