Sentinel Lymph Node Biopsy and Axillary Dissection in Early Breast Cancer

Sentinel lymph node biopsy (SLNB) has replaced axillary lymph node dissection (ALND):
- As the primary method of axillary staging for patients with early stage breast cancer
Changes in patient presentation and advancements in systemic therapy:
- Have led clinicians to question the utility of ALND even in the presence of involved nodes
The American College of Surgeons Oncology Group (ACOSOG) Z0011 trial:
- Randomized women with T1 / T2 tumors undergoing breast conservation with one or two positive sentinel nodes to undergo ALND vs. no additional axillary surgery
- Results showed no difference in local recurrence, disease-free survival (DFS), or overall survival (OS) between the groups
  - The authors concluded that ALND was not indicated in this setting
One of the major advantages of SLNB compared to ALND:
- Is the ability to stage the axilla with reduced rates of lymphedema
A recent meta-analysis of five randomized controlled trials (including the Z0011 trial):
- Reported a 70% reduction in risk of lymphedema with SLNB compared to ALND
Multi-gene assays such as the 21-gene recurrence score (RS):
- Have provided prognostic information regarding risk of distant recurrence:
  - For patients with node-negative, ER+ breast cancers
- Although evidence suggests that adding chemotherapy to endocrine therapy does result in improved DFS and OS for node-positive patients:
  - Exploratory data suggest that this may not be true for all patients
- A retrospective analysis of the RS performed on 367 specimens from the SWOG 8814 trial:
  - Showed that RS was prognostic for DFS and OS in node-positive patients
- The National Comprehensive Cancer Network:
  - Allows patients with 1 to 3 positive nodes to consider the 21-gene recurrence score to determine benefit from chemotherapy
References
- Giuliano AE, Ballman K, McCall L, et al. Locoregional recurrence after sentinel lymph node dissection with or without axillary dissection in patients with sentinel lymph node metastases: long-term follow-up from the American College of Surgeons Oncology Group (Alliance) ACOSOG Z0011 randomized trial. Ann Surg. 2016; 264(3):413-420.
- Glechner A, Wockel A, Gartlehner G, et al. Sentinel lymph node dissection only versus complete axillary lymph node dissection in early invasive breast cancer: a systematic review and meta-analysis. Eur J Cancer. 2013;49(4):812-825.
- Albain KS, Barlow WE, Shak S, et al. Prognostic and predictive value of the 21-gene recurrence score assay in postmenopausal women with node-positive, estrogen-receptor-positive breast cancer on chemotherapy: a retrospective analysis of a randomised trial. Lancet Oncol. 2010;11(1):55-65.
- Breast cancer. National Comprehensive Cancer Network. 2018. https://www.nccn.org/professionals/physician_gls/pdf/breast.pdf Accessed September 14, 2018.