***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 Studies with pertuzumab , a novel anti-HER2 antibody , show improved efficacy when combined with the established HER2-directed antibody trastuzumab in breast cancer therapy . We investigated the combination of pertuzumab or trastuzumab , or both , with docetaxel and the combination of pertuzumab and trastuzumab without chemotherapy in the neoadjuvant setting . METHODS In this multicentre , open-label , phase 2 study , treatment-naive women with HER2-positive breast cancer were r and omly assigned ( 1:1:1:1 ) central ly and stratified by operable , locally advanced , and inflammatory breast cancer , and by hormone receptor expression to receive four neoadjuvant cycles of : trastuzumab ( 8 mg/kg loading dose , followed by 6 mg/kg every 3 weeks ) plus docetaxel ( 75 mg/m(2 ) , escalating , if tolerated , to 100 mg/m(2 ) every 3 weeks ; group A ) or pertuzumab ( loading dose 840 mg , followed by 420 mg every 3 weeks ) and trastuzumab plus docetaxel ( group B ) or pertuzumab and trastuzumab ( group C ) or pertuzumab plus docetaxel ( group D ) . The primary endpoint , examined in the intention-to-treat population , was pathological complete response in the breast . Neither patients nor investigators were masked to treatment . This study is registered with Clinical Trials.gov , number NCT00545688 . FINDINGS Of 417 eligible patients , 107 were r and omly assigned to group A , 107 to group B , 107 to group C , and 96 to group D. Patients given pertuzumab and trastuzumab plus docetaxel ( group B ) had a significantly improved pathological complete response rate ( 49 of 107 patients ; 45·8 % [ 95 % CI 36·1 - 55·7 ] ) compared with those given trastuzumab plus docetaxel ( group A ; 31 of 107 ; 29·0 % [ 20·6 - 38·5 ] ; p=0·0141 ) . 23 of 96 ( 24·0 % [ 15·8 - 33·7 ] ) women given pertuzumab plus docetaxel ( group D ) had a pathological complete response , as did 18 of 107 ( 16·8 % [ 10·3 - 25·3 ] ) given pertuzumab and trastuzumab ( group C ) . The most common adverse events of grade 3 or higher were neutropenia ( 61 of 107 women in group A , 48 of 107 in group B , one of 108 in group C , and 52 of 94 in group D ) , febrile neutropenia ( eight , nine , none , and seven , respectively ) , and leucopenia ( 13 , five , none , and seven , respectively ) . The number of serious adverse events was similar in groups A , B , and D ( 15 - 20 serious adverse events per group in 10 - 17 % of patients ) but lower in group C ( four serious adverse events in 4 % of patients ) . INTERPRETATION Patients given pertuzumab and trastuzumab plus docetaxel ( group B ) had a significantly improved pathological complete response rate compared with those given trastuzumab plus docetaxel , without substantial differences in tolerability .  Pertuzumab and trastuzumab without chemotherapy eradicated tumours in a proportion of women and showed a favourable safety profile . These findings justify further exploration in adjuvant trials and support the neoadjuvant approach for accelerating drug assessment in early breast cancer . FUNDING F Hoffmann-La Roche BACKGROUND We studied the effect on tumour response to neoadjuvant therapy of the substitution of lapatinib for trastuzumab in combination with weekly paclitaxel after doxorubicin plus cyclophosphamide treatment , and of the addition of lapatinib and trastuzumab combined after doxorubicin plus cyclophosphamide treatment in patients with HER2-positive operable breast cancer to determine whether there would be a benefit of dual HER2 blockade in these patients . METHODS For this open-label , r and omised phase 3 trial we recruited women aged 18 years or older with an ECOG performance status of 0 or 1 with operable HER2-positive breast cancer . Each received four cycles of st and ard doxorubicin 60 mg/m(2 ) and cyclophosphamide 600 