Study Urges Against Lymph Node Dissection for Abemaciclib in ER-Positive Breast Cancer

The research published in the journal The Lancet Oncology has revealed that complete axillary lymph node dissection (cALND) to determine the indication for abemaciclib (to avoid cancer recurrence over a five-year period) is linked with severe arm morbidity and should not be recommended for this purpose.

Abemaciclib is an adjuvant CDK4/6 inhibitor to prevent cancer recurrence after initial treatment. cALND is the only prognostic tool available that can detect four or more nodal metastases (pN2–3), which is the only situation where adjuvant abemaciclib is recommended in this case. Alternatively, this procedure could pose significant arm problems for patients.

Against the above background, Prof Jana de Boniface, breast Center, Capio St Goran’s Hospital, Stockholm, Sweden, and colleagues aimed to practically assess the possible benefits and risks of this approach for individual patients participating in the ongoing SENOMAC trial.

For this purpose, 2766 patients were enrolled between Jan 31, 2015, and Dec 31, 2021, for a randomised, phase 3, SENOMAC trial. Patients aged 18 years or older, regardless of performance status, who had clinically node-negative T1–T3 breast cancer with one or two sentinel node macrometastases, were recruited from 67 sites across five European countries. These patients were randomly assigned in a 1:1 ratio using permuted block randomization.

The study reveals that:

• 1705 (67%) is found eligible for this post-hoc study, in which 802 (47%) had a cALND and 903 (53%) had a sentinel lymph node biopsy only.
• Median age was 62 years (IQR 52–71), 1699 (>99%) of 1705 patients were female, and six (<1%) were male.
• 1342 patients responded to questionnaires, after a follow-up of 45·2 months, reported severe or very severe impairment of physical arm function was reported in 84 (13%) of 634 patients who had cALND versus 30 (4%) of 708 who had sentinel lymph node biopsy only.

“cALND poses a significant risk of severe arm complications, and therefore, its use should not be recommended,” researchers concluded.

Reference: de Boniface, J., Appelgren, M., Szulkin, R., Alkner, S., Andersson, Y., Bergkvist, L., Frisell, J., Gentilini, O. D., Kontos, M., Kühn, T., Lundstedt, D., Offersen, B. V., Olofsson Bagge, R., Reimer, T., Sund, M., Christiansen, P., Rydén, L., & Tvedskov, T. F. (2024). Completion axillary lymph node dissection for the identification of pN2–3 status as an indication for adjuvant CDK4/6 inhibitor treatment: A post-hoc analysis of the randomised, phase 3 SENOMAC trial. The Lancet Oncology. Advance online publication. https://doi.org/10.1016/S1470-2045(24)00350-4