2023
Phase II trial of pembrolizumab in patients with brain metastases.
Brastianos P, Kim A, Giobbie-Hurder A, Lee E, Lin N, Overmoyer B, Wen P, Nayak L, Cohen J, Dietrich J, Heist R, Krop I, Lawrence D, Mayer E, Winer E, Shih H, Oh K, Cahill D, Gerstner E, Sullivan R. Phase II trial of pembrolizumab in patients with brain metastases. Journal Of Clinical Oncology 2023, 41: 2006-2006. DOI: 10.1200/jco.2023.41.16_suppl.2006.Peer-Reviewed Original ResearchBrain metastasesPrimary endpointBenefit rateEvaluable patientsLung cancerBreast cancerTherapeutic strategiesSingle-arm phase 2 clinical trialNon-small cell lung cancerHormone receptor-positive diseaseSmall cell lung cancerPhase 2 clinical trialGrade 4 toxicityLogical therapeutic strategyRECIST 1.1 criteriaMedian overall survivalPD-1 blockadePD-1 inhibitorsPrimary efficacy endpointReceptor-positive diseasePhase II trialImmune-based strategiesTriple-negative subtypeCell lung cancerT cell cytotoxicityTucatinib vs Placebo, Both in Combination With Trastuzumab and Capecitabine, for Previously Treated ERBB2 (HER2)-Positive Metastatic Breast Cancer in Patients With Brain Metastases
Lin N, Murthy R, Abramson V, Anders C, Bachelot T, Bedard P, Borges V, Cameron D, Carey L, Chien A, Curigliano G, DiGiovanna M, Gelmon K, Hortobagyi G, Hurvitz S, Krop I, Loi S, Loibl S, Mueller V, Oliveira M, Paplomata E, Pegram M, Slamon D, Zelnak A, Ramos J, Feng W, Winer E. Tucatinib vs Placebo, Both in Combination With Trastuzumab and Capecitabine, for Previously Treated ERBB2 (HER2)-Positive Metastatic Breast Cancer in Patients With Brain Metastases. JAMA Oncology 2023, 9: 197-205. PMID: 36454580, PMCID: PMC9716438, DOI: 10.1001/jamaoncol.2022.5610.Peer-Reviewed Original ResearchConceptsErbB2-positive metastatic breast cancerMetastatic breast cancerPlacebo-combination groupPositive metastatic breast cancerNew brain lesionsBrain metastasesOverall survivalSubgroup analysisBrain lesionsBreast cancerIntracranial progression-free survivalPlacebo-controlled clinical trialIntracranial objective response rateStable brain metastasesMedian overall survivalObjective response rateProgression-free survivalExploratory subgroup analysisGreater clinical benefitCNS-PFSHER2CLIMB trialIntracranial outcomesFirst progressionMedian ageClinical benefit
2022
Corrigendum to “Tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2D metastatic breast cancer with and without brain metastases (HER2CLIMB): final overall survival analysis” [Annals of Oncology 33 (2022) 321-329]
Curigliano G, Mueller V, Borges V, Hamilton E, Hurvitz S, Loi S, Murthy R, Okines A, Paplomata E, Cameron D, Carey L, Gelmon K, Hortobagyi G, Krop I, Loibl S, Pegram M, Slamon D, Ramos J, Feng W, Winer E. Corrigendum to “Tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2D metastatic breast cancer with and without brain metastases (HER2CLIMB): final overall survival analysis” [Annals of Oncology 33 (2022) 321-329]. Annals Of Oncology 2022, 34: 630. PMID: 36564285, DOI: 10.1016/j.annonc.2022.12.005.Peer-Reviewed Original ResearchPreclinical and clinical efficacy of trastuzumab deruxtecan in breast cancer brain metastases
Kabraji S, Ni J, Sammons S, Li T, Van Swearingen AED, Wang Y, Pereslete A, Hsu L, DiPiro PJ, Lascola C, Moore H, Hughes M, Raghavendra AS, Gule-Monroe M, Murthy RK, Winer EP, Anders CK, Zhao JJ, Lin NU. Preclinical and clinical efficacy of trastuzumab deruxtecan in breast cancer brain metastases. Clinical Cancer Research 2022, 29: 174-182. PMID: 36074155, PMCID: PMC9811155, DOI: 10.1158/1078-0432.ccr-22-1138.Peer-Reviewed Original ResearchConceptsBreast cancer brain metastasesActive brain metastasesObjective response rateCNS objective response rateCancer brain metastasesBrain metastasesT-DXdPatient-derived xenograftsPDX modelsCohort studyTrastuzumab deruxtecanClinical efficacyClinical trialsHER2-positive breast cancer brain metastasesMetastatic HER2-positive breast cancerResponse rateMulti-institutional cohort studyHER2-positive breast cancerRetrospective multi-institutional cohort studyOrthotopic patient-derived xenograftsRetrospective cohort studyProspective clinical trialsSubset of patientsCentral nervous system activityPivotal clinical trialsp16INK4A-deficiency predicts response to combined HER2 and CDK4/6 inhibition in HER2+ breast cancer brain metastases
