Sentinel Lymph Node Biopsy After Neoadjuvant Treatment in Breast Cancer Patents

This clinical trial is designed as a prospective, observational, non-randomized clinical trial of 8-9 years of overall duration, but the first results and conclusions (secondary outcomes) could be achieved in 3-4 years from the beginning of the study. Based on ultrasound and/or magnetic resonance assessment of primary tumour dimensions, pathological report of core needle biopsy, ultrasound evaluation of axillary lymph nodes and cytologically proven positive lymph nodes, patients would be divided into three predefined groups and would undergo predetermined group protocol. Group 1 (T1-2 N0 M0) protocol: Surgery is primary treatment (quadrantectomy/mastectomy and sentinel lymph node biopsy). Group 2 (T2-3 N0 M0) protocol: Neoadjuvant oncological treatment is primary therapy followed by surgery (quadrantectomy/mastectomy and sentinel lymph node biopsy) and afterwards by adjuvant oncological treatment. Before neoadjuvant treatment, all patients would undergo magnetic resonance (MR) imaging and ultrasound-guided placement titanium clip in the primary tumour site. Clinical assessment of the effectiveness of neoadjuvant treatment would be evaluated by breast MR imaging in the middle and at the end of the neoadjuvant systemic treatment. Group 3 (T1-3 N1-2 M0) protocol includes the Group 2 protocol in addition to FNA (cytology) proof of positive node, ultrasound-guided marking positive node with titanium clip before starting neoadjuvant protocol, ultrasound and MR imaging reevaluation of axillary nodes at the end of neoadjuvant treatment and for those patients who achieve complete clinical remission of axillary lymph nodes, biopsy of marked node would be performed in context of standard surgical procedure (in addition to quadrantectomy/mastectomy and sentinel lymph node biopsy) regardless being sentinel node or not. For the presence of any size residual tumour in lymph node(s) in groups 2 and 3 axillary lymph node dissection will be performed. All patients would be controlled periodically in the postoperative five-year follow-up period to determine the prevalence of locoregional recurrence, progression of disease to the M1 stage and overall survival rate. The results would be compared among groups, to available literature data and our former (historical) data of patients of the same stage but treated in the period from 2011 to 2014 (i.e. without neoadjuvant therapy). In the first phase, which would last 3-4 years, the investigators would form three predetermined groups of breast cancer patients that would be monitored in the second phase for 5 postoperative years and analyse secondary outcome measures. According to statistical analysis made of former data of Clinical Hospital Centar Rijeka, groups should be made of at least 30 patients in each group. All patients participating in this trial and all members of the investigation team would be completely introduced to the plan and aims of this trial. Two main hypotheses of this trial are that SLNB does not have a negative impact on clinical outcomes (locoregional recurrence and overall survival) in initially node-positive patients who achieved complete clinically axillary remission after neoadjuvant systemic treatment and that lymph node status after neoadjuvant treatment is a significantly more relevant prognostic factor than nodal status at the time of diagnosis. Therefore, the aim is to establish that sentinel lymph node biopsy, in node-positive breast cancer patients that achieve clinical remission after neoadjuvant treatment, is a reliable approach for surgical axillary management and that does not have a negative impact on the oncological principles and clinical outcomes. Data would be collected individually for each patient during the diagnostic and therapeutic period and in the follow-up period (periodic ambulance controls) for 5 postoperative years. Data would be recorded on appropriate forms. After data completion, the principal investigator would import encoded data into the register. All data would be available to all members of the investigation team, members of Ethic Committee and a person in charge of statistic analysis. Data collected in this trial would be used for publications and self-control of our multidisciplinary team for breast cancer.