***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: OBJECTIVE To evaluate factors affecting sentinel lymph node ( SLN ) identification after neoadjuvant chemotherapy ( NAC ) in patients with initial node-positive breast cancer . BACKGROUND SLN surgery is increasingly used for nodal staging after NAC and optimal technique for SLN identification is important . METHODS The American College of Surgeons Oncology Group Z1071 prospect i ve trial enrolled clinical T0 - 4 , N1 - 2 , M0 breast cancer patients . After NAC , SLN surgery and axillary lymph node dissection ( ALND ) were planned . Multivariate logistic regression modeling assessing factors influencing SLN identification was performed . RESULTS Of 756 patients enrolled , 34 women withdrew , 21 were ineligible , 12 underwent ALND only , and 689 had SLN surgery attempted . At least 1 SLN was identified in 639 patients ( 92.7 % : 95 % CI : 90.5%-94.6 % ) . Among factors evaluated , mapping technique was the only factor found to impact SLN identification ; with use of blue dye alone increasing the likelihood of failure to identify the SLN relative to using radiolabeled colloid + /- blue dye ( P = 0.006 ; OR = 3.82 ; 95 % CI : 1.47 - 9.92 ) . The SLN identification rate was 78.6 % with blue dye alone ; 91.4 % with radiolabeled colloid and 93.8 % with dual mapping agents . Patient factors ( age , body mass index ) , tumor factors ( clinical T or N stage ) , pathologic nodal response to chemotherapy , site of tracer injection , and length of chemotherapy treatment did not significantly affect the SLN identification rate . CONCLUSIONS The SLN identification rate after NAC was higher when mapping was performed using radiolabeled colloid alone or with blue dye compared with blue dye alone . Optimal tracer use is important to ensure successful identification of SLN(s ) after NAC PURPOSE To determine the detection rate , the false-negative rate , and the accuracy of sentinel lymph node ( SLN ) detection after neoadjuvant chemotherapy ( NAC ) for advanced breast cancer . PATIENTS AND METHODS A prospect i ve multicentric study was initiated to evaluate the results of  SLN biopsy with the combined method after NAC for advanced large operable breast cancer . RESULTS From September 2003 to March 2007 , 195 patients enrolled from 12 institutions were found suitable for evaluation . The detection rate was 90 % ( 176 of 195 patients ) , and the false-negative rate was 11.5 % ( six of 52 patients ) . Patients without axillary palpable nodes ( N0 ) before NAC had a better detection rate compared with patients with axillary suspicious nodes ( N1 , 94.6 % v 81.5 % ; P = .008 ) . The false-negative rate was not correlated with clinical nodal status before NAC ( 9.4 % v 15 % ; P = .66 ) . CONCLUSION This study confirms the feasibility of SLN biopsy after NAC in the case of large operable breast cancer . The detection rate , false-negative rate , and accuracy do not differ from those obtained in the case of early breast cancer without NAC , thus demonstrating the feasibility of SLN biopsy after NAC INTRODUCTION A controversial aspect of breast cancer management is the use of sentinel lymph node biopsy ( SLNB ) in patients requiring neoadjuvant chemotherapy ( NCT ) .  This paper discusses the detection rate ( DT ) and false negatives ( FN ) of SLNB after NCT to investigate the influence of initial nodal disease and the protocol s applied . METHODS Prospect i ve observational multicenter study in women with breast cancer , treated with NCT and SLNB post-NCT with subsequent lymphadenectomy .  DT and FN rates were calculated , both overall and depending on the initial nodal status or the use of diagnostic protocol s pre-SLNB . RESULTS No differences in DT between initial node-negative cases and positive cases were found ( 89.8 vs. 84.4 % , P=.437 ) . Significant differences were found ( 94.1 vs. 56.5 % , P=0,002 ) in the negative predictive value , which was lower when there was initial lymph node positivity , and a higher rate of FN , not significant ( 18.2 vs. 43.5 % , P=.252 ) in the same cases . The axillary study before SLNB and after the NCT , significantly decreased the rate of FN in patients with initial involvement ( 55.6 vs 12.5 , P=0,009 ) . CONCLUSIONS NCT means less DT and a higher rate of FN in subsequent SLNB , especially if there is initial nodal involvement . The use of protocol s in axillary evaluation after administering