Ni J, Kabraji S, Xie S, Wang Y, Pan P, He X, Liu Z, Leone JP, Long HW, Brown MA, Winer EP, Dillon DAR, Lin NU, Zhao JJ. p16INK4A-deficiency predicts response to combined HER2 and CDK4/6 inhibition in HER2+ breast cancer brain metastases. Nature Communications 2022, 13: 1473. PMID: 35304445, PMCID: PMC8933392, DOI: 10.1038/s41467-022-29081-2.Peer-Reviewed Original ResearchConceptsPatient-derived xenograftsBrain metastasesMetastatic HER2-positive breast cancerBiomarker-driven clinical trialsBreast cancer brain metastasesHER2-positive breast cancerOrthotopic patient-derived xenograftsMajority of HER2Cancer brain metastasesCDK4/6 inhibitionProtein immunohistochemistryClinical trialsBreast cancerHER2Tumor suppressor p16INK4aPatientsMetastasisBCBMAbemaciclibTucatinibXenograftsImmunohistochemistryCancerCDK4/6Trials
2021
Tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB): final overall survival analysis
Curigliano G, Mueller V, Borges V, Hamilton E, Hurvitz S, Loi S, Murthy R, Okines A, Paplomata E, Cameron D, Carey L, Gelmon K, Hortobagyi G, Krop I, Loibl S, Pegram M, Slamon D, Ramos J, Feng W, Winer E. Tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB): final overall survival analysis. Annals Of Oncology 2021, 33: 321-329. PMID: 34954044, DOI: 10.1016/j.annonc.2021.12.005.Peer-Reviewed Original ResearchConceptsProgression-free survivalMetastatic breast cancerPlacebo-combination groupOverall survivalCombination groupBreast cancerHER2CLIMB trialBrain metastasesMedian durationSafety outcomesPrimary analysisFinal overall survival analysisHuman epidermal growth factor receptor 2 positive metastatic breast cancerPositive metastatic breast cancerMeaningful survival benefitMedian overall survivalPlacebo-controlled trialOverall study populationOverall survival analysisFinal OSMetastatic HER2Placebo combinationAdverse eventsLast patientPrespecified subgroupsSYST-06. PHASE II TRIAL OF PAXALISIB (GDC-0084) IN COMBINATION WITH TRASTUZUMAB FOR PATIENTS WITH HER2-POSITIVE BREAST CANCER BRAIN METASTASES (BCBM)
Leone J, Tayob N, Pereslete A, Ligibel J, Parsons H, Bi W, Zhao J, Winer E, Lin N. SYST-06. PHASE II TRIAL OF PAXALISIB (GDC-0084) IN COMBINATION WITH TRASTUZUMAB FOR PATIENTS WITH HER2-POSITIVE BREAST CANCER BRAIN METASTASES (BCBM). Neuro-Oncology Advances 2021, 3: iv9-iv9. DOI: 10.1093/noajnl/vdab112.034.Peer-Reviewed Original ResearchBreast cancer brain metastasesObjective response rateCohort BCohort ACNS metastasesPrimary endpointHER2-positive breast cancer brain metastasesNeuro-Oncology Brain Metastases criteriaCentral nervous system metastasesHER2-positive breast cancerPatient-derived xenografts (PDX) modelsPhase II cohortNervous system metastasesPhase II studyCancer brain metastasesPhase II trialPI3K/Akt/mTORPatient-reported outcomesPI3KBrain-penetrant inhibitorAkt/mTORMetastasis (TNM) criteriaBrain metastasesII trialMetastasis resectionHow we treat HER2-positive brain metastases
Stavrou E, Winer EP, Lin NU. How we treat HER2-positive brain metastases. ESMO Open 2021, 6: 100256. PMID: 34482180, PMCID: PMC8424223, DOI: 10.1016/j.esmoop.2021.100256.Peer-Reviewed Original ResearchConceptsHER2-positive brain metastasesHuman epidermal growth factor 2Brain metastasesAdvanced diseaseBreast cancerCentral nervous system metastasesHER2-positive breast cancerEpidermal growth factor 2Nervous system metastasesExperienced multidisciplinary teamSurvival of patientsCentral nervous system activitySite of diseaseNervous system activityUnique clinical challengesAssociated morbiditySystemic therapyGrowth factor 2Clinical challengeReview of agentsClinical scenariosMultidisciplinary teamMetastasisSystem activityDiseaseUpdated results of tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB).
