2024
Circulating tumor DNA fraction predicts residual cancer burden post-neoadjuvant chemotherapy in triple negative breast cancer
Shan N, Gould B, Wang X, Bonora G, Blenman K, Foldi J, Campos G, Walsh M, Du P, Pusztai L. Circulating tumor DNA fraction predicts residual cancer burden post-neoadjuvant chemotherapy in triple negative breast cancer. The Journal Of Liquid Biopsy 2024, 6: 100168. DOI: 10.1016/j.jlb.2024.100168.Peer-Reviewed Original ResearchTriple negative breast cancerResidual cancer burdenCirculating tumor DNANegative breast cancerPathological responsePost-NACBreast cancerPlasma circulating tumor DNATriple negative breast cancer patientsResidual cancer burden scoreCirculating tumour DNA fractionPost-neoadjuvant chemotherapyPre-NAC samplesWeekly nab-paclitaxelTumor DNA methylation profilesTumor DNA fractionHot spot mutationsYouden's J statisticNab-paclitaxelPre-NACTumor variantsTumor DNATumor fractionClinical trialsDNA methylation profilesMulti-platform biomarkers of response to an immune checkpoint inhibitor in the neoadjuvant I-SPY 2 trial for early-stage breast cancer
Campbell M, Wolf D, Yau C, Brown-Swigart L, Wulfkuhle J, Gallagher I, Zhu Z, Bolen J, Vandenberg S, Hoyt C, Mori H, Borowsky A, Sit L, Perlmutter J, Asare S, Investigators I, Nanda R, Liu M, Yee D, DeMichele A, Hylton N, Pusztai L, Berry D, Hirst G, Petricoin E, Veer L, Esserman L. Multi-platform biomarkers of response to an immune checkpoint inhibitor in the neoadjuvant I-SPY 2 trial for early-stage breast cancer. Cell Reports Medicine 2024, 101799. PMID: 39510069, DOI: 10.1016/j.xcrm.2024.101799.Peer-Reviewed Original ResearchImmune checkpoint blockadeI-SPY 2 TRIALPathological complete responseTumor microenvironmentBreast cancerAssociated with pathologic complete responseBreast cancer receptor subtypesNeoadjuvant immune checkpoint blockadePD-L1<sup>+</sup> cellsSpatial distribution of immune cellsDistribution of immune cellsEarly-stage breast cancerImmune checkpoint inhibitorsBiomarkers of responseImmune cell populationsImmune cell densityAssociated with responseImmune cell signalingCheckpoint blockadeCheckpoint inhibitorsComplete responsePretreatment biopsiesReceptor subtypesT cellsImmune cellsPathologic complete response (pCR) rates for patients with HR+/HER2- high-risk, early-stage breast cancer (EBC) by clinical and molecular features in the phase II I-SPY2 clinical trial
Huppert L, Wolf D, Yau C, Brown-Swigart L, Hirst G, Isaacs C, Pusztai L, Pohlmann P, DeMichele A, Shatsky R, Yee D, Thomas A, Nanda R, Perlmutter J, Heditsian D, Hylton N, Symmans F, Veer L, Esserman L, Rugo H. Pathologic complete response (pCR) rates for patients with HR+/HER2- high-risk, early-stage breast cancer (EBC) by clinical and molecular features in the phase II I-SPY2 clinical trial. Annals Of Oncology 2024 PMID: 39477071, DOI: 10.1016/j.annonc.2024.10.018.Peer-Reviewed Original ResearchDistant recurrence-free survivalEarly-stage breast cancerPathological complete responsePathologic complete response rateClinical/molecular featuresComplete responseER-positiveBreast cancerRate of pathological complete responseResponse to neoadjuvant chemotherapyRecurrence-free survivalI-SPY2 trialOptimal treatment selectionNeoadjuvant armER/PR statusLobular histologyNeoadjuvant chemotherapyIII diseaseImmune signaturesNegative diseaseOptimal therapyI-SPY2Excellent outcomesTreatment armsFollow-upTrends in breast cancer–specific death by clinical stage at diagnoses between 2000 and 2017
