Neoadjuvant Chemotherapy in Breast Cancer

Neoadjuvant chemotherapy:
- Does not prolong survival compared to adjuvant chemotherapy:
  - However, it does result in decreased disease burden, and can be beneficial at time of surgery:
    - Providing increased opportunity to perform breast-conserving surgery and reducing need for axillary lymph node dissection
A meta-analysis of 14 prospective randomized trials of neoadjuvant vs. adjuvant chemotherapy:
- In 5,500 patients with breast cancer demonstrated that:
  - NAC was associated with an absolute decrease in the mastectomy rate of 16.6% (95% CI 15.1–18.1%)
  - Patients with ER– and HER2 positive breast cancers:
    - Are more likely to experience complete pathologic response than those with ER+ cancers
Patients with a clinically positive axilla after neoadjuvant chemotherapy:
- Should undergo axillary dissection at the time of breast surgery
Patients with no residual adenopathy on clinical exam:
- May be considered for sentinel lymph node biopsy (SLNB):
  - Accuracy of SLNB after NAC can be improved with:
    - Localization of previously-clipped nodes
    - Use of dual tracer
    - Increasing the number of sentinel nodes retrieved:
      - SLNB after NAC has a false-negative rate of less than 10% only when ≥ 3 sentinel nodes were identified
References
- Mieog, JS, van der Hage JA, van de Velde CJ. Neoadjuvant chemotherapy for operable breast cancer. Br J Surg. 2007;94(1):1189-1200.
- van der Hage JA, van de Velde CJH, Julien JP, Tubiana-Hulin M, Vandervelden C, Duchateau L. Preoperative chemotherapy in primary operable breast cancer: results from the European Organization for Research and Treatment of Cancer trial 10902. J Clin Oncol. 2001;19(22):4224-4237.
- Fisher B, Brown A, Mamounas E, et al. Effect of preoperative chemotherapy on local-regional disease in women with operable breast cancer: findings from National Surgical Adjuvant Breast and Bowel Project B-18. J Clin Oncol. 1997;15(7):2483-2493.
- Rouzier R, Perou CM, Symmans WF, et al. Breast cancer molecular subtypes respond differently to preoperative chemotherapy. Clin Cancer Res. 2005;11(16):5678-5685.
- 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 node-positive breast cancer (T0-T4, N1-N2) who receive neoadjuvant chemotherapy: results from ACOSOG Z1071 (Alliance). Ann Surg. 2016;263(4):802-807.
- Boileau, JF, Poirier B, Basik M, et al. Sentinel node biopsy after neoadjuvant chemotherapy in biopsy-proven node-positive breast cancer: the SN FNAC study. J Clin Oncol. 2015;33(3):258-264.