As reported in The Lancet Oncology by Pfob et al, a pooled analysis of randomized trials showed that performance of lymph node surgery for the sole purpose of determining eligibility for CDK4/6 inhibitor treatment does not appear to be a promising strategy in patients with early breast cancer.
As stated by the investigators, “Omitting sentinel lymph node biopsy (SLNB) and completion axillary lymph node dissection (cALND) in early-stage breast cancer reduces morbidity without compromising overall survival or recurrence rates. However, reduced axillary surgery restricts staging information, impacting eligibility for CDK4/6 inhibitors. We evaluated the impact of omitting SLNB or cALND on CDK4/6 inhibitor eligibility and the associated benefits and harms.”
Study Details
The study used data from five randomized trials (SOUND, INSEMA, SENOMAC, monarchE, and NATALEE) that evaluated the safety of de-escalated lymph node surgery and adjuvant CDK4/6 inhibitors in patients with early breast cancer. The primary outcome measure of the current analysis was the number needed to diagnose and treat with CDK4/6 inhibitor—ie, number of axillary surgeries leading to adjuvant CDK4/6 inhibitor use to prevent one invasive disease-free survival event, distant disease-free survival event, or overall survival event at 5 years.
Key Findings
The study included 19,541 patients from the five trials. Median follow-up was 57.2 months (interquartile range = 44.1–81.6 months).
For SLNB and ribociclib, the number needed to diagnose and treat for one prevented event at 5 years was 123 for invasive disease-free survival, 129 for distant disease-free survival, and 345 for overall survival.
For cALND and abemaciclib, the number needed to diagnose and treat for one prevented event at 5 years was 106 for invasive disease-free survival, 119 for distant disease-free survival, and 807 for overall survival.
The investigators concluded: “Performing SLNB or cALND solely to determine eligibility for CDK4/6 inhibition requires very high number needed to diagnose and treat, adds substantial morbidity, and is costly, with only marginal overall survival benefit.”
Jörg Heil, MD, of Breast Center Heidelberg, Hospital St Elisabeth & Heidelberg University Hospital, Heidelberg, Germany, is the corresponding author for The Lancet Oncology article.
DISCLOSURE: The investigators reported that there was no external funding for the study. For full disclosures of the study authors, visit thelancet.com.