Marczyk M, Kahn A, Silber A, Rosenblit M, Digiovanna M, Lustberg M, Pusztai L. Trends in breast cancer–specific death by clinical stage at diagnoses between 2000 and 2017. Journal Of The National Cancer Institute 2024, djae241. PMID: 39348186, DOI: 10.1093/jnci/djae241.Peer-Reviewed Original ResearchBreast cancer-specific deathCancer-specific deathBreast cancerStage IAll-cause mortalityTemporal trendsStage I/II breast cancerHormone receptor-positiveNode-negative cancersPrimary tumor typeStage I/II diseaseMetastatic breast cancerStage II cancerBilateral cancerIV cancerFemale sexIV diseaseReceptor-positiveExcellent prognosisII cancerClinical stageTumor typesTreated patientsStage IIICancerThe Immune-Related 27-Gene Signature DetermaIO Predicts Response to Neoadjuvant Atezolizumab plus Chemotherapy in Triple-Negative Breast Cancer
Dugo M, Huang C, Egle D, Bermejo B, Zamagni C, Seitz R, Nielsen T, Thill M, Antón-Torres A, Russo S, Ciruelos E, Schweitzer B, Ross D, Galbardi B, Greil R, Semiglazov V, Gyorffy B, Colleoni M, Kelly C, Mariani G, Del Mastro L, Blasi O, Callari M, Pusztai L, Valagussa P, Viale G, Gianni L, Bianchini G. The Immune-Related 27-Gene Signature DetermaIO Predicts Response to Neoadjuvant Atezolizumab plus Chemotherapy in Triple-Negative Breast Cancer. Clinical Cancer Research 2024, 30: of1-of10. PMID: 39308141, PMCID: PMC11528202, DOI: 10.1158/1078-0432.ccr-24-0149.Peer-Reviewed Original ResearchPathologic complete response ratePathological complete responseTriple-negative breast cancerRNA-seqI-SPY2Immuno-oncologyBreast cancerPatients treated with pembrolizumabTumor-infiltrating lymphocyte countsPublicly available microarray dataPretreatment core biopsiesImmune checkpoint therapyRNA-seq dataPer-protocol populationAvailable microarray dataI-SPY2 trialPDL1 protein expressionNeoadjuvant atezolizumabNeoadjuvant immunotherapyPlus chemotherapyCheckpoint therapyComplete responseTriple-negativeCore biopsyRT-qPCR dataOverall Survival with Pembrolizumab in Early-Stage Triple-Negative Breast Cancer
Schmid P, Cortes J, Dent R, McArthur H, Pusztai L, Kümmel S, Denkert C, Park Y, Hui R, Harbeck N, Takahashi M, Im S, Untch M, Fasching P, Mouret-Reynier M, Foukakis T, Ferreira M, Cardoso F, Zhou X, Karantza V, Tryfonidis K, Aktan G, O'Shaughnessy J. Overall Survival with Pembrolizumab in Early-Stage Triple-Negative Breast Cancer. New England Journal Of Medicine 2024 PMID: 39282906, DOI: 10.1056/nejmoa2409932.Peer-Reviewed Original ResearchEarly-stage triple-negative breast cancerTriple-negative breast cancerPembrolizumab-chemotherapy groupPlacebo-chemotherapy groupCycles of pembrolizumabPathological complete responseEvent-free survivalOverall survivalBreast cancerAdjuvant pembrolizumabComplete responseSafety profile of pembrolizumabData cutoff dateUntreated stage IIPlatinum-containing chemotherapyMedian follow-upEstimate overall survivalSecondary end pointsEpirubicin-cyclophosphamideNeoadjuvant pembrolizumabNeoadjuvant therapyDoxorubicin-cyclophosphamideNeoadjuvant chemotherapyDefinitive surgeryPembrolizumabDatopotamab–deruxtecan in early-stage breast cancer: the sequential multiple assignment randomized I-SPY2.2 phase 2 trial
Khoury K, Meisel J, Yau C, Rugo H, Nanda R, Davidian M, Tsiatis B, Chien A, Wallace A, Arora M, Rozenblit M, Hershman D, Zimmer A, Clark A, Beckwith H, Elias A, Stringer-Reasor E, Boughey J, Nangia C, Vaklavas C, Omene C, Albain K, Kalinsky K, Isaacs C, Tseng J, Roussos Torres E, Thomas B, Thomas A, Sanford A, Balassanian R, Ewing C, Yeung K, Sauder C, Sanft T, Pusztai L, Trivedi M, Outhaythip A, Li W, Onishi N, Asare A, Beineke P, Norwood P, Brown-Swigart L, Hirst G, Matthews J, Moore B, Fraser Symmans W, Price E, Beedle C, Perlmutter J, Pohlmann P, Shatsky R, DeMichele A, Yee D, van ‘t Veer L, Hylton N, Esserman L. Datopotamab–deruxtecan in early-stage breast cancer: the sequential multiple assignment randomized I-SPY2.2 phase 2 trial. Nature Medicine 2024, 1-9. PMID: 39277671, DOI: 10.1038/s41591-024-03266-2.Peer-Reviewed Original ResearchBreast cancerLikelihood of pathologic complete responseTreatment strategiesPathologic complete response rateEarly-stage breast cancerEarly surgical resectionTaxane-based regimenComplete response ratePathological complete responsePhase 2 trialBreast cancer subtypesEffective personalized treatmentHigh-risk stageMagnetic resonance imagingComplete responseDoxorubicin-cyclophosphamideNeoadjuvant treatmentSurgical resectionOcular eventsEfficacy analysisPrimary endpointTumor subtypesNew agentsCancer subtypesPatientsPhosphoenolpyruvate carboxykinase-2 (PCK2) is a therapeutic target in triple-negative breast cancer