mg/m(2 ) intravenously on day 1 every 3 weeks followed by four cycles of weekly paclitaxel ( 80 mg/m(2 ) ) intravenously on days 1 , 8 , and 15 , every 4 weeks . Concurrently with weekly paclitaxel , patients received either trastuzumab ( 4 mg/kg load , then 2 mg/kg intravenously ) weekly until surgery , lapatinib ( 1250 mg orally ) daily until surgery , or weekly trastuzumab plus lapatinib ( 750 mg orally ) daily until surgery . After surgery , all patients received trastuzumab to complete 52 weeks of HER2-targeted therapy . R and omisation ( ratio 1:1:1 ) was done central ly with stratification by clinical tumour size , clinical nodal status , hormone-receptor status , and age . The primary endpoint was the pathological complete response in the breast , and analysis was performed on an intention-to-treat population . FINDINGS Patient accrual started on July 16 , 2007 , and was completed on June 30 , 2011 ; 529 women were enrolled in the trial . 519 patients had their pathological response determined .  Breast pathological complete response was noted in 93 ( 52·5 % , 95 % CI 44·9 - 59·5 ) of 177 patients in the trastuzumab group , 91 ( 53·2 % , 45·4 - 60·3 ) of 171 patients in the lapatinib group ( p=0·9852 ) ; and 106 ( 62·0 % , 54·3 - 68·8 ) of 171 patients in the combination group ( p=0·095 ) . The most common grade 3 and 4 toxic effects were neutropenia ( 29 [ 16 % ] patients in the trastuzumab group [ grade 4 in five patients ( 3 % ) , 28 [ 16 % ] in the lapatinib group [ grade 4 in eight patients ( 5 % ) ] , and 29 [ 17 % ] in the combination group [ grade 4 in nine patients ( 5 % ) ] ) and grade 3 diarrhoea ( four [ 2 % ] patients in the trastuzumab group , 35 [ 20 % ] in the lapatinib group , and 46 [ 27 % ] in the combination group ; p<0·0001 ) . Symptomatic congestive heart failure defined as New York Heart Association Class III or IV events occurred in seven ( 4 % ) patients in the trastuzumab group , seven ( 4 % ) in the lapatinib group , and one ( < 1 % ) in the combination group ; p=0·185 ) . INTERPRETATION Substitution of lapatinib for trastuzumab in combination with chemotherapy result ed in similar high percentages of pathological complete response . Combined HER2-targeted therapy produced a numerically but insignificantly higher pathological complete response percentage than single-agent HER2-directed therapy ; these findings are consistent with results from other studies . Trials are being undertaken to further assess these findings in the adjuvant setting Overexpression of human epidermal growth factor receptor-2 ( HER2 ) in metastatic breast cancer ( MBC ) is associated with poor prognosis . This single-arm open-label trial ( EGF109491 ; NCT00508274 ) was design ed to confirm the efficacy and safety of lapatinib in combination with capecitabine in 52 heavily pretreated Chinese patients with HER2-positive MBC . The primary endpoint was clinical benefit rate ( CBR ) . Secondary endpoints included progression-free survival ( PFS ) , time to response ( TTR ) , duration of response ( DoR ) , central nervous system ( CNS ) as first site of relapse , and safety . The results showed that there were 23 patients with partial responses and 7 patients with stable disease , result ing in a CBR of 57.7 % . The median PFS was 6.34 months ( 95 % confidence interval , 4.93–9.82 months ) . The median TTR and DoR were 4.07 months ( range , 0.03–14.78 months ) and 6.93 months ( range , 1.45–9.72 months ) , respectively . Thirteen ( 25.0 % ) patients had new lesions as disease progression . Among them , 2 ( 3.8 % ) patients had CNS disease reported as the first relapse . The most common toxicities were palmar-plantar erythrodysesthesia ( 59.6 % ) , diarrhea ( 48.1 % ) , rash ( 48.1 % ) , hyperbilirubinemia ( 34.6 % ) , and fatigue ( 30.8 % ) . Exploratory analyses of oncogenic mutations of PIK3CA