Positive margins, fibroproliferation in the surrounding breast tissue, and necrosis are associated with a marked increase in LR rates. Efforts should be made to achieve negative surgical margins to reduce risk of LR. Death from PT is rare (2%), and only PT that demonstrate uniformly aggressive pathologic features seem to be associated with mortality.

Background In breast cancer patients with nodal metastases at presentation, false-negative rates <10% have been demonstrated for sentinel node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) when ≥3 negative sentinel nodes (SLNs) are retrieved, but the frequency with which axillary dissection (ALND) can be avoided is uncertain. Methods Among 534 prospectively identified consecutive patients with clinical stage II–III cancer receiving NAC from 11/2013–11/2015, all biopsy-proven node-positive (N+) cases were identified. Patients who were clinically node-negative post-NAC were SLNB-eligible. ALND was indicated for failed mapping, <3 SLNs retrieved, or positive SLNs. Results Of 288 N+ patients, 195 completed surgery. 132/195 (68%) were SLNB-eligible. Of these, median age was 50yrs, 73(55%) were ER+, 21(16%) ER−/HER2+, 38(29%) triple negative. SLNB was deferred intraoperatively in 4 cases. Among 128 SLNB attempts, ≥3 SLNs were retrieved in 110 (86%), 1–2 SLNs in 15(12%), 3 (2%) failed mapping. ALND was indicated in 66 cases: 54(82%) for positive SLNs, 9(14%) for <3 negative SLNs, 3(4%) for failed mapping. 17% with <3 negative SLNs retrieved had persistent disease. 62/128 (48%) had SLNB alone with ≥3 SLNs retrieved. Among 195 N+ patients completing surgery, nodal pathologic complete response (pCR) was achieved in 49%, ranging from 21% in ER+/HER2− to 97% in ER−/HER2+ cases, and was significantly more common than breast pCR in ER+/HER2− and triple-negative cases. Conclusions Nearly 70% of N+ patients were SLNB-eligible post-NAC. ALND was avoided in 48%, supporting the role of NAC in reducing the need for ALND among patients presenting with nodal metastases.

Objective To determine rates of axillary dissection (ALND) and nodal recurrence in patients eligible for ACOSOG Z0011. Summary Background Data Z0011 demonstrated that patients with cT1-2N0 breast cancers and 1–2 involved sentinel lymph nodes (SLNs) having breast-conserving therapy (BCT) had no difference in locoregional recurrence or survival after SLN biopsy alone or ALND. The generalizability of the results and importance of nodal radiotherapy (RT) is unclear. Methods Patients eligible for Z0011had SLN biopsy alone. Prospectively defined indications for ALND were metastases in ≥3 SLNs or gross extracapsular extension. Axillary imaging was not routine. SLN and ALND groups and radiation fields were compared with chi-square and t-tests. Cumulative incidence of recurrences was estimated with competing risk analysis. Results From 8/2010–12/2016, 793 patients met Z0011 eligibility criteria and had SLN metastases. 130 (16%) had ALND; ALND did not vary based on age, estrogen receptor, progesterone receptor, or HER2 status. 5-year event-free survival after SLN alone is 93% with no isolated axillary recurrences. Cumulative 5-year rates of breast+nodal and nodal+distant recurrence were each 0.7%. In 484 SLN-only patients with known RT fields (103 prone, 280 supine tangent, 101 breast+nodes) and follow-up≥12 months, the 5-year cumulative nodal recurrence rate was 1% and did not differ significantly by RT fields. Conclusions We confirm that even without preoperative axillary imaging or routine use of nodal RT, ALND can be avoided in a large majority of Z0011-eligible patients with excellent regional control. This approach has the potential to spare substantial numbers of women the morbidity of ALND.

Low-volume SLN disease after NAC is not an indicator of a low risk of additional positive axillary nodes and remains an indication for ALND, even when not detected on intraoperative FS.

Background In the setting where determining extent of residual disease is key for surgical planning after neoadjuvant chemotherapy (NAC), herein we evaluate reliability of MRI in predicting pathologic complete response (pCR) of the breast primary and axillary nodes following NAC. Study Design Patients who had MRI before and after NAC between 06/2014–08/2015 were identified in a prospective database following IRB approval. Post NAC-MRI of the breast and axillary nodes was correlated with residual disease on final pathology. PCR was defined as absence of invasive and in situ disease. Results We analyzed 129 breast cancers. Median patient age was 50.8 years (range 27.2–80.6). Tumors were HER2 amplified in 52/129 (40%), estrogen receptor-positive/HER2-negative in 46/129 (36%) and triple negative in 31/129 (24%), with respective pCR rates of 50%, 11% and 29%. Median tumor size pre- and post-NAC MRI were 4.1cm and 1.45cm, respectively. MRI had a positive predictive value of 63.4% (26/41) and negative predictive value of 84.1% (74/88) for in-breast pCR. Axillary nodes were abnormal on pre-NAC MRI in 97 cases; 65 had biopsy-confirmed metastases. The nodes normalized on post-NAC MRI in 33/65 (51%); axillary pCR was present in 22/33 (67%). In 32 patients with proven nodal metastases and abnormal nodes on post-NAC MRI, 11 achieved axillary pCR. In 32 patients with normal nodes on pre- and post-NAC MRI, 6 (19%) had metastasis on final pathology. Conclusions Radiologic complete response by MRI does not predict pCR with adequate accuracy to replace pathologic evaluation of the breast tumor and axillary nodes.