Gunasekharan V, Lin H, Marczyk M, Rios-Hoyo A, Campos G, Shan N, Ahmed M, Umlauf S, Gareiss P, Raaisa R, Williams R, Cardone R, Siebel S, Kibbey R, Surovtseva Y, Pusztai L. Phosphoenolpyruvate carboxykinase-2 (PCK2) is a therapeutic target in triple-negative breast cancer. Breast Cancer Research And Treatment 2024, 208: 657-671. PMID: 39177932, DOI: 10.1007/s10549-024-07462-z.Peer-Reviewed Original ResearchMetabolic fluxTriple-negative breast cancerReduced metabolic fluxMDA-MB-231 cellsCell growth in vitroEnzyme assays in vitroMDA-MB-231Potential small molecule inhibitorsPyruvate carboxylaseGrowth in vitroSmall molecule inhibitorsIn silico screeningEnzyme assaysAssay in vitroEnzymatic assayCell lines in vitroEnzyme activityGrowth inhibitory activityBT-549Breast cancerIn vitro screeningBreast cell lines in vitroPhosphoenolpyruvateSignificant growth inhibitory activityLines in vitroAcademic Uphill Battle to Personalize Treatment for Patients With Stage II/III Triple-Negative Breast Cancer
Kok M, Gielen R, Adams S, Lennerz J, Sharma P, Loibl S, Reardon E, Sonke G, Linn S, Delaloge S, Lacombe D, Robinson T, Badve S, Martin M, Balko J, Ignatiadis M, Curigliano G, Wolff A, Mittendorf E, Loi S, Pusztai L, Tolaney S, Salgado R. Academic Uphill Battle to Personalize Treatment for Patients With Stage II/III Triple-Negative Breast Cancer. Journal Of Clinical Oncology 2024, 42: 3523-3529. PMID: 39038259, DOI: 10.1200/jco.24.00372.Peer-Reviewed Original ResearchPeripheral blood immune parameters, response, and adverse events after neoadjuvant chemotherapy plus durvalumab in early-stage triple-negative breast cancer
Foldi J, Blenman K, Marczyk M, Gunasekharan V, Polanska A, Gee R, Davis M, Kahn A, Silber A, Pusztai L. Peripheral blood immune parameters, response, and adverse events after neoadjuvant chemotherapy plus durvalumab in early-stage triple-negative breast cancer. Breast Cancer Research And Treatment 2024, 208: 369-377. PMID: 39002068, DOI: 10.1007/s10549-024-07426-3.Peer-Reviewed Original ResearchImmune-related adverse eventsTriple-negative breast cancerAssociated with pathological responsePathological complete responseNeoadjuvant chemotherapyCytokine levelsPathological responseAdverse eventsBreast cancerEarly-stage triple-negative breast cancerPatients treated with immune checkpoint inhibitorsB cell clonal expansionMeasured serum cytokine levelsImmune checkpoint inhibitorsGM-CSF levelsPeripheral blood cytokine levelsBlood cytokine levelsSerum cytokine levelsB cell receptorMagnetic bead panelBenjamini-Hochberg correctionSample of patientsImmunoSEQ platformCheckpoint inhibitorsComplete responseCompletion Rate and Positive Results Reporting Among Immunotherapy Trials in Breast Cancer, 2004-2023
Mariani M, Viale G, Galbardi B, Licata L, Bosi C, Dugo M, Notini G, Naldini M, Callari M, Criscitiello C, Pusztai L, Bianchini G. Completion Rate and Positive Results Reporting Among Immunotherapy Trials in Breast Cancer, 2004-2023. JAMA Network Open 2024, 7: e2423390. PMID: 39028669, PMCID: PMC11259908, DOI: 10.1001/jamanetworkopen.2024.23390.Peer-Reviewed Original ResearchConceptsCross-sectional studyPhase III trialsIII trialsBreast cancerImmunotherapy trialsLandscape of breast cancerPhase II studyPhase II trialPhase I trialSingle-center studySingle-center trialCancer immunotherapy trialsBreast cancer trialsPatient confidenceMain OutcomesFisher's exact testImmuno-oncology trialsTrial featuresProportion of trialsCompletion ratesAdjuvant settingPhase IIReport outcomesII trialPositive resultsNeoadjuvant pembrolizumab plus chemotherapy/adjuvant pembrolizumab for early-stage triple-negative breast cancer: quality-of-life results from the randomized KEYNOTE-522 study
