{"entity":{"id":"ibcsg-23-01","kind":"trial","name":"IBCSG 23-01","aka":["International Breast Cancer Study Group 23-01","IBCSG 23-01 micrometastasis trial"],"tldr":"A deposit of cancer smaller than two millimetres in a lymph node is not a reason to clear the armpit. Ten years later the women who had nothing further done were doing slightly better, and had a quarter of the arm swelling.","summary":"IBCSG 23-01 recruited from 27 hospitals in nine countries between 2001 and 2010. Eligible women had a breast cancer of 5 cm or less and one or more sentinel nodes containing a micrometastasis of 2 mm or smaller without extracapsular extension, and were randomised before surgery to axillary clearance or none. 934 were randomised and three were later found ineligible.\n\nAt a median follow-up of 9.7 years, ten-year disease-free survival was 76.8 percent without clearance and 74.9 percent with it (hazard ratio 0.85, 95 percent confidence interval 0.65 to 1.11, log-rank p=0.24, non-inferiority p=0.0024). The morbidity difference is the reason to act on it: lymphoedema of any grade occurred in 16 of 453 patients (4 percent) without clearance and 60 of 447 (13 percent) with it, sensory neuropathy in 13 against 19 percent, and motor neuropathy in 3 against 9 percent.\n\nThe ten-year analysis was not pre-specified in the protocol and was not adjusted for repeated testing, which the authors say plainly. Read with Z0011, it is the reason NICE NG101 recommendation 1.4.14 says not to offer further axillary treatment for micrometastases at all.","status":"positive","asOf":"2026-09-25","links":[{"label":"ClinicalTrials.gov NCT00072293","url":"https://clinicaltrials.gov/study/NCT00072293"},{"label":"IBCSG 23-01 ten-year follow-up (Lancet Oncology 2018)","url":"https://doi.org/10.1016/S1470-2045(18)30380-2"}],"tags":[],"related":[],"cancers":["breast-cancer","breast-hr-positive","breast-her2-positive","tnbc"],"sections":[],"technologies":["sentinel-node"],"targets":[],"drugs":[],"companies":["etop-ibcsg"],"institutions":[],"pathways":[],"terms":["sentinel-lymph-node-biopsy","lymphadenectomy","breast-cancer-related-lymphoedema","axillary-surgery-de-escalation"],"trials":["acosog-z0011","senomac"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT00072293","phase":"3","setting":"Breast cancer 5 cm or smaller with one or more sentinel node micrometastases of 2 mm or less and no extracapsular extension, after mastectomy or breast-conserving surgery: axillary clearance against no axillary clearance, with disease-free survival as the primary endpoint and a non-inferiority margin of 1.25","sponsor":"International Breast Cancer Study Group","result":"Ten-year disease-free survival 76.8 percent without axillary clearance against 74.9 percent with it (hazard ratio 0.85); lymphoedema 4 against 13 percent.","yearReported":2018,"enrolled":931,"enrolledBasis":"registry","outcomes":[{"endpoint":"Disease-free survival at 10 years","primary":true,"unit":"%","arms":[{"name":"No axillary dissection","n":469,"value":76.8,"note":"95 percent confidence interval 72.5 to 81.0"},{"name":"Axillary dissection","n":465,"value":74.9,"note":"95 percent confidence interval 70.5 to 79.3"}],"hr":0.85,"ci":[0.65,1.11],"p":"0.24 log-rank, 0.0024 for non-inferiority","source":"https://doi.org/10.1016/S1470-2045(18)30380-2"},{"endpoint":"Lymphoedema of any grade","unit":"%","arms":[{"name":"No axillary dissection","n":453,"value":4},{"name":"Axillary dissection","n":447,"value":13}],"source":"https://doi.org/10.1016/S1470-2045(18)30380-2"}],"replication":"The ten-year Z0011 analysis reached the same conclusion for one or two positive sentinel nodes including macrometastases."},"route":"/trials/ibcsg-23-01/","neighbours":{"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"breast-her2-positive","kind":"cancer","name":"HER2-positive breast cancer","route":"/cancers/breast-her2-positive/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"technology":[{"id":"sentinel-node","kind":"technology","name":"Sentinel lymph node biopsy","route":"/technologies/sentinel-node/"}],"company":[{"id":"etop-ibcsg","kind":"company","name":"ETOP IBCSG Partners Foundation","route":"/companies/etop-ibcsg/"}],"term":[{"id":"axillary-surgery-de-escalation","kind":"term","name":"Doing less to the armpit","route":"/terms/axillary-surgery-de-escalation/"},{"id":"lymphadenectomy","kind":"term","name":"Lymphadenectomy (lymph node dissection)","route":"/terms/lymphadenectomy/"},{"id":"breast-cancer-related-lymphoedema","kind":"term","name":"Lymphoedema after breast cancer treatment","route":"/terms/breast-cancer-related-lymphoedema/"},{"id":"sentinel-lymph-node-biopsy","kind":"term","name":"Sentinel node biopsy","route":"/terms/sentinel-lymph-node-biopsy/"}],"trial":[{"id":"acosog-z0011","kind":"trial","name":"ACOSOG Z0011 (Alliance)","route":"/trials/acosog-z0011/"},{"id":"senomac","kind":"trial","name":"SENOMAC","route":"/trials/senomac/"}]}}