***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: PURPOSE A subset of head and neck cancers is associated with the human papillomavirus ( HPV ) . Viral infection is closely correlated with expression of p16(INK4A ) in these tumors . We evaluated  p16(INK4A )  as a prognostic marker of treatment response and survival in a well-defined and prospect ively collected cohort of patients treated solely with conventional radiotherapy in the Danish Head and Neck Cancer Group ( DAHANCA ) 5 trial . PATIENTS AND METHODS Immunohistochemical expression of p16(INK4A ) was analyzed in pretreatment paraffin-embedded tumor blocks from 156 patients treated with conventional primary radiotherapy alone .  The influence of p16(INK4A ) status on locoregional tumor control , disease-specific survival , and overall survival after radiotherapy  was evaluated . RESULTS p16(INK4A ) positivity was found in 35 tumors ( 22 % ) . Tumor-positivity for p16(INK4A ) was significantly correlated with improved locoregional tumor control ( 5-year actuarial values 58 % v 28 % ; P = .0005 ) , improved disease-specific survival ( 72 % v 34 % ; P = .0006 ) , and improved overall survival ( 62 % v 26 % ; P = .0003 ) . In multivariate analysis , p16(INK4A ) remained a strong independent prognostic factor for locoregional failure ( hazard ratio [ HR ] , 0.35 ; 95 % CI , 0.19 to 0.64 ) , disease-specific death ( HR , 0.36 ; 95 % CI , 0.20 to 0.64 ) , and overall death ( HR , 0.44 ; 95 % CI , 0.28 to 0.68 ) . CONCLUSION Expression of p16(INK4A ) has a major impact on treatment response and survival in patients with head and neck cancer treated with conventional radiotherapy PURPOSE To investigate the safety and clinical utility of the sentinel node procedure in early-stage vulvar cancer patients . PATIENTS AND METHODS A multicenter observational study on sentinel node detection using radioactive tracer and blue dye was performed in patients with T1/2 ( < 4 cm ) squamous cell cancer of the vulva . When the sentinel node was found to be negative at pathologic ultrastaging , inguinofemoral lymphadenectomy was omitted , and the patient was observed with follow-up for 2 years at intervals of every 2 months . Stopping rules were defined for the occurrence of groin recurrences . RESULTS From March 2000 until June 2006 , a sentinel node procedure was performed in 623 groins of 403 assessable patients . In 259 patients with unifocal vulvar disease and a negative sentinel node ( median follow-up time , 35 months ) , six groin recurrences were diagnosed ( 2.3 % ; 95 % CI , 0.6 % to 5 % ) , and 3-year survival rate was 97 % ( 95 % CI , 91 % to 99 % ) . Short-term morbidity was decreased in patients after sentinel node dissection only when compared with patients with a positive sentinel node who underwent inguinofemoral lymphadenectomy ( wound breakdown in groin : 11.7 % v 34.0 % , respectively ; P < .0001 ; and cellulitis : 4.5 % v 21.3 % , respectively ; P < .0001 ) . Long-term morbidity also was less frequently observed after removal of only the sentinel node compared with sentinel node removal and inguinofemoral lymphadenectomy ( recurrent erysipelas : 0.4 % v 16.2 % , respectively ; P < .0001 ; and lymphedema of the legs : 1.9 % v 25.2 % , respectively ; P < .0001 ) . CONCLUSION In early-stage vulvar cancer patients with a negative sentinel node , the groin recurrence rate is low , survival is excellent , and treatment-related morbidity is minimal . We suggest that sentinel node dissection , performed by a quality -controlled multidisciplinary team , should be part of the st and ard treatment in selected patients with early-stage vulvar cancer BACKGROUND The improved prognosis for patients with human papillomavirus (HPV)-positive head and neck squamous cell carcinoma ( HNSCC ) relative to HPV-negative HNSCC observed in retrospective analyses remains to be confirmed in a prospect i ve clinical trial . METHODS We prospect ively evaluated the association of tumor HPV status with therapeutic response and survival among 96 patients with stage III or IV HNSCC of the oropharynx or larynx who participated in an Eastern Cooperative Oncology Group ( ECOG ) phase II trial and who received two cycles of induction chemotherapy with intravenous paclitaxel and carboplatin followed by concomitant weekly intravenous paclitaxel and st and ard fractionation radiation therapy .  