Dent R, Cortés J, Pusztai L, McArthur H, Kümmel S, Bergh J, Denkert C, Park Y, Hui R, Harbeck N, Takahashi M, Untch M, Fasching P, Cardoso F, Haiderali A, Jia L, Nguyen A, Pan W, O'Shaughnessy J, Schmid P. Neoadjuvant pembrolizumab plus chemotherapy/adjuvant pembrolizumab for early-stage triple-negative breast cancer: quality-of-life results from the randomized KEYNOTE-522 study. Journal Of The National Cancer Institute 2024, 116: 1654-1663. PMID: 38913881, PMCID: PMC11461162, DOI: 10.1093/jnci/djae129.Peer-Reviewed Original ResearchEarly-stage triple-negative breast cancerTriple-negative breast cancerLS mean changeBaseline to weekPatient-reported outcomesAdjuvant pembrolizumabBetween-group differencesKEYNOTE-522Neoadjuvant phaseAdjuvant phaseBreast cancerMean changePathological complete responseEvent-free survivalQuality-of-life resultsNeoadjuvant pembrolizumabPatient-reported outcome assessmentsComplete responseNeoadjuvant chemotherapyEORTC QLQ-30PembrolizumabQuality-of-lifeSecondary objectivesQLQ-30PlaceboPhase III Randomized, Placebo-Controlled Trial of Endocrine Therapy ± 1 Year of Everolimus in Patients With High-Risk, Hormone Receptor–Positive, Early-Stage Breast Cancer
Chavez-MacGregor M, Miao J, Pusztai L, Goetz M, Rastogi P, Ganz P, Mamounas E, Paik S, Bandos H, Razaq W, O'Dea A, Kaklamani V, Silber A, Flaum L, Andreopoulou E, Wendt A, Carney J, Sharma P, Gralow J, Lew D, Barlow W, Hortobagyi G. Phase III Randomized, Placebo-Controlled Trial of Endocrine Therapy ± 1 Year of Everolimus in Patients With High-Risk, Hormone Receptor–Positive, Early-Stage Breast Cancer. Journal Of Clinical Oncology 2024, 42: 3012-3021. PMID: 38833643, DOI: 10.1200/jco.23.02344.Peer-Reviewed Original ResearchInvasive disease-free survivalHormone receptor-positiveEndocrine therapyOverall survivalBreast cancerHazard ratioReceptor-positiveHigh riskSubset analysisHormone receptor-positive metastatic breast cancerRisk groupsHormone receptor-positive BCEarly-stage breast cancerStratified log-rank testProgression-free survivalEfficacy of everolimusDisease-free survivalMetastatic breast cancerPlacebo-controlled trialSecondary end pointsLog-rank testHighest grade 3Treatment completion ratesPhase IIIEverolimus armPre-treatment amino acids and risk of paclitaxel-induced peripheral neuropathy in SWOG S0221
Chen C, Zirpoli G, Budd G, Barlow W, Pusztai L, Hortobagyi G, Albain K, Godwin A, Thompson A, Henry N, Ambrosone C, Stringer K, Hertz D. Pre-treatment amino acids and risk of paclitaxel-induced peripheral neuropathy in SWOG S0221. Cancer Chemotherapy And Pharmacology 2024, 94: 311-321. PMID: 38814343, DOI: 10.1007/s00280-024-04680-6.Peer-Reviewed Original ResearchCIPN severityPeripheral neuropathyPaclitaxel-induced peripheral neuropathyEarly-stage breast cancerTrial of patientsBackgroundChemotherapy-induced peripheral neuropathyBody mass indexSerum amino acid concentrationsOver-representation analysisDebilitating neurotoxicityPaclitaxel scheduleAnti-cancer agentsBreast cancerSelf-reported raceMass indexMetabolic pathways of amino acidsSerum concentrationsInverse associationAmino acid metabolic pathwaysPaclitaxelPrimary analysisBonferroni correctionTreatment limitationsS0221CIPNCorrelation of serum anti-Müllerian hormone (AMH) levels on identification of premenopausal patients (pts) with hormone receptor positive (HR+), HER2-negative, node-positive breast cancer most likely to benefit from adjuvant chemotherapy in SWOG S1007 (RxPONDER).
