Role of Ki-67 and Annexin V in the Biological Behavior of Salivary Gland Tumors: Insights into Proliferation and Apoptosis

Salivary gland tumors have diverse biological behaviors, and the exact molecular factors underlying their pathogenesis remain unclear. The expression of Annexin V and its potential association with Ki-67 in these tumors has not been explored. Therefore, this study aimed to evaluate the immunohistochemical expression of Ki-67 and Annexin V and to assess their relationship in salivary gland tumors. This study included 45 formalin-fixed, paraffin-embedded blocks (5 normal salivary gland tissues, 10 pleomorphic adenomas, 10 Warthin tumors, 10 mucoepidermoid carcinomas, and 10 adenoid cystic carcinomas). Immunohistochemical staining for Ki-67 and Annexin V was performed and evaluated semi-quantitatively. Depending on the results of the normality test, one-way ANOVA or the Kruskal-Wallis H test was used for group comparisons. Spearman’s rho test was used to assess correlations among the markers under study. A p-value < 0.05 was considered statistically significant. Both markers and their ratio showed statistically significant differences among the groups (p-value < 0.001). Normal salivary gland tissue and pleomorphic adenoma showed negative Ki-67 expression, whereas Warthin tumor, mucoepidermoid carcinoma, and adenoid cystic carcinoma showed weak proliferation indices. Annexin V expression was highest in the normal salivary gland tissue. Within individual tumor types, Ki-67 and Annexin V exhibited no significant correlation. The combined evaluation of Ki-67 and Annexin V expression, along with their relationship, may provide preliminary insights into the biological behavior of salivary gland tumors and warrant further clinicopathological investigation.