{"doi":"10.1093/jnci/djaf048","title":"Prevalence by therapy line and incidence of breast cancer brain metastases in 18 075 patients","abstract":"<jats:title>Abstract</jats:title>\n               <jats:sec>\n                  <jats:title>Importance</jats:title>\n                  <jats:p>Brain metastases portend poor prognosis in patients with metastatic breast cancer (MBC). Designing treatment and prevention clinical trials requires knowledge of brain metastases incidence with each line of therapy.</jats:p>\n               </jats:sec>\n               <jats:sec>\n                  <jats:title>Objectives</jats:title>\n                  <jats:p>We assessed the prevalence and cumulative incidence of brain metastases in a large MBC patient cohort by subtype and line of therapy, and the impact of HER2-low expression on prevalence.</jats:p>\n               </jats:sec>\n               <jats:sec>\n                  <jats:title>Design, Setting and Outcomes</jats:title>\n                  <jats:p>We analyzed brain metastases prevalence in patients with MBC in a nationwide electronic health record-derived de-identified database. The primary outcome was first diagnosis of brain metastases. We estimated prevalence and incidence of brain metastases by MBC subtype, including HER2-low and therapy line. We used the cumulative incidence function to estimate brain metastases risk in patients without brain metastases at initiation of systemic therapy. All P-values are 2-sided, and a P-value ≤.05 indicates statistical significance.</jats:p>\n               </jats:sec>\n               <jats:sec>\n                  <jats:title>Results</jats:title>\n                  <jats:p>Among 18 075 patients with MBC, 1102 (6.1%) had at least 1 brain metastasis at first-line therapy initiation. For the remaining 16 973 patients, cumulative incidence of brain metastases at 60 months was 10% in patients with hormone receptor-positive (HR+)/HER2− disease, 23% for HR+/HER2+ disease, 34% for HR−/HER2+ disease, and 22% for triple-negative breast cancer (TNBC). HER2-low expression within HR+/HER2− and TNBC subtypes had no impact on brain metastases incidence. Brain metastases prevalence increased per line of therapy for patients with all breast cancer subtypes.</jats:p>\n               </jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions</jats:title>\n                  <jats:p>Brain metastases incidence increases per line of therapy for every MBC subtype. The HER2-low biomarker does not impact brain metastases incidence within historical subtypes.</jats:p>\n               </jats:sec>","journal":"JNCI: Journal of the National Cancer Institute","year":2025,"id":600448,"datarank":0.37273599746820013,"base_score":2.4849066497880004,"endowment":2.4849066497880004,"self_citation_contribution":0.37273599746820013,"citation_network_contribution":0.0,"self_endowment_contribution":0.37273599746820013,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":11,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1539428,"name":"Thibaut Sanglier","orcid":"0000-0003-0740-2048","position":1,"is_corresponding":false},{"id":574702,"name":"José Pablo Leone","orcid":"0000-0002-8537-652X","position":2,"is_corresponding":false},{"id":1539431,"name":"Timothy K Erick","orcid":null,"position":3,"is_corresponding":false},{"id":421666,"name":"Peter Lambert","orcid":"0000-0001-9427-638X","position":4,"is_corresponding":false},{"id":1539435,"name":"Filippo Montemurro","orcid":"0000-0003-4231-2291","position":5,"is_corresponding":false},{"id":1539437,"name":"Raf Poppe","orcid":"0000-0001-9434-2674","position":6,"is_corresponding":false},{"id":1539439,"name":"Eleonora Restuccia","orcid":"0000-0001-5751-094X","position":7,"is_corresponding":false},{"id":56758,"name":"Sara M. Tolaney","orcid":"0000-0002-5940-8671","position":8,"is_corresponding":false},{"id":3753,"name":"Nancy U. Lin","orcid":"0000-0003-2263-5413","position":9,"is_corresponding":false},{"id":714161,"name":"Sarah Sammons","orcid":"0000-0003-2589-9422","position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"Prevalence by therapy line and incidence of breast cancer brain metastases in 18 075 patients","abstract":"<jats:title>Abstract</jats:title>\n               <jats:sec>\n                  <jats:title>Importance</jats:title>\n                  <jats:p>Brain metastases portend poor prognosis in patients with metastatic breast cancer (MBC). Designing treatment and prevention clinical trials requires knowledge of brain metastases incidence with each line of therapy.