The correlations between the prognosis and the expressions of Ki-67 and other emerging proteins in canine mammary gland tumors

Canine mammary gland tumors (cMGTs) are the most common neoplasms in intact female dogs and the malignant rate ranges from 41 to 53 %. The most important factors related to cMGTs are age and ovarian hormones. Early detection with subsequent therapies are essential to prevent early local recurrence or distant dissemination. However, these prognostic factors may be not always predictable if a tumor will metastasize or not. The Ki-67, a nuclear antigen, is one of the most commonly used markers to evaluate tumor proliferative activity. In this study, the WHO classification and staging system were used to classify the cMGTs. In addition, the emerging proteins including p63, KLF2, KLF4, KLF5, and KLF6 were employed to compare with histological grading, Ki-67 expression and clinical outcomes.
Current results showed that the histological grading and Ki-67 expression were highly significant associated with clinical outcomes. And the increased 40 % expression of Ki-67 had shorter survival time of patients. Moreover, we suggested that Ki-67 could be used to identify the malignancy and histological grading. Otherwise, the nuclear expression of KLF2, KLF4, KLF5, and KLF6 expression was significantly associated with the malignancy of the cMGTs (P < 0.0001). These emerging proteins, considered the important role in the cancer regulation, also showed significant associated with clinical outcomes through comparison with the expression of Ki-67.