Treatment results of oral verrucous carcinoma and its biological behavior.

The biologic behavior of and optimal treatment for oral verrucous carcinoma (VC) remain controversial. We analyzed the clinicopathological characteristics of 12 patients with oral VC. Immunohistochemical techniques were used to evaluate p53 protein, CD44 variant 9, and proliferating cell nucleus antigen. The TNM classification (UICC, 1997) was T1 in 1 patient, T2 in 3, T3 in 4, and T4 in 4. All patients were classified as N0M0. Four patients were treated by surgery alone and 8 by surgery after chemotherapy, radiotherapy, or both. After surgery, two patients had primary recurrence of disease. Immunohistochemically, the proliferative activity of tumor cells as evaluated by proliferating cell nuclear antigen labeling index and p53 protein expression was similar in VC and well-differentiated squamous cell carcinoma. However, CD44 varient 9 expression was positive in 8 of 10 VC, suggesting that oral VC is associated with a low risk of lymph node metastasis. Positive CD44 variant 9 expression by most oral VCs, indicating a low risk of cervical lymph node metastasis, suggests that most cases can be controlled by surgical intervention.