</jats:p>\n               </jats:sec>\n               <jats:sec>\n                  <jats:title>Objectives</jats:title>\n                  <jats:p>We assessed the prevalence and cumulative incidence of brain metastases in a large MBC patient cohort by subtype and line of therapy, and the impact of HER2-low expression on prevalence.</jats:p>\n               </jats:sec>\n               <jats:sec>\n                  <jats:title>Design, Setting and Outcomes</jats:title>\n                  <jats:p>We analyzed brain metastases prevalence in patients with MBC in a nationwide electronic health record-derived de-identified database. The primary outcome was first diagnosis of brain metastases. We estimated prevalence and incidence of brain metastases by MBC subtype, including HER2-low and therapy line. We used the cumulative incidence function to estimate brain metastases risk in patients without brain metastases at initiation of systemic therapy. All P-values are 2-sided, and a P-value ≤.05 indicates statistical significance.</jats:p>\n               </jats:sec>\n               <jats:sec>\n                  <jats:title>Results</jats:title>\n                  <jats:p>Among 18 075 patients with MBC, 1102 (6.1%) had at least 1 brain metastasis at first-line therapy initiation. For the remaining 16 973 patients, cumulative incidence of brain metastases at 60 months was 10% in patients with hormone receptor-positive (HR+)/HER2− disease, 23% for HR+/HER2+ disease, 34% for HR−/HER2+ disease, and 22% for triple-negative breast cancer (TNBC). HER2-low expression within HR+/HER2− and TNBC subtypes had no impact on brain metastases incidence. Brain metastases prevalence increased per line of therapy for patients with all breast cancer subtypes.</jats:p>\n               </jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions</jats:title>\n                  <jats:p>Brain metastases incidence increases per line of therapy for every MBC subtype. The HER2-low biomarker does not impact brain metastases incidence within historical subtypes.</jats:p>\n               </jats:sec>","is_dataset_classified":null,"base_score":2.4849066497880004,"endowment":2.4849066497880004,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"40163696","pmcid":null,"openalex_id":"https://openalex.org/W4409012733","authors":[],"funders":[],"total_grants":0,"fwci":8.3895,"citation_percentile":0.98099712,"influential_citations":0,"citation_trend":[{"year":2025,"count":5},{"year":2026,"count":6}],"oa_status":"bronze","license":"https://academic.oup.com/pages/standard-publication-reuse-rights","oa_locations":[{"url":"https://academic.oup.com/jnci/advance-article-pdf/doi/10.1093/jnci/djaf048/62822148/djaf048.pdf","host_type":"journal"},{"url":"https://academic.oup.com/jnci/advance-article-pdf/doi/10.1093/jnci/djaf048/62822148/djaf048.pdf","host_type":"publisher"},{"url":"https://academic.oup.com/jnci/article-pdf/117/8/1565/62822148/djaf048.pdf","host_type":"publisher"},{"url":"https://doi.org/10.1093/jnci/djaf048","host_type":"journal"},{"url":"https://pubmed.ncbi.nlm.nih.gov/40163696","host_type":"repository"}],"fields_of_study":["Brain Metastases and Treatment","Lung Cancer Research Studies","HER2/EGFR in Cancer Research"],"mesh_terms":["Adult","Aged","Aged, 80 and over","Brain Neoplasms","Breast Neoplasms","Female","Humans","Middle Aged","Receptors, Estrogen","Receptors, Progesterone","Incidence","Prevalence","Receptor, ErbB-2","Erb-b2 Receptor Tyrosine Kinases","Triple Negative Breast Neoplasms"],"keywords":["Medicine","Incidence (geometry)","Brain metastasis","Breast cancer","Internal medicine","Cumulative incidence","Oncology","Metastatic breast cancer","Cancer","Cohort","Disease","Metastasis","Systemic therapy"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Good health and well-being"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-07-29T13:11:19.164462Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}