E-CADHERIN LOSS AND ΔNP73L EXPRESSION IN ORAL SQUAMOUS CELL CARCINOMAS SHOWING AGGRESSIVE BEHAVIOR

Background. This article sought to investigate the existence of parameters useful for predicting lymph node metastases in cases of surgically resected oral squamous cell carcinomas (OSCCs). Methods. Fifty-eight cases were studied for E-cadherin and the truncated dominant-negative isoform of p63 (Delta Np63) with immunohistochemistry. In addition, the p63 gene expression profile was evaluated by reverse transcriptase-polymerase chain reaction (RTPCR) to disclose the presence of the truncated variant Delta Np73L. Results. E-cadherin expression was the most powerful parameter related to the presence of lymph node metastases at presentation. Twenty-four of 38 (63%) cases showing low E-cadherin expression had lymph node metastases at presentation compared with 5 of 20 (25%) (p <.01) cases showing high E-cadherin expression. The high predictive value was also maintained when a low expression of E-cadherin was associated with immunohistochemical high expression of Delta Np63. The association between low E-cadherin expression and Delta Np73L (as seen with reverse transcriptase-polymerase chain reaction) was highly predictive for developing lymph node metastases, especially in small tumors (T1\T2). When this association occurred, metastases developed in 62.5% of cases during the follow-up compared with 16% in those which did not show low E-cadherin expression and presence of Delta Np73L. Conclusion. This study shows that low E-cadherin expression is useful for predicting lymph node metastases in cases of OSCC. The predictive value is enhanced when low E-cadherin positivity is associated with Delta Np63 and Delta Np73L expression. (C)2008 Wiley Periodicals, Inc. Head Neck 30: 1475-1482. 2008