{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T11:53:32Z","timestamp":1785412412113,"version":"3.56.0"},"reference-count":36,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T00:00:00Z","timestamp":1784160000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003593","name":"National Council for Scientific and Technological Development","doi-asserted-by":"publisher","award":["305420\/2013-5"],"award-info":[{"award-number":["305420\/2013-5"]}],"id":[{"id":"10.13039\/501100003593","id-type":"DOI","asserted-by":"publisher"}]},{"award":["305420\/2013-5"],"award-info":[{"award-number":["305420\/2013-5"]}],"id":[{"id":"https:\/\/ror.org\/03swz6y49","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Animals"],"abstract":"<jats:p>CMTs are biologically heterogeneous neoplasms for which reliable prognostic biomarkers remain limited. This study investigated the clinical significance of serum cancer antigen 15-3 (CA 15-3) and the immunohistochemical expression of Ki-67 and cyclooxygenase-2 (COX-2) in CMTs. Fifty-four female dogs with histologically confirmed CMTs and twelve healthy controls were prospectively evaluated. Serum CA 15-3 concentrations were measured before surgery and at 21 and 90 days post-mastectomy, while Ki-67 and COX-2 expression were assessed in tumor tissues. CA 15-3 was undetectable in controls and significantly higher in malignant than benign neoplasms (p &lt; 0.05), with moderate correlations with clinical stage (s = 0.59), histological grade (s = 0.64), and the number of nodules (s = 0.42). Levels remained elevated in advanced stages despite surgery. ROC analysis identified a CA 15-3 cutoff of 3.01 IU\/mL (AUC = 0.92) for discriminating malignant from benign tumors. Ki-67 correlated with histological grade (\u03c1 = 0.41) but showed limited prognostic accuracy (AUC = 0.63). COX-2 expression lacked significant associations and showed poor discriminatory power (AUC = 0.44). Survival analyses did not identify significant differences among groups. Principal component analysis demonstrated clustering of aggressive CMTs according to biomarker profile. These findings suggest that serum CA 15-3 may represent a useful adjunct prognostic biomarker in canine mammary oncology, while the combination of serum and tissue biomarkers may improve prognostic stratification and may guide therapeutic decision-making in veterinary oncology. These findings support the growing role of biomarker panels in the clinical management of CMTs.<\/jats:p>","DOI":"10.3390\/ani16142208","type":"journal-article","created":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T06:49:36Z","timestamp":1784184576000},"page":"2208","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Integrated Biomarker Assessment for Prognosis in Canine Mammary Carcinomas: Complementary Roles of Serum CA 15-3 and Immunohistochemistry Ki-67, and COX-2"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6363-6952","authenticated-orcid":false,"given":"Breno Queiroz","family":"Pinheiro","sequence":"first","affiliation":[{"name":"Laboratory of Carnivore Reproduction, Faculty of Veterinary Medicine, State University of Cear\u00e1 (UECE), Fortaleza 60714-903, CE, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1420-6627","authenticated-orcid":false,"given":"Marcely Braga de","family":"Albuquerque","sequence":"additional","affiliation":[{"name":"Laboratory of Carnivore Reproduction, Faculty of Veterinary Medicine, State University of Cear\u00e1 (UECE), Fortaleza 60714-903, CE, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-1074-8597","authenticated-orcid":false,"given":"Francisco Emanuel Pinheiro","family":"Cavalcante","sequence":"additional","affiliation":[{"name":"Residency Program in Small Animal Internal Medicine, Federal Rural University of the Semi-Arid Region (UFERSA), Mossor\u00f3 59625-900, RN, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0007-5070-139X","authenticated-orcid":false,"given":"Isabela Reis Barroso do","family":"Nascimento","sequence":"additional","affiliation":[{"name":"Residency Program in Veterinary Clinical Pathology, S\u00e3o Paulo State University (UNESP), Botucatu 18618-682, SP, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6727-4837","authenticated-orcid":false,"given":"Fernanda Rezende","family":"Souza","sequence":"additional","affiliation":[{"name":"Department of Pathology, Institute of Biomedical Sciences, Federal University of Alfenas (UNIFAL), Alfenas 37130-001, MG, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2412-2013","authenticated-orcid":false,"given":"Augusto Manuel Rodrigues","family":"Faustino","sequence":"additional","affiliation":[{"name":"Department of Pathology and Molecular Immunology, Institute of Biomedical Sciences Abel Salazar (ICBAS), University of Porto, 4050-313 Porto, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9793-1968","authenticated-orcid":false,"given":"L\u00facia Daniel Machado da","family":"Silva","sequence":"additional","affiliation":[{"name":"Laboratory of Carnivore Reproduction, Faculty of Veterinary Medicine, State University of Cear\u00e1 (UECE), Fortaleza 60714-903, CE, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,16]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Vazquez, E., Lipovka, Y., Cervantes-Arias, A., Garibay-Escobar, A., Haby, M.M., Queiroga, F.L., and Velazquez, C. 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