Sentinel lymph node biopsy following neoadjuvant chemotherapy: an evidence-based review and recommendations for current practice.

Sentinel lymph node biopsy (SLNB) at upfront surgery is the gold-standard surgical method for axillary lymph node staging in early stage breast cancer: the technique provides adequate information regarding axillary status, with similar oncological safety and lower morbidity compared to axillary dissection, despite the false negative rates. Neoadjuvant chemotherapy (NACT), traditionally used for locally advanced breast cancer, plays an important role in the treatment of early stage breast cancer, making downstaging possible in axillary lymph node and breast cancer, thus minimizing the impact of surgery and reducing morbidity, as well as enabling patients with residual disease to be selected for adjuvant treatment. In this respect, the role of SLNB has proved controversial, particularly in view of the lack of data from randomized clinical trials on this subject. Currently, the de-escalation of axillary surgery after NACT is mainly based on retrospectives studies and false negative rates. This paper reviews current evidence on the management of axillary surgery following NACT under different circumstances, with suggested recommendations in each scenario: clinically negative nodes at diagnosis and SLNB after NACT, clinically positive nodes at diagnosis and SLNB after NACT, positive SLNB following NACT and finally the possibility of omitting axillary surgery in good responders.

Real-world assessment of the effect of impact of tumor size on pathological complete response rates in triple negative breast cancer after neoadjuvant chemotherapy.

BACKGROUND: Triple negative breast cancer (TNBC) is characterized rapid tumor growth, and increased metastatic potential compared to other breast cancer subtypes. However, pathological complete response (pCR) to neoadjuvant chemotherapy (NACT) can predict patients with a better prognosis. Clinical predictors of pCR such as tumor size (TS) are controversial. This study aims to evaluate the influence of TS on achieving pCR, and the associated survival outcomes. METHODS: Medical records from 310 TNBC patients treated with NACT between 2010 and 2013 in National Cancer Institute Brazil were screened. The aim study was to examine the impact of TS on pCR. We used descriptive statistics to organize and summarize TS data and all the other variables of interest. Logistic regression has done to assess if any of these variables were associated with pCR. Survival data were extrapolated using Kaplan-Meier analysis and log-rank tests. RESULTS: Thirty-nine (21%) of 187 enrolled patients achieved pCR. Median age was 48 years, 50.27% were postmenopausal, 93.03% T3/T4 and 75.39% axillar clinical node-positive; 92.51% received an anthracycline regimen followed by a taxane. Age >40 years (P=0.04, OR 0.45, 95% CI, 0.20-0.95) and tumor infiltrating lymphocytes (TILs) presence (P<0.01, OR 3.71, 95% CI, 1.60-8.60) were factors significantly associated with increased rates of pCR. Neither the TS (IQR: 4; P=0.22, OR 0.93, 95% CI, 0.83-1.03) nor the other subgroups analysed demonstrated any association with achieving pCR. Median follow-up was 36 months. The 5-year OS and RFS of the study population was 71.20% and 61.10% respectively. CONCLUSIONS: Preoperative TS did not significantly impact pCR rate in our cohort of patients receiving NACT for TNBC. Characteristics associated with higher pCR rate included TILs and age >40 years. In addition, pCR, was indicative of better survival outcomes.