[Low invasion in sentinel lymph node according to the European Working Group In Breast Screening Pathology (EWGBSP) recommendations and non sentinel invasion risk in breast cancer]. / Atteinte minime du ganglion sentinelle selon les recommandations de l'European Working Group in Breast Screening Pathology (EWGBSP) et risque d'atteinte non sentinelle dans le cancer du sein.

ABSTRACT

OBJECTIVE: Because of variability in histopathological interpretations in studies, it's difficult to elucidate the risk of non-sentinel lymph node involvement in case of sentinel node nanometastases (lesions not larger than 0.2 mm) and micrometastases (lesions not larger than 2 mm but larger than 0.2 mm) in breast cancer. In this study, we have evaluated this risk according to the European Working Group for Breast Screening Pathology (EWGBSP) recommendations. PATIENTS AND METHODS: Among patients who underwent sentinel lymph node dissection between February 2001 and April 2008 in our unit, we reviewed the files of patients who had sentinel lymph node involvement smaller than 2mm. A second interpretation of all sentinel lymph node sections was made according to the EWGBSP recommendations. Each patient had complete axillary dissection. RESULTS: Among 608 patients who had sentinel lymph node dissection for breast cancer, 72 (11.84%) had sentinel lymph node involvement smaller than 2 mm (27 pN0i+ and 45 pN1mi). The percentage of pN1mi patients who had non sentinel involvement is 8.89%. None of pN0i+ patients had non sentinel involvement. DISCUSSION AND CONCLUSION: After making a minimal sentinel lymph node involvement strict interpretation according to EWGBSP restrictive recommendations, nanometastases rate was smaller. Any non sentinel involvement was detected in case of sentinel lymph node nanometastases.