Curigliano G, Mueller V, Borges V, Hamilton E, Hurvitz S, Loi S, Murthy R, Okines A, Paplomata E, Cameron D, Carey L, Gelmon K, Hortobagyi G, Krop I, Loibl S, Pegram M, Slamon D, Ramos J, Zhang C, Winer E. Updated results of tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB). Journal Of Clinical Oncology 2021, 39: 1043-1043. DOI: 10.1200/jco.2021.39.15_suppl.1043.Peer-Reviewed Original ResearchMetastatic breast cancerBrain metastasesOverall survivalTyrosine kinase inhibitorsBreast cancerPlacebo armAnalysis of OSOral tyrosine kinase inhibitorECOG performance statusPlacebo-controlled trialTotal study populationKaplan-Meier timeHER2CLIMB trialMeaningful prolongationMetastatic HER2Study medicationTolerability assessmentsMetastatic settingAdverse eventsDose modificationHazard ratioLast patientPerformance statusDisease progressionStudy population
2020
Phase II trial of carboplatin and bevacizumab in patients with breast cancer brain metastases
Leone JP, Emblem KE, Weitz M, Gelman RS, Schneider BP, Freedman RA, Younger J, Pinho MC, Sorensen AG, Gerstner ER, Harris G, Krop IE, Morganstern D, Sohl J, Hu J, Kasparian E, Winer EP, Lin NU. Phase II trial of carboplatin and bevacizumab in patients with breast cancer brain metastases. Breast Cancer Research 2020, 22: 131. PMID: 33256829, PMCID: PMC7706261, DOI: 10.1186/s13058-020-01372-w.Peer-Reviewed Original ResearchMeSH KeywordsAdultAntineoplastic Combined Chemotherapy ProtocolsBevacizumabBrainBrain NeoplasmsBreastBreast NeoplasmsCarboplatinFemaleGenotyping TechniquesHumansKaplan-Meier EstimateMagnetic Resonance ImagingMiddle AgedPolymorphism, Single NucleotideProgression-Free SurvivalTrastuzumabVascular Endothelial Growth Factor AConceptsProgression-free survivalBreast cancer brain metastasesEarly MRI changesCancer brain metastasesBrain metastasesOverall survivalMRI changesBreast cancerEastern Cooperative Oncology Group performance statusDay 1Cycle 1 day 1Cycle 1 day 8Median progression-free survivalWorse progression-free survivalRegimen warrants further investigationDurable objective responsesECOG PS 1Efficacy of bevacizumabHER2-positive diseaseProgressive brain metastasesResultsThirty-eight patientsMedian overall survivalObjective response ratePhase II trialContrast-enhanced brain MRIImpact of tucatinib on progression free survival in patients with HER2+ metastatic breast cancer and stable or active brain metastases
Bachelot T, Lin N, Murthy R, Hurvitz S, Borges V, Oliveira M, Oakman C, Khan S, Lynch C, Westbrook K, Doyle C, Reinisch M, Colleoni M, Slamon D, Hortobagyi G, Winer E, McGoldrick S, An X, Loibl S. Impact of tucatinib on progression free survival in patients with HER2+ metastatic breast cancer and stable or active brain metastases. Annals Of Oncology 2020, 31: s359-s360. DOI: 10.1016/j.annonc.2020.08.395.Peer-Reviewed Original Research53. TUCATINIB VS PLACEBO ADDED TO TRASTUZUMAB AND CAPECITABINE FOR PATIENTS WITH PREVIOUSLY TREATED HER2+ METASTATIC BREAST CANCER (MBC) WITH BRAIN METASTASES (BM) (HER2CLIMB)
