Lluch, AnaBarrios, Carlos HTorrecillas, LauraRuiz-Borrego, ManuelBines, JoseSegalla, JoseGuerrero-Zotano, ÁngelGarcía-Sáenz, Jose ATorres, Robertode la Haba, JuanGarcía-Martínez, ElenaGómez, Henry LLlombart, AntonioBofill, Javier SalvadorBaena-Cañada, José MBarnadas, AgustíCalvo, LourdesPérez-Michel, LauraRamos, ManuelFernández, IsauraRodríguez-Lescure, ÁlvaroCárdenas, JesúsVinholes, JefersonMartínez de Dueñas, EduardoGodes, Maria JSeguí, Miguel AAntón, AntonioLópez-Álvarez, PilarMoncayo, JorgeAmorim, GilbertoVillar, EstherReyes, SalvadorSampaio, CarlosCardemil, BernarditaEscudero, Maria JBezares, SusanaCarrasco, EvaMartín, MiguelGEICAM Spanish Breast Cancer GroupCIBOMA (Iberoamerican Coalition for Research in Breast Oncology)LACOG (Latin American Cooperative Oncology Group)2023-02-082023-02-082019-12-05http://hdl.handle.net/10668/14792Operable triple-negative breast cancers (TNBCs) have a higher risk of relapse than non-TNBCs with standard therapy. The GEICAM/2003-11_CIBOMA/2004-01 trial explored extended adjuvant capecitabine after completion of standard chemotherapy in patients with early TNBC. Eligible patients were those with operable, node-positive-or node negative with tumor 1 cm or greater-TNBC, with prior anthracycline- and/or taxane-containing chemotherapy. After central confirmation of TNBC status by immunohistochemistry, patients were randomly assigned to either capecitabine or observation. Stratification factors included institution, prior taxane-based therapy, involved axillary lymph nodes, and centrally determined phenotype (basal v nonbasal, according to cytokeratins 5/6 and/or epidermal growth factor receptor positivity by immunohistochemistry). The primary objective was to compare disease-free survival (DFS) between both arms. Eight hundred seventy-six patients were randomly assigned to capecitabine (n = 448) or observation (n = 428). Median age was 49 years, 55.9% were lymph node negative, 73.9% had a basal phenotype, and 67.5% received previous anthracyclines plus taxanes. Median length of follow-up was 7.3 years. DFS was not significantly prolonged with capecitabine versus observation [hazard ratio (HR), 0.82; 95% CI, 0.63 to 1.06; P = .136]. In a preplanned subgroup analysis, nonbasal patients seemed to derive benefit from the addition of capecitabine with a DFS HR of 0.53 versus 0.94 in those with basal phenotype (interaction test P = .0694) and an HR for overall survival of 0.42 versus 1.23 in basal phenotype (interaction test P = .0052). Tolerance of capecitabine was as expected, with 75.2% of patients completing the planned 8 cycles. This study failed to show a statistically significant increase in DFS by adding extended capecitabine to standard chemotherapy in patients with early TNBC. In a preplanned subset analysis, patients with nonbasal phenotype seemed to obtain benefit with capecitabine, although this will require additional validation.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/AdultAgedAntimetabolites, AntineoplasticCapecitabineChemotherapy, AdjuvantDisease-Free SurvivalFemaleHumansMiddle AgedNeoadjuvant TherapyTriple Negative Breast NeoplasmsYoung Adultresearch article31804894open access10.1200/JCO.19.009041527-7755PMC6968797https://doi.org/10.1200/jco.19.00904https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6968797/pdf