Internal Mammary Lymph Node and SNLB After Neoadjuvant Chemotherapy

As reported by Veronesi in 1999,:
- 737 patients were randomized to either undergo:
  - Halsted mastectomy or extended mastectomy with IM node dissection:
    - After 30 years of follow-up, there was no difference in overall survival or disease-specific survival:
      - For the patients eligible with T1, T2, T3, N0, and N1 disease who underwent IM node dissection vs. no IM dissection
A 2019 retrospective review of 95 breast cancer patients with clinically detected IM nodes (IMNs) at diagnosis:
- Were treated with surgery and radiation:
  - With median follow-up of 43 months
- 77 received neoadjuvant chemotherapy:
  - With IMN normalization in 67.5%, and partial IMN response in 24.6%
- The 5-year IMN failure-free survival, disease-free survival, and overall survival were:
  - 96%, 70%, and 84%, respectively
- IMN failure-free survival was significantly affected by:
  - Resection margin status
  - Size of IMN
  - Receipt of IMN boost radiation
A recently published meta-analysis in the Annals of Surgery found that axillary staging following neoadjuvant chemotherapy:
- Is best performed with a combination approach of:
  - Sentinel lymph node biopsy with excision of the pre-chemotherapy-marked positive node:
    - With a false negative rate of 2% to 4%:
      - The identification rate was 100%
  - ACOSOG Z1071 reported an overall false negative rate of 12.6%:
    - When sentinel node biopsy was performed after neoadjuvant chemotherapy with documented node-positive disease prior to treatment
    - The false-negative rate decreased to 6.8%:
      - When both sentinel node(s) and the clipped node were retrieved at the time of surgery
References
- Veronesi U, Marubini E, Mariani L, Valagussa P, Zucali R. The dissection of internal mammary nodes does not improve the survival of breast cancer patients. 30-year results of a randomised trial. Eur J Cancer. 1999;35(9):1320-1325.
- Kim J, Chang JS, Choi SH, et.al. Radiotherapy for initial clinically positive internal mammary nodes in breast cancer. Radiat Oncol J. 2019;37(2):91-100.
- Simons JM, van Nijnatten TJA, van der Pol CC, Luiten EJT, Koppert LB, Smidt ML. Diagnostic accuracy of different surgical procedures for axillary staging after neoadjuvant systemic therapy in node-positive breast cancer: a systematic review and meta-analysis. Ann Surg. 2019;269(3):432-442.
- Boughey JC, Ballman KV, Le-Petross HT, et al. Identification and resection of clipped node decreases the false-negative rate of sentinel lymph node surgery in patients presenting with nodepositive breast cancer (T0-T4, N1-N2) who receive neoadjuvant chemotherapy: results from ACOSOG Z1071 (Alliance). Ann Surg. 2016;263(5):802-807.