Lin N, Murthy R, Anders C, Borges V, Hurvitz S, Loi S, Abramson V, Bedard P, Oliveira M, Zelnack A, DiGiovanna M, Bachelot T, Chien A, O’Regan R, Wardley A, Mueller V, Carey L, McGoldrick S, An X, Winer E. 53. TUCATINIB VS PLACEBO ADDED TO TRASTUZUMAB AND CAPECITABINE FOR PATIENTS WITH PREVIOUSLY TREATED HER2+ METASTATIC BREAST CANCER (MBC) WITH BRAIN METASTASES (BM) (HER2CLIMB). Neuro-Oncology Advances 2020, 2: ii11-ii11. PMCID: PMC7401403, DOI: 10.1093/noajnl/vdaa073.041.Peer-Reviewed Original ResearchMetastatic breast cancerBrain metastasesCNS-PFSSecond progressionControl armEfficacy analysisBrain progressionExploratory efficacy analysesMedian CNS-PFSBaseline brain MRIMedian OSOverall deathRECIST 1.1Study therapyMedian timeInvestigator's evaluationIC diseaseLocal treatmentBreast cancerBrain MRIReduced riskCapecitabineTrastuzumabTucatinibHER2Intracranial Efficacy and Survival With Tucatinib Plus Trastuzumab and Capecitabine for Previously Treated HER2-Positive Breast Cancer With Brain Metastases in the HER2CLIMB Trial
Lin NU, Borges V, Anders C, Murthy RK, Paplomata E, Hamilton E, Hurvitz S, Loi S, Okines A, Abramson V, Bedard PL, Oliveira M, Mueller V, Zelnak A, DiGiovanna MP, Bachelot T, Chien AJ, O’Regan R, Wardley A, Conlin A, Cameron D, Carey L, Curigliano G, Gelmon K, Loibl S, Mayor J, McGoldrick S, An X, Winer EP. Intracranial Efficacy and Survival With Tucatinib Plus Trastuzumab and Capecitabine for Previously Treated HER2-Positive Breast Cancer With Brain Metastases in the HER2CLIMB Trial. Journal Of Clinical Oncology 2020, 38: 2610-2619. PMID: 32468955, PMCID: PMC7403000, DOI: 10.1200/jco.20.00775.Peer-Reviewed Original ResearchConceptsHER2-positive breast cancerBrain metastasesProgression-free survivalRisk of deathBreast cancerOverall survivalControl armCNS-PFSIntracranial efficacyIntracranial progressionBaseline brain magnetic resonance imagingHuman epidermal growth factor receptor 2Intracranial objective response rateEpidermal growth factor receptor 2Brain magnetic resonance imagingMedian CNS-PFSRECIST 1.1 criteriaMedian overall survivalObjective response rateGrowth factor receptor 2Positive breast cancerFactor receptor 2Magnetic resonance imagingHER2CLIMB trialImproved antitumor activityPhase I dose-escalation trial of tucatinib in combination with trastuzumab in patients with HER2-positive breast cancer brain metastases
Filho O, Leone JP, Li T, Tan-Wasielewski Z, Trippa L, Barry WT, Younger J, Lawler E, Walker L, Freedman RA, Tolaney SM, Krop I, Winer EP, Lin NU. Phase I dose-escalation trial of tucatinib in combination with trastuzumab in patients with HER2-positive breast cancer brain metastases. Annals Of Oncology 2020, 31: 1231-1239. PMID: 32461105, DOI: 10.1016/j.annonc.2020.05.014.Peer-Reviewed Original ResearchConceptsClinical benefit rateHER2-positive brain metastasesAlanine aminotransferase elevationCohort ABrain metastasesCohort BAminotransferase elevationBreast cancerHER2-positive breast cancer brain metastasesPhase I dose-escalation trialMedian progression-free survivalBreast cancer brain metastasesCommon dose-limiting toxicityI dose-escalation trialHER2-positive breast cancerCombination of tucatinibSecondary end pointsCancer brain metastasesDose-escalation trialProgression-free survivalDose-limiting toxicityMetastatic breast cancerBrain radiationObjective responseIntracranial activityGenomic profiling of breast cancer brain metastases reveals targetable alterations.