The presence or absence of HPV oncogenic types in tumors was determined by multiplex polymerase chain reaction ( PCR ) and in situ hybridization . Two-year overall and progression-free survival for HPV-positive and HPV-negative patients were estimated by Kaplan-Meier analysis . The relative hazard of mortality and progression for HPV-positive vs HPV-negative patients after adjustment for age , ECOG performance status , stage , and other covariables was estimated by use of a multivariable Cox proportional hazards model . All statistical tests were two-sided . RESULTS Genomic DNA of oncogenic HPV types 16 , 33 , or 35 was located within tumor cell nuclei of 40 % ( 95 % confidence interval [ CI ] = 30 % to 50 % ) of patients with HNSCC of the oropharynx or larynx by in situ hybridization and PCR . Compared with patients with HPV-negative tumors , patients with HPV-positive tumors had higher response rates after induction chemotherapy ( 82 % vs 55 % , difference = 27 % , 95 % CI = 9.3 % to 44.7 % , P = .01 ) and after chemoradiation treatment ( 84 % vs 57 % , difference = 27 % , 95 % CI = 9.7 % to 44.3 % , P = .007 ) . After a median follow-up of 39.1 months , patients with HPV-positive tumors had improved overall survival ( 2-year overall survival = 95 % [ 95 % CI = 87 % to 100 % ] vs 62 % [ 95 % CI = 49 % to 74 % ] , difference = 33 % , 95 % CI = 18.6 % to 47.4 % , P = .005 , log-rank test ) and , after adjustment for age , tumor stage , and ECOG performance status , lower risks of progression ( hazard ratio [ HR ] = 0.27 , 95 % CI = 0.10 to 0.75 ) , and death from any cause ( HR = 0.36 , 95 % CI = 0.15 to 0.85 ) than those with HPV-negative tumors . CONCLUSION For patients with HNSCC of the oropharynx , tumor HPV status is strongly associated with therapeutic response and survival PURPOSE To determine the safety of sentinel lymph node biopsy as a replacement for inguinal femoral lymphadenectomy in selected women with vulvar cancer . PATIENTS AND METHODS Eligible women had squamous cell carcinoma , at least 1-mm invasion , and tumor size ≥ 2 cm and ≤ 6 cm . The primary tumor was limited to the vulva , and there were no groin lymph nodes that were clinical ly suggestive of cancer . All women underwent intraoperative lymphatic mapping , sentinel lymph node biopsy , and inguinal femoral lymphadenectomy . Histologic ultra staging of the sentinel lymph node was prescribed . RESULTS In all , 452 women underwent the planned procedures , and 418 had at least one sentinel lymph node identified . There were 132 node-positive women , including 11 ( 8.3 % ) with false-negative nodes . Twenty-three percent of the true-positive patients were detected by immunohistochemical analysis of the sentinel lymph node . The sensitivity was 91.7 % ( 90 % lower confidence bound , 86.7 % ) and the false-negative predictive value ( 1-negative predictive value ) was 3.7 % ( 90 % upper confidence bound , 6.1 % ) . In women with tumor less than 4 cm , the false-negative predictive value was 2.0 % ( 90 % upper confidence bound , 4.5 % ) . CONCLUSION Sentinel lymph node biopsy is a reasonable alternative to inguinal femoral lymphadenectomy in selected women with squamous cell carcinoma of the vulva 
    Output:
    
Implementation of sentinel lymph node biopsy in patients with tumours not exceeding 4 cm is safe and efficiently eliminates redundant groin dissections .