{"entity":{"id":"senomac","kind":"trial","name":"SENOMAC","aka":["Sentinel Node Biopsy in Breast Cancer: Omission of Axillary Clearance After Macrometastases"],"tldr":"The trial that closed the argument Z0011 opened. Even when a node holds a deposit bigger than two millimetres, and even after a mastectomy, leaving the rest of the armpit alone was as safe, provided the nodes were treated with radiotherapy.","summary":"SENOMAC was designed against the three criticisms of Z0011: too few patients, no mastectomy patients, and uncertainty about what the radiotherapy fields actually covered. Between January 2015 and December 2021 it enrolled 2,766 patients in five countries with clinically node-negative T1 to T3 breast cancer and one or two sentinel node macrometastases, and randomised them to completion axillary clearance or to sentinel node biopsy alone. The per-protocol population was 2,540. Radiotherapy including nodal target volumes was given to 89.9 percent of the sentinel node-only group and 88.4 percent of the dissection group, and that is recorded rather than assumed.\n\nAt a median 46.8 months, estimated five-year recurrence-free survival was 89.7 percent (95 percent confidence interval 87.5 to 91.9) with sentinel node biopsy alone and 88.7 percent (86.3 to 91.1) with clearance, a country-adjusted hazard ratio for recurrence or death of 0.89 (0.66 to 1.19), significantly below the non-inferiority margin of 1.44 (p<0.001).\n\nWhat SENOMAC does not do is remove the nodal radiotherapy. Nine in ten patients had it, so the trial tests omitting the operation, not omitting treatment of the axilla. POSNOC, which forbids axillary and supraclavicular radiotherapy in its experimental arm, is the trial that tests the stronger claim.","status":"positive","asOf":"2026-09-25","links":[{"label":"ClinicalTrials.gov NCT02240472","url":"https://clinicaltrials.gov/study/NCT02240472"},{"label":"SENOMAC (New England Journal of Medicine 2024)","url":"https://doi.org/10.1056/NEJMoa2313487"}],"tags":[],"related":[],"cancers":["breast-cancer","breast-hr-positive","breast-her2-positive","tnbc"],"sections":[],"technologies":["sentinel-node","imrt-igrt"],"targets":[],"drugs":[],"companies":[],"institutions":["karolinska"],"pathways":[],"terms":["sentinel-lymph-node-biopsy","lymphadenectomy","axillary-surgery-de-escalation","breast-cancer-related-lymphoedema"],"trials":["acosog-z0011","ibcsg-23-01","amaros","posnoc"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"nct":"NCT02240472","phase":"3","setting":"Clinically node-negative T1 to T3 breast cancer with one or two sentinel node macrometastases larger than 2 mm: completion axillary clearance against sentinel node biopsy alone, with overall survival as the primary endpoint and recurrence-free survival reported first, non-inferiority margin 1.44","sponsor":"Karolinska Institutet, with the Swedish Research Council","result":"Five-year recurrence-free survival 89.7 percent with sentinel node biopsy alone against 88.7 percent with completion axillary clearance (hazard ratio 0.89, 0.66 to 1.19, non-inferior).","yearReported":2024,"enrolled":2766,"enrolledBasis":"registry","outcomes":[{"endpoint":"Recurrence-free survival at 5 years","primary":true,"unit":"%","arms":[{"name":"Sentinel node biopsy only","n":1335,"value":89.7,"note":"95 percent confidence interval 87.5 to 91.9"},{"name":"Completion axillary lymph node dissection","n":1205,"value":88.7,"note":"95 percent confidence interval 86.3 to 91.1"}],"hr":0.89,"ci":[0.66,1.19],"p":"<0.001 for non-inferiority","source":"https://doi.org/10.1056/NEJMoa2313487"}],"replication":"Z0011 and IBCSG 23-01 reached the same conclusion in smaller and lower-burden populations; POSNOC is testing whether the nodal radiotherapy can also go."},"route":"/trials/senomac/","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":"imrt-igrt","kind":"technology","name":"IMRT / IGRT (modern external beam)","route":"/technologies/imrt-igrt/"},{"id":"sentinel-node","kind":"technology","name":"Sentinel lymph node biopsy","route":"/technologies/sentinel-node/"}],"institution":[{"id":"karolinska","kind":"institution","name":"Karolinska University Hospital","route":"/institutions/karolinska/"}],"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":"amaros","kind":"trial","name":"AMAROS (EORTC 10981-22023)","route":"/trials/amaros/"},{"id":"ibcsg-23-01","kind":"trial","name":"IBCSG 23-01","route":"/trials/ibcsg-23-01/"},{"id":"posnoc","kind":"trial","name":"POSNOC","route":"/trials/posnoc/"}]}}