Ki-67 as a prognostic factor in feline mammary carcinoma: what is the optimal cutoff value?

Soares, M., Ribeiro, R. , Carvalho, S., Peleteiro, M., Correia, J. and Ferreira, F. (2016) Ki-67 as a prognostic factor in feline mammary carcinoma: what is the optimal cutoff value? Veterinary Pathology, 53(1), pp. 37-43. (doi: 10.1177/0300985815588606) (PMID:26080833)

Abstract

Ki-67 is a nuclear protein and a proliferation marker frequently used in establishing the prognosis for breast cancer patients. To investigate the prognostic value of the Ki-67 proliferation index in female cats with mammary carcinoma, a prospective study was conducted with 96 animals. The Ki-67 index of primary tumors (n = 96) was initially determined, and whenever possible, the Ki-67 index of regional lymph node metastasis (n = 38) and distant metastasis (n = 16) was also estimated. The optimal cutoff value for the Ki-67 index was determined by univariate and multivariate analysis. Ki-67 indices ≥14% were detected in 72.9% (70 of 96) of the tumors. Tumors with a Ki-67 index ≥14% were significantly associated with large size (P = .022), poor differentiation (P = .009), presence of necrotic areas (P = .008), estrogen receptor-negative status (P < .0001), fHER2-negative status (P = .003), and shorter overall survival (P = .012). Moreover, Ki-67 expression in the primary tumor was strongly and positively correlated with both regional metastasis (P < .0001; r = 0.83) and distant metastasis (P < .0001; r = 0.83), and was significantly higher in distant metastases when compared with the primary tumor (P = .0009). A similar correlation was also observed between regional and distant metastasis (P < .0001; r = 0.75). On the basis of the above results, the authors propose the adoption of the 14% value as the optimal cutoff for Ki-67 to identify tumors with high risk of disease progression.

• Item Type: Articles
• Additional Information: This research was supported by ‘‘Fundacao para a Ciencia e Tecnologia’’ (FCT) project grant UID/CVT/00276/2013 and PhD fellowship SFRH/BD/70720/2010.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Cardoso Ribeiro, Dr Rita Claudia
• Authors: Soares, M., Ribeiro, R., Carvalho, S., Peleteiro, M., Correia, J., and Ferreira, F.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Veterinary Pathology
• Publisher: SAGE Publications
• ISSN: 0300-9858
• ISSN (Online): 1544-2217

Related URLs

• Other