Kabraji S, Spurr L, Hughes M, Li Y, Leone J, Garrido-Castro A, Barroso-Sousa R, Files J, Kirkner G, Johnson B, Winer E, Cherniack A, Lin N. Genomic profiling of breast cancer brain metastases reveals targetable alterations. Journal Of Clinical Oncology 2020, 38: 2525-2525. DOI: 10.1200/jco.2020.38.15_suppl.2525.Peer-Reviewed Original ResearchBreast cancer brain metastasesTumor mutation burdenCancer brain metastasesBrain metastasesTargetable alterationsGenomic alterationsDana-Farber Cancer InstituteTwo-sided Fisher's exact testPIK3CA/PTENActionable genomic alterationsFisher's exact testNumber alterationsTwo-sided MannWhitney U testPrimary tumorMetastatic tumorsMutation burdenERBB2 amplificationCancer InstituteMultiple comparison correctionCancer-related genesExact testCopy number alterationsGenomic profilingU testTucatinib versus placebo added to trastuzumab and capecitabine for patients with previously treated HER2+ metastatic breast cancer with brain metastases (HER2CLIMB).
Lin N, Murthy R, Anders C, Borges V, Hurvitz S, Loi S, Abramson V, Bedard P, Oliveira M, Zelnak A, DiGiovanna M, Bachelot T, Chien A, O'Regan R, Wardley A, Müller V, Carey L, McGoldrick S, An G, Winer E. Tucatinib versus placebo added to trastuzumab and capecitabine for patients with previously treated HER2+ metastatic breast cancer with brain metastases (HER2CLIMB). Journal Of Clinical Oncology 2020, 38: 1005-1005. DOI: 10.1200/jco.2020.38.15_suppl.1005.Peer-Reviewed Original ResearchMetastatic breast cancerProgression-free survivalObjective response rateBrain metastasesOverall survivalCNS-PFSControl armSecond progressionEfficacy analysisBrain progressionLocal treatmentBreast cancerProlongation of PFSMedian progression-free survivalExploratory efficacy analysesMedian CNS-PFSMedian overall survivalBaseline brain MRIHER2 kinase inhibitorDeath overallRECIST 1.1Study therapyFree survivalInvestigator's evaluationIC disease137O Tucatinib vs placebo added to trastuzumab and capecitabine in previously treated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB)
Curigliano G, Murthy R, Loi S, Okines A, Paplomata E, Hamilton E, Hurvitz S, Cameron D, Borges V, Bedard P, Oliveira M, Jakobsen E, Bachelot T, Shachar S, Mueller V, Carey L, Loibl S, Feng W, Walker L, Winer E. 137O Tucatinib vs placebo added to trastuzumab and capecitabine in previously treated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB). Annals Of Oncology 2020, 31: s62-s63. DOI: 10.1016/j.annonc.2020.03.238.Peer-Reviewed Original Research
2019
Tucatinib, Trastuzumab, and Capecitabine for HER2-Positive Metastatic Breast Cancer
Murthy RK, Loi S, Okines A, Paplomata E, Hamilton E, Hurvitz SA, Lin NU, Borges V, Abramson V, Anders C, Bedard PL, Oliveira M, Jakobsen E, Bachelot T, Shachar SS, Müller V, Braga S, Duhoux FP, Greil R, Cameron D, Carey LA, Curigliano G, Gelmon K, Hortobagyi G, Krop I, Loibl S, Pegram M, Slamon D, Palanca-Wessels MC, Walker L, Feng W, Winer EP. Tucatinib, Trastuzumab, and Capecitabine for HER2-Positive Metastatic Breast Cancer. New England Journal Of Medicine 2019, 382: 597-609. PMID: 31825569, DOI: 10.1056/nejmoa1914609.Peer-Reviewed Original ResearchMeSH KeywordsAgedAntineoplastic Combined Chemotherapy ProtocolsBrain NeoplasmsBreast NeoplasmsCapecitabineConsolidation ChemotherapyDiarrheaDouble-Blind MethodFemaleHumansKaplan-Meier