Omission of Sentinel Lymph Node Biopsy Among Clinically Node-Negative Patients With Early Invasive Breast Cancer
Final Primary Results from the INSEMA Trial
Final Primary Results from the INSEMA Trial
According to results from the INSEMA trial, sentinel lymph node biopsy (SLNB) during breast-conserving surgery for early breast cancer may be omitted for select patients who are clinically node-negative without compromising oncological safety.
These results will be presented by Toralf Reimer, MD, University of Rostock, Germany, at the 2024 San Antonio Breast Cancer Symposium.
The prospective randomized INSEMA trial enrolled patients with early invasive breast cancer with a tumor ≤5 cm who were scheduled for breast conserving surgery, including postoperative whole-breast irradiation. There were 4858 patients included in the per-protocol set who were randomized to either not undergo SLNB (n = 962) or to undergo SLNB (n = 3896). The primary end point was non-inferiority of invasive disease-free survival (iDFS) of patients who did not undergo SLNB to those who did undergo SLNB.
The median follow-up duration was 73.6 months. The number of patients who received adjuvant chemotherapy was significant higher in the SLNB arm (13.2% vs 10.7% in the no SLNB arm). The estimated 5-year iDFS rates were 91.9% in the no SLNB arm and 91.7% in the SLNB arm, establishing non-inferiority with a hazard ratio of 0.91. The estimated 5-year overall survival rates were 98.2% in the no SLNB arm and 96.9% in the SLNB arm.
Study authors concluded this trial “demonstrated that the omission of SLNB in clinically node-negative [breast cancer patients] undergoing [breast conserving surgery] resulted in a statistically significant non-inferior iDFS meeting the primary end point.” They added “this practice-changing concept is suitable for patients presenting with low-grade (G1/G2), hormone receptor-positive/HER2-negative invasive [breast cancer] with tumor size up to 5 cm.”
Source:
Reimer T. No axillary surgery versus axillary sentinel lymph node biopsy in patients with early invasive breast cancer and breast-conserving surgery: Final primary results of the Intergroup-Sentinel-Mamma (INSEMA) trial. Presented at 2024 San Antonio Breast Cancer Symposium. Dec 10-13, 2024; San Antonio, TX.
