International Breast Cancer Study Group (IBCSG) Study 23

19 October 2018


To answer the question of appropriate management for women who have micrometastases (very tiny/microscopic deposits (< 2mm) of cancer spread) found in the sentinel nodes. This research aims to answer the question of whether these women require axillary clearance or is it safe to manage these women without further surgery?

Scientific Title

IBCSG 23-01: A randomised trial of axillary dissection versus no axillary dissection for patients with clinically node negative breast cancer and micrometastases (< 2mm) in the sentinel node.


Breast surgical oncologists have rapidly and successfully transitioned from the routine use of axillary lymph node dissection (ALND) to sentinel lymph node (SLN) biopsy for staging the axilla in clinically node negative patients. This approach limits the use of ALND to those patients with pathologically-proven axillary lymph node metastases and has prompted great current interest in whether or not all SLN-positive patients benefit from a completion ALND. Analysis of population-based data shows a decades-long trend towards omitting ALND in patients with low volume axillary disease.  For selected patients, mainly those with small, estrogen receptor-positive tumors with low nodal disease burden undergoing breast conservation with radiation and adjuvant systemic therapy, ALND might be avoided safely.


The findings of the IBCSG 23-01 trial after a median follow-up of 9·7 years support the practice of not doing an axillary dissection when the tumour burden in the sentinel nodes is minimal or moderate in patients with early breast cancer. The results showed no difference in disease-free survival between no ALND and ALND.


Axillary dissection versus no axillary dissection in patients with sentinel-node micrometastases (IBCSG 23-01): a phase 3 randomised controlled trial

Galimberti V, Cole BF, Viale G, Veronesi P, Vicini E, Intra M, Mazzarol G, Massarut S, Zgajnar J, Taffurelli M, Littlejohn D, Knauer M, Tondini C, Di Leo A, Colleoni M, Regan MM, Coates AS, Gelber RD, Goldhirsch A; International Breast Cancer Study Group Trial 23-01 investigators. Lancet Oncology; 19 October 2018; 10: 1385-1393.