This clinical trial is designed as prospective, observational, non-randomized clinical trial of overall duration of 8-9 years, 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 tumor dimensions, pathological report of core needle biopsy, ultrasound evaluation of axillary lymph nodes and cytologicaly proven positive lymph nodes, patients would be divided in three predefined groups and would undergo through 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 afterward by adjuvant oncological treatment. Before neoadjuvant treatment all patients would undergo magnetic resonance (MR) imaging and ultrasound guided placement titanium clip in primary tumor site. Clinical assessment of effectiveness of neoadjuvant treatment would be evaluate by breast MR imaging in the middle and at the end of the neoadjuvant systemic treatment.~Group 3 (T1-3 N1-2 M0) protocol include the Group 2 protocol in addition with FNA (cytology) prove 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 presence of any size residual tumor in lymph node(s) in group 2 and 3 axillary lymph node dissection would be made.~All patients would be controlled periodically in postoperative five years follow up period to determine the prevalence of locoregional recurrence, progression of disease to M1 stage and overall survival rate.~The results would be compared among groups, to available literature data and to our former data of patients of same stage but treated in period from 2011 till 2014 (i.e. without neoadjuvant therapy).~In addition, all marked nodes (group 3) would be examined for presence or absence of intraoperative signal and presence or absence of any residual tumor.~In the first phase, that 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 last 30 patients in each group.~All patients participating in this trial and all members of investigation team would be completely introduced to plan and aims of this trial.~Two main hypothesis of this trial are that SLNB does not have 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 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 reliable approach for sugical axillary management and that does not have negative impact on the oncological principles and clinical outcome.~Data would be collected individually for each patient during diagnostic and therapeutic period and in follow up period (periodic ambulance controls) for 5 postoperative years.~Data would be recorded on appropriated forms. After data completion, leading investigator would import encoded data in register. All data would be available to all members of 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.
This clinical trial is designed as observational study of overall duration of 8-9 years, but the first results and conclusions could be achieved in 3-4 years. In the first phase, that would last 3-4 years, the investigators will form three predetermined groups of breast cancer patients that would be monitored in the second phase for 5 postoperative years.~All patients involved in this trial would undergo defined protocol. All patients participating in this trial and all members of investigation team would be completely introduced to plan and aims of this trial.~Two main hypothesis of this trial are that SLNB does not have 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 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 reliable approach for sugical axillary management.~Data would be collected individually for each patient and recorded on appropriated forms. After data completion, leading investigator would import encoded data in register. Data collected in this trial would be used for publications.