Abstract GS5-02: Axillary dissection vs. no axillary dissection in patients with cT1-T2cN0M0 breast cancer and only micrometastases in the sentinel node(s): Ten-year results of the IBCSG 23-01 trial

Abstract

BACKGROUND: The phase III IBCSG 23-01 multicenter, randomized, non-inferiority trial compared disease-free survival (DFS) in breast cancer patients with one or more micrometastatic (≤2 mm) sentinel nodes (SNs) randomized to either axillary dissection (AD) or no axillary dissection (no-AD). Results after 5 years showed no difference in DFS between the arms. Here we report results after a median follow-up of 9.8 years. METHODS: Eligible patients had cancers of pathological diameter ≤5 cm and one or more micrometastatic (≤2 mm) foci, including isolated tumor cells, in the SNs. Patients with axillary macrometastases were excluded. Breast surgery was conservative or mastectomy. Eligible patients were randomized to AD vs. no-AD. The primary endpoint was disease-free survival (DFS); secondary endpoints were overall survival (OS), site of recurrence (particularly axillary recurrence), and surgical complications of AD. DFS and OS were estimated using the product-limit method, and the log-rank test was used to compare the treatment groups. Patients without a DFS or OS event were censored at the date of last follow-up. Non-inferiority margin for no-AD vs. AD was defined as a DFS hazard ratio (HR, no-AD relative to AD) of <1.25, and was assessed using a z-test applied to the log HR. Active follow-up of patients was terminated in February 2017. RESULTS: From 2001 to 2010, 934 patients were randomized at 27 centers; 931 were evaluable (467 in the no-AD group and 464 in the AD group). Median follow-up was 9.8 (IQR: 7.8–12.7) years. The number and types of first DFS events according to treatment group are shown in the Table. Disease-free Survival EventsNo-ADADTotal101117Breast cancer related events7475Local1413Contralateral breast1012Regional [ipsilateral axillary events]9 [8]3 [2]Distant4147Non-breast cancer related events2742Second malignancies1723Death without prior cancer event62Death with unknown cancer status417 10-year DFS was 75% (95% confidence interval [CI]: 72%–81%) in the no-AD group and 75% (95% CI: 71%–79%) in the AD group (HR [no-AD vs. AD]=0.85; 95% CI: 0.65–1.11; log-rank p=0.23; non-inferiority p=0.002). There were 45 deaths in the no-AD group and 58 in the AD group. 10-year OS was 91% (95% CI: 88%–94%) in the no-AD group and 88% (95% CI: 85%–92%) in the AD group (HR [no-AD vs. AD]=0.77; 95% CI: 0.56–1.07; log-rank p=0.19). CONCLUSION: Findings after a median follow-up of 9.8 years fully support the findings at 5 years in that no-AD is not inferior to AD with respect to DFS, and there is no significant difference between the arms for DFS and OS, thus confirming that AD is not indicated in patients with micrometastatic SNs. Citation Format: Galimberti V, Cole BF, Viale G, Veronesi P, Vicini E, Intra M, Mazzarol G, Massarut S, Zgajnar J, Taffurelli M, Littlejohn D, Egli T, Tondini C, Di Leo A, Colleoni M, Regan MM, Coates AS, Gelber RD, Goldhirsch A. Axillary dissection vs. no axillary dissection in patients with cT1-T2cN0M0 breast cancer and only micrometastases in the sentinel node(s): Ten-year results of the IBCSG 23-01 trial [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS5-02.

Indications for Interventional Procedures of the Breasts and Axillae

“…odsutnost metastaza u regionalnim limfnim čvorovima, nikakav dodatni postupak u pazušnoj jami nije potreban. Čak i u slučajevima kada je u čvoru sentinelu detektirana metastatska bolest (do dvije makrometastaze), aksilarnu limfadenektomiju moguće je izostaviti bez posljedica na onkološke ishode, pod uvjetom da metastaza ne probija kapsulu limfnog čvora i da se adjuvantno provede radioterapija na preostalim limfnim čvorovima [29][30][31] .…”

Overall survival and disease control rates for operable invasive breast cancer in the era of conservative surgery; retrospective, institutional, and five-year follow-up data

“…In addition, two ongoing randomized controlled trials, NEONOD II (13) and ATNEC (14), are yet another step ahead and are currently investigating if cN1 patients, converted to ypN+ following NAT, but with minimal residual disease in the axilla, could be safely spared of ALND with or without radiotherapy to the lymphatic drainage, i.e., investigating if the results of ACOSOG Z010 (6), IBCSG 23-01 (15) and AMAROS (5) trial results can be safely translated into the neoadjuvant setting.…”

Update Breast Cancer 2018 (Part 1) – Primary Breast Cancer and Biomarkers

“…Since the results of the ASOG Z0011 trial, it is generally accepted that pT1c/pT2/cN0 patients who undergo breast-conserving surgery followed by radiotherapy should not undergo secondary axillary lymph node dissection (ALNE), even if a maximum of two sentinel lymph nodes are affected 21 . The IBCSG 23-01 trial, a prospective randomized study, investigated whether it was feasible to dispense with subsequent ALNE in patients with micro-metastasis (≥ 2 mm) in one or more sentinel lymph nodes 22 . After a median follow-up of 9.8 years, no difference was found with regard to disease-free or overall survival.…”

“…Seit den Ergebnissen der ASOG Z0011-Studie sollte bei pT1c/pT2/cN0-Patientinnen, die eine brusterhaltende Operation mit anschließender Bestrahlung erhalten, auf eine sekundäre Axilladissektion (ALNE) auch dann verzichtet werden, wenn maximal 2 Sentinel-Lymphknoten befallen sind 21 . In der IBCSG 23-01-Studie wurde prospektiv randomisiert untersucht, inwieweit bei Patientinnen mit Mikrometastasen (≥ 2 mm) in einem oder mehreren Sentinel-Lymphknoten auf eine anschließende ALNE verzichtet werden kann 22 . Nach einem mittleren Follow-up von mittlerweile 9,8 Jahren zeigt sich kein Unterschied bez.…”