***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: Background The aim was to prove the low identification rate of sentinel lymph node biopsy ( SNB ) and to determine the feasibility of replacing axillary lymph node dissection ( AND ) in axillary lymph node positive patients after chemotherapy .  Methods From October 2001 to July 2005 , 875 consecutive patients with primary operable breast cancer underwent SNB and AND .  Among them , 238 received pre-operative chemotherapy .  We compared the identification rate , false negative rate ( FNR ) , negative predictive value ( NPV ) , and accuracy of  SNB  in clinical ly node-positive patients with or without chemotherapy .  Results The identification rate was significantly lower in patients received chemotherapy ( 77.6 % ) than in those not received it ( 97.0 % ) ( P < 0.001 ) . In those received the therapy , the FNR was 5.6 % , the NPV was 86.8 % , and the accuracy was 95.9 % . In those not received therapy , the FNR was 7.4 % and the accuracy was 92.6 % ( differences not statistically significant ) . Conclusion The identification rate in confirmed axillary lymph node-positive patients was significantly lower in patients received pre-operative chemotherapy , but accuracy did not differ significantly between the two groups . Thus , for patients who achieve complete axillary clearance by chemotherapy , SNB could replace AND PURPOSE Multicentric breast cancer has been considered to be a contraindication for sentinel node ( SN ) biopsy ( SNB ) . In this prospect i ve multi-institutional trial , SNB-feasibility and accuracy was evaluated in 142 patients with multicentric cancer from the Austrian Sentinel Node Study Group ( ASNSG ) and compared with data from 3,216 patients with unicentric cancer . PATIENTS AND METHODS Between 1996 and 2004 , 3,730 patients underwent SNB at 15 ASNSG-affiliated hospitals . Patient data were entered in a multicenter data base . One hundred forty-two patients presented with multicentric invasive breast cancer and underwent SNB .  RESULTS Intraoperatively , a mean number of 1.67 SNs were excised ( identification -rate , 91.5 % ) . The incidence of SN metastases was 60.8 % ( 79 of 130 ) . This was confirmed by axillary lymph node dissection ( ALND ) in 125 patients . Of patients with positive SNs , 60.8 % ( 48 of 79 ) showed involvement of nonsentinel nodes ( NSNs ) , as did three patients with negative SNs ( false-negative rate , 4.0 ) . Sensitivity , negative predictive value , and overall accuracy were 96.0 % , 93.3 % , and 97.3 % , respectively . Ninety-one percent of the patients underwent mastectomy , and 9 % were treated with breast conserving surgery . None of the patients have shown axillary recurrence so far ( mean follow-up , 28.8 months ) . Compared with 3,216 patients with unicentric cancer , there was a significantly higher rate of SN metastases as well as in NSNs , whereas there was no difference in detection and false-negative rates . CONCLUSION Multicentric breast cancer is a new indication for SNB without routine ALND in controlled trials . Given adequate quality control and an interdisciplinary teamwork of surgical , nuclear medicine , and pathology units , SNB is both feasible and accurate in this disease entity PURPOSE Sentinel lymph node ( SLN ) biopsy has proved to be an accurate method for detecting nodal micrometastases in previously untreated patients with early-stage breast cancer . We investigated the accuracy of this technique for patients with more advanced breast cancer after neoadjuvant chemotherapy .  PATIENTS AND METHODS Patients with stage II or III breast cancer who had undergone doxorubicin-based neoadjuvant chemotherapy before breast surgery were eligible . Intraoperative lymphatic mapping was performed with peritumoral injections of blue dye alone or in combination with technetium-labeled sulfur colloid . All patients were offered axillary lymph node dissection . Negative sentinel and axillary nodes were subjected to additional processing with serial step sectioning and immunohistochemical staining with an anticytokeratin antibody to detect micrometastases . RESULTS Fifty-one patients underwent SLN biopsy after neoadjuvant chemotherapy from 1994 to 1999 . The SLN identification rate improved from 64.7 % to 94.1 % . Twenty-two ( 51.2 % ) of the 43 successfully mapped patients had positive SLNs , and in 10 of those 22 patients ( 45.5 % ) , the SLN was the only positive node . Three patients had false-negative SLN biopsy ; that is , the sentinel node was negative , but at least one nonsentinel node contained metastases . Additional processing revealed occult micrometastases in four patients ( three in sentinel nodes and one in a nonsentinel node ) . CONCLUSION SLN biopsy is accurate after neoadjuvant chemotherapy . The SLN identification improved with experience . False-negative findings occurred at a low rate throughout the series . This technique is a potential way to guide the axillary treatment of patients who are clinical ly node negative after neoadjuvant chemotherapy 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 BACKGROUND Sentinel lymph node biopsy in women with operable breast cancer is routinely used in some countries for staging the axilla despite limited data from r and omized trials on morbidity and mortality outcomes . We conducted a multicenter r and omized trial to compare quality -of-life outcomes between patients with clinical ly node-negative invasive breast cancer who received sentinel lymph node biopsy and patients who received st and ard axillary treatment .  