[Axillary pathologic response after neoadjuvant chemotherapy in locally advanced breast cancer with axillary...

To compare axillary involvement (N+) at initial staging in locally advanced breast cancer (LABC) with axillary lymphadenectomy histologic results after neoadjuvant chemotherapy treatment (NeoChemo).

Retrospective study between November 2011 and September 2013 of LABC cases treated with neoadjuvant chemotherapy based on docetaxel (associated with trastuzumab in HER2 positive cases and carboplatin/adriamycin in HER2 negative cases). Those clinically or radiologically suspected cases of axillary involvement were histologically confirmed. When there was no suspicion of axillary involvement, sentinel lymph node radioguided biopsy (SLNRB) was performed using intradermal injection of (99m)Tc-nanocolloid albumin prior to neoadjuvant treatment. Axillary lymphadenectomy after NeoChemo was undertaken in all cases with positive axilla. Final pathologic response was classified as complete (pCR) when there was no evidence of tumoral disease and as non-pathologic complete response (no pCR) in the opposite case.

A total of 346 patients treated with docetaxel were reviewed, identifying 105 LABC. Axillary involvement at initial staging was detected in 70 (67%) before starting NeoChemo. From these 70, 73% (n=51) were N+ (fine needle biopsy and/or biopsy) and the remaining 19 (27%) were occult N+ detected by SLNRB. Axillary lymphadenectomy detected pCR in 56% (39/70), increasing up to 84% pCR when initial N+ status was reached using SNLB. On the other hand, when N+ was detected using fine needle biopsy/lymph biopsy, pCR was only 45%.

More than 50% of women affected by locally advanced breast cancer with tumoral axillary involvement at initial diagnosis present free metastatic axilla after therapeutic neoadjuvant chemotherapy effect. This increases up to almost 90% in case of occult metastatic axilla detected with sentinel node biopsy prior starting neoadjuvant chemotherapy.