Lobular histology does not predict the need for axillary dissection among ACOSOG Z0011-eligible breast cancers Journal Article

Authors: Mamtani, A.; Zabor, E. C.; Stempel, M.; Morrow, M.
Article Title: Lobular histology does not predict the need for axillary dissection among ACOSOG Z0011-eligible breast cancers
Abstract: Background The American College of Surgeons Oncology Group (ACOSOG) Z0011 trial demonstrated that axillary lymph node dissection (ALND) may be omitted for women with two or fewer positive sentinel nodes (SLNs) undergoing breast-conservation therapy (BCT). Lobular histology comprises a minority of patients, and applicability to these discohesive cancers has been questioned. Methods From August 2010 to March 2017, patients undergoing BCT for cT1-2N0 cancer with positive SLNs were prospectively managed with ALND for three or more positive SLNs or gross extracapsular extension (ECE). In this study, clinicopathologic characteristics and nodal burden were compared between pure/mixed invasive lobular cancer (ILC) and invasive ductal cancer (IDC) patients. Results Among 813 consecutive patients, 104 (12.8%) had ILC and 709 (87.2%) had IDC. ILC was more often multifocal and low grade, and less frequently had lymphovascular invasion (all p < 0.001). ILC more often had SLN macrometastases (81.7% ILC vs. 69.4% IDC; p = 0.01) and more than 2 mm of ECE (30.8% ILC vs. 19.5% IDC; p = 0.03), but the proportions of cases with three or more positive SLNs were similar in the two groups (14.4% ILC vs. 9.9% IDC; p = 0.2). The ALND procedure was performed for 20 ILC patients (19.2%) compared with 97 IDC patients (13.7%) (p = 0.2). Additional positive nodes were found in 80% of the ILC patients versus 56.7% of the IDC patients (p = 0.09). The ALND and nodal burden rates were similar in the estrogen receptor-positive (ER+) subset analysis. In the multivariable analysis, lobular histology (p = 0.03) and larger tumors (p = 0.03) were associated with additional positive nodes. During a median follow-up period of 42 months, there were no isolated axillary recurrences. Conclusions Despite a higher proportion of SLN macrometastases and association with more positive nodes at ALND, lobular histology does not predict the need for ALND. ALND is not indicated on the basis of histology among patients otherwise meeting Z0011 criteria.
Keywords: recurrence; biopsy; metastases; sentinel lymph-node; multicenter; lymphovascular invasion; isolated tumor-cells; american-college; likelihood; negative patients
Journal Title: Annals of Surgical Oncology
Volume: 26
Issue: 10
ISSN: 1068-9265
Publisher: Springer  
Date Published: 2019-10-01
Start Page: 3269
End Page: 3274
Language: English
ACCESSION: WOS:000484928300033
DOI: 10.1245/s10434-019-07536-z
PMCID: PMC6669889
PUBMED: 31342363
Notes: Source: Wos
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MSK Authors
  1. Monica Morrow
    477 Morrow
  2. Emily Craig Zabor
    147 Zabor
  3. Michelle Moccio Stempel
    144 Stempel
  4. Anita   Mamtani
    20 Mamtani