Is sentinel lymph node biopsy reliable and indicated after preoperative chemotherapy in patients with breast carcinoma?

BACKGROUND Many studies support the concept and accuracy of sentinel lymph node biopsy (SNB) for staging patients with breast carcinoma, which can be performed with low morbidity in lymph node negative patients. Preoperative chemotherapy (PC) plays an important role in the treatment of patients with operable breast carcinoma and is another approach with which to reduce radical surgery in patients with more advanced disease. It is of interest whether the sentinel lymph node accurately represents the axillary status after PC and, thus, whether the sentinel node concept can be applied to both groups. METHODS Thirty‐three patients underwent SNB after chemotherapy and prior to axillary lymph node dissection. RESULTS The average greatest tumor dimension before chemotherapy (33 mm ± 2 mm) was significantly larger ( P = 0.000) than after therapy (20 mm ± 3 mm). Histopathologic complete remission was seen in only three patients. One or two sentinel lymph nodes (average, 1.7 lymph nodes) were identified with certainty in 29 of 33 procedures and accurately predicted axillary lymph node status in all of these patients. Breast‐conserving surgery was possible in 21 patients (64%), and axillary lymph nodes were involved in 22 patients (67%). CONCLUSIONS Even after patients undergo PC, SNB seems to be a reliable method for accurate staging of the axilla in those more advanced breast carcinoma. Thus, axillary dissection may be avoided in certain patients. Lymph node involvement seems to be likely in women with suspicious axillary findings before chemotherapy who have no visible sentinel lymph nodes on preoperative lymphosintigraphy and in patients without recurrent tumors. Further investigation of the SNB concept in this patient group should be evaluated in larger studies. Cancer 2001;92:1080–4. © 2001 American Cancer Society.