Expression of p53 and Ki-67 in Salivary Gland Tumors

Korean Journal of Head & Neck Oncology 2006;22(1):8-14.
Published online May 30, 2006.

Hyun Jung Min;Kyung Rae Kim;Chul Won Park;Hyung Seok Lee;Seung Sam Paik;Young Ha Oh;Kyung Tae

타액선 종양에서 p53과 Ki-67의 발현

민현정;김경래;박철원;이형석;백승삼;오영하;태경

Abstract

Objectives: The p53 tumor suppressor gene has a key role in cellular control mechanisms involving apoptosis and DNA repair, leading to the G1 arrest following DNA damage. Its mutation is one of the most frequent alterations in human cancers. Ki-67 is identified in replicating cells of both benign and malignant lesions, so it can be the predictor of proliferative activity. The aim of this study is to evaluate the expression of p53 and Ki-67 in salivary gland tumors. Materials and Methods: Immunohistochemical analysis was used to detect expression of p53 and Ki-67 in paraffin-embedded samples from 31 benign and 27 malignant salivary gland tumors. Results were analyzed between benign and malignant tumors and compared with the clinical parameters such as stage and recurrence in malignant tumors.
Results
p53 overexpression was detected in 19.6% of benign tumors and 40.7% of malignant tumors, but there was no statistical significance. p53 was significantly expressed in Warthin's tumor(45.5%) compared with pleomorphic adenoma(5.9%). Only 5.9% of pleomorphic adenoma were positive for p53, while 60% of carcinoma ex pleomorphic adenoma were positive for p53. Ki-67 was expressed in 3.2% of benign tumors and 51.9% of malignant tumors, which showed significant higher expression in malignant tumors. In malignant tumors, p53 and Ki-67 expressions bore no correlation to stage and recurrence.
Conclusion
p53 overexpression is not associated with the progression of malignant tumors, and Ki-67 overexpression can be used as biologic indicator of malignant salivary gland tumors.

Key Words: p53, Ki-67, Salivary gland neoplasms