suggested that of 38 patients providing a tumor sample , baseline PIK3CA mutation status was not associated with CBR ( P = 0.639 ) or PFS ( P = 0.989 ) . These data confirm that the lapatinib plus capecitabine combination is an effective and well-tolerated treatment option for Chinese women with heavily pretreated MBC , irrespective of PIK3CA status BACKGROUND The anti-HER2 monoclonal antibody trastuzumab and the tyrosine kinase inhibitor lapatinib have complementary mechanisms of action and synergistic antitumour activity in models of HER2-overexpressing breast cancer . We argue that the two anti-HER2 agents given together would be better than single-agent therapy . METHODS In this parallel groups , r and omised , open-label , phase 3 study undertaken between Jan 5 , 2008 , and May 27 , 2010 , women from 23 countries with HER2-positive primary breast cancer with tumours greater than 2 cm in diameter were r and omly assigned to oral lapatinib ( 1500 mg ) , intravenous trastuzumab ( loading dose 4 mg/kg [ DOSAGE ERROR CORRECTED ] , subsequent doses 2 mg/kg ) , or lapatinib ( 1000 mg ) plus trastuzumab . Treatment allocation was by stratified , permuted blocks r and omisation , with four stratification factors . Anti-HER2 therapy alone was given for the first 6 weeks ; weekly paclitaxel ( 80 mg/m(2 ) ) was then added to the regimen for a further 12 weeks , before definitive surgery was undertaken . After surgery , patients received adjuvant chemotherapy followed by the same targeted therapy as in the neoadjuvant phase to 52 weeks . The primary endpoint was the rate of pathological complete response ( pCR ) , analysed by intention to treat . This trial is registered with Clinical Trials.gov , NCT00553358 . FINDINGS 154 patients received lapatinib , 149 trastuzumab , and 152 the combination . pCR rate was significantly higher in the group given lapatinib and trastuzumab ( 78 of 152 patients [ 51·3 % ; 95 % CI 43·1 - 59·5 ] ) than in the group given trastuzumab alone ( 44 of 149 patients [ 29·5 % ; 22·4 - 37·5 ] ; difference 21·1 % , 9·1 - 34·2 , p=0·0001 ) . We recorded no significant difference in pCR between the lapatinib ( 38 of 154 patients [ 24·7 % , 18·1 - 32·3 ] ) and the trastuzumab ( difference -4·8 % , -17·6 to 8·2 , p=0·34 ) groups . No major cardiac dysfunctions occurred . Frequency of grade 3 diarrhoea was higher with lapatinib ( 36 patients [ 23·4 % ] ) and lapatinib plus trastuzumab ( 32 [ 21·1 % ] ) than with trastuzumab ( three [ 2·0 % ] ) . Similarly , grade 3 liver-enzyme alterations were more frequent with lapatinib ( 27 [ 17·5 % ] ) and lapatinib plus trastuzumab ( 15 [ 9·9 % ] ) than with trastuzumab ( 11 [ 7·4 % ] ) . INTERPRETATION Dual inhibition of HER2 might be a valid approach to treatment of HER2-positive breast cancer in the neoadjuvant setting . FUNDING GlaxoSmithKline PURPOSE This is a noncomparative , r and omized , phase II trial of preoperative taxane-anthracycline in combination with trastuzumab , lapatinib , or combined trastuzumab plus lapatinib in patients with human epidermal growth factor receptor 2 ( HER2 ) -positive , stage II to IIIA operable breast cancer . The primary aim was to estimate the percentage of pathologic 
    Output:
    
Subgroup analyses indicated that the addition of chemotherapy to dual anti-HER2 therapy could greatly improve pCR in the neoadjuvant setting s. However , in the metastatic setting , similar PFS and OS were found in patients receiving dual anti-HER2 therapy with or without chemotherapy .
Dual anti-HER2 therapy was associated with more frequent adverse events than monotherapy , but no statistical differences were observed in cardiac toxicity .
Conclusions This systematic review provides a summary of all the data currently available , and confirms the benefits and risks of dual anti-HER2 therapy for HER2-positive breast cancer