Kalinsky K, Barlow W, Pathak H, Gralow J, Albain K, Hayes D, Lin N, Perez E, Goldstein L, Chia S, Rastogi P, Schott A, Shak S, Tripathy D, Hortobagyi G, Meric-Bernstam F, Sharma P, Pusztai L, Thompson A, Godwin A. Correlation of serum anti-Müllerian hormone (AMH) levels on identification of premenopausal patients (pts) with hormone receptor positive (HR+), HER2-negative, node-positive breast cancer most likely to benefit from adjuvant chemotherapy in SWOG S1007 (RxPONDER). Journal Of Clinical Oncology 2024, 42: 505-505. DOI: 10.1200/jco.2024.42.16_suppl.505.Peer-Reviewed Original ResearchInvasive disease-free survivalAnti-Mullerian hormoneFollicular stimulating hormoneAnti-Mullerian hormone levelsPremenopausal patientsRecurrence scoreChemotherapy benefitLuteinizing hormoneHormone levelsInhibin BBreast cancerBenefit of endocrine therapyNode-positive breast cancerPhase 3 randomized trialFluorescent bead-based immunoassayDisease-free survivalInvasive breast cancerNormal ovarian reserveSelf-reported menopausal statusSerum anti-Mullerian hormoneBaseline serum samplesSelection of patientsSerum hormone levelsBaseline hormone levelsUniversity of Kansas Medical CenterElucidating the immune active state of HR+HER2- MammaPrint High 2 early breast cancer.
Cobain E, Pusztai L, Graham C, Whitworth P, Beitsch P, Osborne C, Layeequr Rahman R, Johnson N, Brufsky A, Mahtani R, Gadi V, Hoskins K, Linden H, Mukhtar R, Esserman L, Haan J, Quinn K, Menicucci A, Audeh M, O'Shaughnessy J. Elucidating the immune active state of HR+HER2- MammaPrint High 2 early breast cancer. Journal Of Clinical Oncology 2024, 42: 506-506. DOI: 10.1200/jco.2024.42.16_suppl.506.Peer-Reviewed Original ResearchEarly-stage breast cancerAntigen presenting cellsImmune cell frequenciesImmune activation stateT cellsAntigen presentationB cellsBreast cancerResponse rate to neoadjuvant chemotherapyCell frequencyRate to neoadjuvant chemotherapyResponse rates to immunotherapyRisk of distant recurrenceCD4+ memory T cellsHigh-risk early-stage breast cancerCD8+ T cellsAntigen processingI-SPY 2Major histocompatibilityTumor-infiltrating lymphocytesMemory T cellsIncreased antigen presentationMemory B cellsActivated dendritic cellsImmune therapy responseCorrelation of hormone receptor positive HER2-negative/MammaPrint high-2 breast cancer with triple negative breast cancer: Results from gene expression data from the ISPY2 trial.