the NCT and before BSGC , decreases the FN rate in these patients Purpose To provide current recommendations on the use of sentinel node biopsy ( SNB ) for patients with early-stage breast cancer . Methods PubMed and the Cochrane Library were search ed for r and omized controlled trials , systematic review s , meta-analyses , and clinical practice guidelines from 2012 through July 2016 . An Up date Panel review ed the identified abstract s. Results Of the eight publications identified and review ed , none prompted a change in the 2014 recommendations , which are reaffirmed by the up date d literature review . Conclusion Women without sentinel lymph node ( SLN ) metastases should not receive axillary lymph node dissection ( ALND ) . Women with one to two metastatic SLNs who are planning to undergo breast-conserving surgery with whole-breast radiotherapy should not undergo ALND ( in most cases ) . Women with SLN metastases who will undergo mastectomy should be offered ALND . These three recommendations are based on r and omized controlled trials . Women with operable breast cancer and multicentric tumors , with ductal carcinoma in situ , who will undergo mastectomy , who previously underwent breast and /or axillary surgery , or who received preoperative/neoadjuvant systemic therapy may be offered SNB .  Women who have large or locally advanced invasive breast cancer ( tumor size T3/T4 ) , inflammatory breast cancer , or ductal carcinoma in situ ( when breast-conserving surgery is planned ) or are pregnant should not undergo SNB PURPOSE To develop a guideline for the use of sentinel node biopsy ( SNB ) in early stage breast cancer . METHODS An American Society of Clinical Oncology ( ASCO ) Expert Panel conducted a systematic review of the literature available through February 2004 on the use of SNB in early-stage breast cancer . The panel developed a guideline for clinicians and patients regarding the appropriate use of a sentinel lymph node identification and sampling procedure from hereon referred to as SNB . The guideline was review ed by selected experts in the field and the ASCO Health Services Committee and was approved by the ASCO Board of Directors . RESULTS The literature review identified one published prospect i ve r and omized controlled trial in which SNB was compared with axillary lymph node dissection ( ALND ) , four limited meta-analyses , and 69 published single-institution and multicenter trials in which the test performance of SNB was evaluated with respect to the results of ALND ( completion axillary dissection ) . There are currently no data on the effect of SLN biopsy on long-term survival of patients with breast cancer . However , a review of the available evidence demonstrates that , when performed by experienced clinicians , SNB appears to be a safe and acceptably accurate method for identifying early-stage breast cancer without involvement of the axillary lymph nodes . CONCLUSION SNB is an appropriate initial alternative to routine staging ALND for patients with early-stage breast cancer with clinical ly negative axillary nodes . Completion ALND remains st and ard treatment for patients with axillary metastases identified on SNB . Appropriately identified patients with negative results of SNB , when done under the direction of an experienced surgeon , need not have completion ALND . Isolated cancer cells detected by pathologic examination of the SLN with use of specialized techniques are currently of unknown clinical significance . Although such specialized techniques are often used , they are not a required part of SLN evaluation for breast cancer at this time . Data suggest that SNB is associated with less morbidity than ALND , but the comparative effects of these two approaches on tumor recurrence or patient survival are unknown The timing of the sentinel lymph node biopsy ( SNB ) is controversial in clinical ly node negative patients receiving neoadjuvant chemotherapy ( NAC ) .  