Locally advanced breast cancer: Tumor-infiltrating lymphocytes as a predictive factor of response to neoadjuvant chemotherapy.

OBJECTIVE: To evaluate the pathologic response after neoadjuvant chemotherapy in patients with breast cancer according to the stromal tumor-infiltrating lymphocytes (TILs) as well as the evaluation of overall and disease-free survival according to TILs. METHODS: A six years (2008-2013) review was done including patients with locally advanced breast cancer that received neoadjuvant therapy and then surgery. An evaluation of the percentage of TILs was done in the pretreatment biopsies and a correlation analysis and survival curves were done. RESULTS: 187 patients were evaluated. The pathological complete response (pCR) in patients with TILs ≥30% was 58.5%, and in patients with TILs < 30% was 11% (p <0.001). An Odds Ratio of 8.85 was obtained in patients with TILs ≥30% to achieve a pCR. This relationship was seen in patients with HER2-enriched and triple-negative subtypes. No correlation between TILs and survival was obtained (OS: log-rank; p = 0.834; DFS: log-rank; p = 0.937). CONCLUSIONS: The study of TILs is important because they represent an additional tool to predict the response to neoadjuvant treatment mostly in HER2-enriched and triple-negative subtypes of breast cancer.

Frozen section evaluation of sentinel lymph nodes in breast carcinoma: a retrospective analysis.

OBJECTIVE: To determine the false-negative rate, sensitivity, and diagnostic accuracy of the frozen section analysis of the sentinel lymph node (SLN) biopsy in early-stage breast cancer compared to the definitive section and to identify the factors that could be associated with the appearance of false-negative cases. Secondarily, to evaluate the pathological results of cases submitted to completion axillary lymph node dissection (ALND) for positive SLN. METHODS: We performed a five-year review of cases (2011-2015), including patients with early-stage breast cancer undergoing SLN biopsy, with frozen section evaluation and subsequent definitive pathological analysis. These results were compared to calculate the false-negative rate and the factors associated with it. The histopathological findings were also evaluated in patients submitted to completion ALND. RESULTS: A total of 281 patients were evaluated, identifying 18 cases with frozen section results as false negative (false-negative rate: 23.7%), and 55.5% of these cases were micrometastases. The false-negative rate in SLN with macrometastasis was 13.1% and for micrometastasis cases was 66.7% (p < 0.001). True-positive patients that were submitted to completion ALND had additional axillary lymph nodes with metastases in 28% of cases, whereas the group of false negatives had additional positive axillary lymph nodes in 40% of patients (p = 0.62). CONCLUSION: Frozen section analysis had a false-negative rate acceptable in SLN biopsy in our institution, and the micrometastasis in the SLN was the most important factor associated with the appearance of this phenomenon.