{"doi":"10.1016/j.ctarc.2025.100954","title":"Trop-2 expression as a biomarker of response to sacituzumab govitecan in patients with HER2-negative metastatic breast cancer: A pilot study","abstract":"BACKGROUND: Sacituzumab govitecan (SG) is an anti-Trop-2 antibody-drug conjugate (ADC) approved for use in HER2-negative metastatic breast cancer (MBC). This study explores whether Trop-2 expression serves as a biomarker of excellent response versus non-response to sacituzumab govitecan (SG) in HER2-negative MBC. METHODS: Trop-2 expression was determined from patients with HER2-negative MBC categorized as non-responders and excellent responders to SG. Excellent response was defined by a complete or partial response and a progression-free survival (PFS) greater than the median of the cohort. Non-response was defined by progressive disease within 3 months. Trop-2 expression was determined based on percentage of cells staining and a histochemical score (H-score). RESULTS: Of the 15 patients with HER2-negative MBC (8 non-responders/7 excellent responders), the median Trop-2 expression rate was 100 % in both groups (p=0.3). H-score was also similar between the groups, with a median H-score of 270 (range 25-300) in non-responders and 280 (range 120-290) in responders (p=1.0). Lower Trop-2 percent expression was associated with shorter PFS (hazard ratio [HR]: 0.014; 95 % CI, 0-0.52; p=0.018), although Trop-2 expression by H-score was not predictive of PFS (HR: 0.994; 95 % CI, 0.987-1.002; p=0.12). One non-responder had an H-score of 25, which may represent a complete lack of Trop-2 expression. DISCUSSION: In this study, Trop-2 expression did not predict excellent response versus non-response to SG in patients with HER2-negative MBC. Low Trop-2 expression, as determined by percentage staining, was predictive of shorter PFS, although the same association was not observed using the H-score. A complete lack of Trop-2 expression may predict SG ineffective, which requires further investigation.","journal":"Cancer Treatment and Research Communications","year":2025,"id":550706,"datarank":0.16479184330021646,"base_score":1.0986122886681096,"endowment":1.0986122886681096,"self_citation_contribution":0.16479184330021646,"citation_network_contribution":0.0,"self_endowment_contribution":0.16479184330021646,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9434,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2025-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":744688,"name":"Megan Wong","orcid":"0000-0003-3799-4400","position":1,"is_corresponding":false},{"id":395167,"name":"Nora Ruel","orcid":"0000-0002-4591-3618","position":2,"is_corresponding":false},{"id":462558,"name":"Daniel Schmolze","orcid":null,"position":3,"is_corresponding":false},{"id":1446254,"name":"Min Han","orcid":"0000-0002-1497-9657","position":4,"is_corresponding":false},{"id":288920,"name":"Joanne Mortimer","orcid":"0000-0002-2935-1934","position":5,"is_corresponding":false},{"id":1153494,"name":"Christina Wei","orcid":"0000-0002-3465-6126","position":6,"is_corresponding":false},{"id":795979,"name":"Alexis LeVee","orcid":"0000-0001-9821-8144","position":0,"is_corresponding":true}],"reference_count":14,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-07-19T02:54:20.915388Z","pmid":"40516178","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":[]}