We studied variation in the timing of axillary staging in breast cancer patients who received NAC and the subsequent axillary treatment in The Netherl and s. Patients diagnosed with clinical ly node negative primary breast cancer between 1st January 2010 and 30th June 2013 who received NAC and SNB were selected from the Netherl and s Cancer Registry . Data on patient and tumour characteristics , axillary staging and treatment were analysed . Two groups were defined : ( 1 ) patients with SNB before NAC ( N=980 ) and ( 2 ) patients with SNB after NAC ( N=203 ) . Eighty-three percent of patients underwent SNB before NAC , with large regional variation ( 35 - 99 % ) . The SN identification rate differed for SNBs conducted before and after NAC ( 98 % versus 95 % ; p=0.032 ) . A lower proportion of patients had a negative SNB when assessed before NAC compared to after ( 54 % versus 67 % ; p=0.001 ) . The proportion of patients receiving any axillary treatment was higher for those with SNB before NAC than after ( 45 % versus 33 % ; p=0.006 ) . In conclusion , variation exists in the timing of SNB in clinical practice in The Netherl and s for clinical ly node negative breast cancer patients receiving NAC . The post-NAC SN procedure is , despite some lower SN identification rate , associated with a significantly less frequent axillary treatment and thus with less expected morbidity . The effect on recurrence rate is not yet clear . Patients in this registry will be followed prospect ively for long-term outcome AIM To evaluate the accuracy of sentinel lymph node biopsy ( SLNB ) in operable breast cancer patients treated with neoadjuvant chemotherapy ( NAC ) .  MATERIAL S AND METHODS Between January 2008 - 2011 , 88 women , mean age 49.4 years , with infiltrating breast carcinoma , were studied prospect ively . Patients were T1 - 3 , N0 - 1 , M0 . Prior to surgery , the patients received chemotherapy ( epirubicin/cyclophosphamide , docetaxel ) , and trastuzumab in Her2/neu-positive patients . Axillary status was established by physical examination , ultrasound-guided core needle biopsy of any suspicious lymph node . The day before surgery , 74 - 111 MBq of (99m)Tc-albumin nanocolloid was injected periareolarly . All patients underwent breast surgery , with SLNB , followed by complete axillary lymph node dissection ( ALND ) . Sentinel lymph node ( SLN ) were examined by frozen sections , hematoxylin-eosin staining and immunohistochemical analysis or One Step Nucleic Acid Amplification ( OSNA ) . RESULTS Mean tumor size : 3.5 cm . Histologic type : 69 invasive ductal , 16 invasive lobular and 3 others . Thirty seven patients had clinical /ultrasound node-positive at presentation . Clinical response of primary tumor to NAC : complete in 38 , partial in 45 , and stable disease in 5 patients . A pathological complete response was achieved in 25 . All patients were clinical ly node-negative after NAC . SLN identification rate was 92.0 % . Six of 7 patients in whom SLN was not found had clinical /ultrasound positive axilla before NAC . SLN accurately determined the axillary status in 96.5 % . False negative rate was 8.3 % . In 69.4 % of patients , SLN was the only positive node . The mean number of SLN removed was 1.7 and nodes resected from the ALND were 13.2 . CONCLUSION SLN biopsy after NAC can predict the axillary status with a high accuracy in patients with breast cancer , avoiding unnecessary ALND BACKGROUND Examination was performed on pathologic material from patients enrolled in the National Surgical Adjuvant Breast Project ( NSABP ) protocol B-18 , in which the clinical effects of preoperative ( preop ) and postoperative ( postop ) doxorubicin and cyclophosphamide ( AC ) were compared . METHODS Of the total number of 1523 patients , 1234 patients ( 81 % ) were in the pathologically evaluable cohort . Six hundred twenty-six patients had been r and omized prospect ively to receive AC postop and 608 had been r and omized to receive AC preop .  Preentry diagnosis was made by fine-needle aspiration ( FNA ) and /or Tru-cut biopsy ( TC ) . AC-induced and other pathologic changes were identified , and their relation to pathologic response and overall survival ( OS ) and disease-free survival ( DFS ) was determined . Frequencies of the number of lymph node metastases , their size , stromal reaction , and extracapsular extension ( ECE ) were compared in the two treatment groups , as was their correlation with OS and DFS . Survival estimates were based on 9 years of follow-up . RESULTS Approximately 13 % of primary breast carcinoma cases exhibited both a clinical complete response ( cCR ) and a pathologic complete response ( absence of invasive tumor [ 
    Output:
    
Conclusion Based on current evidence , SLNB is technically feasible and accurate enough for axillary staging in initially clinical ly node-negative breast cancer patients after NAC