Low expression of CD40L in tumor-free lymph node of oral cavity cancer related with poor prognosis.

BACKGROUND: Recently, the genetic alterations associated with tumor progression and impaired host immunity against transformed cells draw increased attention. Here, we characterized the differential gene expression patterns and protein expression in tumor-free lymph node from recurrent and non-recurrent tumors to identify independent prognostic markers for oral squamous cell carcinoma (OSCC).

METHODS: A cDNA microarray analysis was performed to identify the differentially expressed genes in regional tumor-free lymph nodes from OSCC patients with and without recurrence. Then, the protein expression of the selected genes was analyzed by immunohistochemistry in 60 OSCC patients to determine their association with survival.

RESULTS: Widespread down-regulation of genes involved in antigen processing and recognition in lymph nodes was a distinctive feature. In univariate Kaplan-Meier analysis, lower expression of CD40L and CD80 in tumor-free lymph nodes was significantly correlated with poorer survival. In multivariate Cox regression analysis, CD40L was identified as an independent prognostic marker of disease-free survival.

CONCLUSION: Our data indicate that impaired host immunity (decreased CD40L expression) along with the TNM staging might be an important factor determining the prognosis of OSCC.