METHODS The primary outcome measures were arm and shoulder morbidity and quality of life .  From November 1999 to October 2003 , 1031 patients were r and omly assigned to undergo sentinel lymph node biopsy ( n = 515 ) or st and ard axillary surgery ( n = 516 ) . Patients with sentinel lymph node metastases proceeded to delayed axillary clearance or received axillary radiotherapy ( depending on the protocol at the treating institution ) . Intention-to-treat analyses of data at 1 , 3 , 6 , and 12 months after surgery are presented . All statistical tests were two-sided . RESULTS The relative risks of any lymphedema and sensory loss for the sentinel lymph node biopsy group compared with the st and ard axillary treatment group at 12 months were 0.37 ( 95 % confidence interval [ CI ] = 0.23 to 0.60 ; absolute rates : 5 % versus 13 % ) and 0.37 ( 95 % CI = 0.27 to 0.50 ; absolute rates : 11 % versus 31 % ) , respectively . Drain usage , length of hospital stay , and time to resumption of normal day-to-day activities after surgery were statistically significantly lower in the sentinel lymph node biopsy group ( all P < .001 ) , and axillary operative time was reduced ( P = .055 ) . Overall patient-recorded quality of life and arm functioning scores were statistically significantly better in the sentinel lymph node biopsy group throughout ( all P < or = .003 ) . These benefits were seen with no increase in anxiety levels in the sentinel lymph node biopsy group ( P > .05 ) . CONCLUSION Sentinel lymph node biopsy is associated with reduced arm morbidity and better quality of life than st and ard axillary treatment and should be the treatment of choice for patients who have early-stage breast cancer with clinical ly negative nodes BACKGROUND The optimum timing of sentinel-lymph-node biopsy for breast cancer patients treated with neoadjuvant chemotherapy  is uncertain . The SENTINA ( SENTinel NeoAdjuvant ) study was design ed to evaluate a specific algorithm for timing of a st and ardised sentinel-lymph-node biopsy procedure in patients who undergo neoadjuvant chemotherapy .  METHODS SENTINA is a four-arm , prospect i ve , multicentre cohort study undertaken at 103 institutions in Germany and Austria . Women with breast cancer who were scheduled for neoadjuvant chemotherapy were enrolled into the study . Patients with clinical ly node-negative disease ( cN0 ) underwent sentinel-lymph-node biopsy before neoadjuvant chemotherapy ( arm A ) . If the sentinel node was positive ( pN1 ) , a second sentinel-lymph-node biopsy procedure was done after neoadjuvant chemotherapy ( arm B ) . Women with clinical ly node-positive disease ( cN+ ) received neoadjuvant chemotherapy . Those who converted to clinical ly node-negative disease after chemotherapy ( ycN0 ; arm C ) were treated with sentinel-lymph-node biopsy and axillary dissection . Only patients whose clinical nodal status remained positive ( ycN1 ) underwent axillary dissection without sentinel-lymph-node biopsy ( arm D ) . The primary endpoint was accuracy ( false-negative rate ) of sentinel-lymph-node biopsy after neoadjuvant chemotherapy  for patients who converted from cN1 to ycN0 disease during neoadjuvant chemotherapy ( arm C ) . Secondary endpoints included comparison of the detection rate of sentinel-lymph-node biopsy before and after neoadjuvant chemotherapy  , and also the false-negative rate and detection rate of sentinel-lymph-node biopsy after removal of the sentinel lymph node . Analyses were done according to treatment received ( per protocol ) . FINDINGS Of 1737 patients who received treatment , 1022 women underwent sentinel-lymph-node biopsy before neoadjuvant chemotherapy ( arms A and B ) , with a detection rate of 99.1 % ( 95 % CI 98.3 - 99.6 ; 1013 of 1022 ) . In patients who converted after neoadjuvant chemotherapy from cN+ to ycN0 ( arm C ) , the detection rate was 80.1 % ( 95 % CI 76.6 - 83.2 ; 474 of 592 ) and false-negative rate was 14.2 % ( 95 % CI 9.9 - 19.4 ; 32 of 226 ) . The false-negative rate was 24.3 % ( 17 of 70 ) for women who had one node removed and 18.5 % ( 10 of 54 ) for those who had two sentinel nodes removed ( arm C ) . In patients who had a second sentinel-lymph-node biopsy procedure after neoadjuvant chemotherapy ( arm B ) , the detection rate was 60.8 % ( 95 % CI 55.6 - 65.9 ; 219 of 360 ) and the false-negative rate was 51.6 % ( 95 % CI 38.7 - 64.2 ; 33 of 64 ) . INTERPRETATION Sentinel-lymph-node biopsy is a reliable diagnostic method before neoadjuvant chemotherapy . After systemic treatment or early sentinel-lymph-node biopsy , the procedure has a lower detection rate and a higher false-negative rate compared with sentinel-lymph-node biopsy done before neoadjuvant chemotherapy . These limitations should be considered if biopsy is planned after neoadjuvant chemotherapy . FUNDING Brustkrebs Deutschl and , 
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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 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