EstimateMiddle AgedOxazolesProgression-Free SurvivalProtein-Tyrosine KinasesPyridinesQuinazolinesReceptor, ErbB-2TrastuzumabConceptsHER2-positive metastatic breast cancerProgression-free survivalPlacebo-combination groupMetastatic breast cancerElevated aminotransferase levelsBrain metastasesBreast cancerOverall survivalAminotransferase levelsMedian progression-free survivalPalmar-plantar erythrodysesthesia syndromeBetter progression-free survivalPositive metastatic breast cancerHuman epidermal growth factor receptor 2End pointEpidermal growth factor receptor 2Common adverse eventsMedian overall survivalObjective response ratePrimary end pointSecondary end pointsGrowth factor receptor 2Overall survival outcomesRisk of diarrheaFactor receptor 2A phase II study of cabozantinib alone or in combination with trastuzumab in breast cancer patients with brain metastases
Leone JP, Duda DG, Hu J, Barry WT, Trippa L, Gerstner ER, Jain RK, Tan S, Lawler E, Winer EP, Lin NU, Tolaney SM. A phase II study of cabozantinib alone or in combination with trastuzumab in breast cancer patients with brain metastases. Breast Cancer Research And Treatment 2019, 179: 113-123. PMID: 31541381, DOI: 10.1007/s10549-019-05445-z.Peer-Reviewed Original ResearchConceptsBreast cancer brain metastasesObjective response rateCNS objective response ratePhase II studyCohort 2Cohort 1BCBM patientsBrain metastasesII studyCohort 3Central nervous system (CNS) objective response rateMost common grade 3/4 adverse eventsCommon grade 3/4 adverse eventsSingle-arm phase II studyGrade 3/4 adverse eventsSecondary objectiveTolerability of cabozantinibWhole brain radiationCancer brain metastasesProgression-free survivalBreast cancer patientsTumor blood volumeCabozantinib 60RECIST 1.1STie-2Pre- and Postoperative Neratinib for HER2-Positive Breast Cancer Brain Metastases: Translational Breast Cancer Research Consortium 022
Freedman RA, Gelman RS, Agar NYR, Santagata S, Randall EC, Lopez B, Connolly RM, Dunn IF, Van Poznak CH, Anders CK, Melisko ME, Silvestri K, Cotter CM, Componeschi KP, Marte JM, Moy B, Blackwell KL, Puhalla SL, Ibrahim N, Moynihan TJ, Nangia J, Tung N, Burns R, Rimawi MF, Krop IE, Wolff AC, Winer EP, Lin NU, Consortium T. Pre- and Postoperative Neratinib for HER2-Positive Breast Cancer Brain Metastases: Translational Breast Cancer Research Consortium 022. Clinical Breast Cancer 2019, 20: 145-151.e2. PMID: 31558424, PMCID: PMC7035200, DOI: 10.1016/j.clbc.2019.07.011.Peer-Reviewed Original ResearchMeSH KeywordsAdministration, OralAdultAntineoplastic Combined Chemotherapy ProtocolsBrainBrain NeoplasmsBreastBreast NeoplasmsChemotherapy, AdjuvantCraniotomyDrug Administration ScheduleFemaleHumansMiddle AgedNeoadjuvant TherapyPilot ProjectsQuinolinesReceptor, ErbB-2Tissue DistributionTreatment OutcomeConceptsCentral nervous system penetrationCerebrospinal fluidBrain metastasesStudy treatmentDisease progressionHER2-positive breast cancer brain metastasesHER2-positive metastatic breast cancerHER2-positive brain metastasesBreast cancer brain metastasesGrade 3 diarrheaCancer brain metastasesMetastatic breast cancerCentral nervous systemResected tumor tissueBlood-based analysesNeratinib monotherapyPostoperative cyclesParenchymal tumorsStudy protocolBreast cancerTumor histopathologyPatientsNervous systemSmall cohortSurgical tissues