Rios-Hoyo A, Xiong K, Marczyk M, García-Millán R, Wolf D, Huppert L, Nanda R, Yau C, Hirst G, van 't Veer L, Esserman L, Pusztai L. Correlation of hormone receptor positive HER2-negative/MammaPrint high-2 breast cancer with triple negative breast cancer: Results from gene expression data from the ISPY2 trial. Journal Of Clinical Oncology 2024, 42: 573-573. DOI: 10.1200/jco.2024.42.16_suppl.573.Peer-Reviewed Original ResearchGene expression dataGene expression analysisExpression dataExpressed genesExpression analysisTriple-negativeDistance analysisPathway analysisDifferential gene expression analysisCell cycle pathwayGene set enrichment analysisBreast cancerIngenuity Pathway AnalysisRate of pathological complete responseHigh-risk stage IIGlucocorticoid receptor signalingTriple negative breast cancerCycle pathwayPathological complete responseDNA repairEnrichment analysisOptimal treatment strategyNegative breast cancerI-SPY2 trialGenesIncidence and time to onset of immunotherapy-related adrenal insufficiency in the I-SPY2 trial.
Nanda R, Cohen R, Quandt Z, Basu A, Yau C, Chien A, Pusztai L, Han H, Stringer-Reasor E, Isaacs C, Hershman D, Shatsky R, Perlmutter J, Yee D, DeMichele A, van 't Veer L, Hylton N, Esserman L, Rugo H. Incidence and time to onset of immunotherapy-related adrenal insufficiency in the I-SPY2 trial. Journal Of Clinical Oncology 2024, 42: 584-584. DOI: 10.1200/jco.2024.42.16_suppl.584.Peer-Reviewed Original ResearchImmune-related adverse eventsImmune checkpoint inhibitorsEarly breast cancerIncidence of AIAdrenal insufficiencyI-SPY2Advanced diseaseBreast cancerRisk of immune-related adverse eventsHigh-risk early breast cancerImmune checkpoint inhibitor doseTriple-negative breast cancerAnti-LAG-3Approval of pembrolizumabEvaluate novel agentsICI-based therapyWeekly x 4Rate of adrenal insufficiencyPhase 2 trialI-SPY2 trialTime to onsetAge of ptsCheckpoint inhibitorsNeoadjuvant settingWeekly paclitaxelDevelopment and validation of RSClin N+ tool for hormone receptor-positive (HR+), HER2-negative (HER2-), node-positive breast cancer.
Pusztai L, Hoag J, Albain K, Barlow W, Stemmer S, Meisner A, Hortobagyi G, Shak S, Hayes D, Rae J, Baehner F, Sharma P, Kalinsky K. Development and validation of RSClin N+ tool for hormone receptor-positive (HR+), HER2-negative (HER2-), node-positive breast cancer. Journal Of Clinical Oncology 2024, 42: 508-508. DOI: 10.1200/jco.2024.42.16_suppl.508.Peer-Reviewed Original ResearchChemoendocrine therapyRecurrence scoreClinicopathological factorsBreast cancerPostmenopausal patientsNode-negative breast cancerNode-positive breast cancerHormone receptor-positiveNode-positive diseaseHR+/HER2- breast cancerRisk estimatesHigh-risk patientsEstimating 5-year riskEstimation of recurrence riskLikelihood ratioPremenopausal patientsHER2-negativeReceptor-positiveChemotherapy benefitEndocrine therapyMenopausal statusRisk patientsInvasive diseasePrognostic informationPostmenopausal modelPopulation attributable fraction of reproductive factors in triple negative breast cancer by race.
Jaber Chehayeb R, Odzer N, Albany R, Phipps A, Meisner A, Pusztai L. Population attributable fraction of reproductive factors in triple negative breast cancer by race. Journal Of Clinical Oncology 2024, 42: 10522-10522. DOI: 10.1200/jco.2024.42.16_suppl.10522.Peer-Reviewed Original ResearchPopulation-attributable fractionAA womenIncidence of triple negative breast cancerPooled odds ratioOdds ratioWhite womenTriple negative breast cancerNon-Hispanic White (WhiteRelative riskRace-specific odds ratiosBreast cancerIncidence rates of triple negative breast cancerEstimates of relative riskContribution of multiple risk factorsTNBC incidenceRelevant case-control studiesPopulation attributable fractionRisk factorsYounger ageNegative breast cancerCase-control studyMultiple risk factorsBreastfeeding uptakeAttributable fractionLevin's formula