Conclusion: The possible roles of CD44st, CD44v5 and CD44v6 in the prognosis of head and neck cancer deserve further elucidation and evaluation with long-term patient follow-up.
Objective: Standard CD44 (CD44st), CD44 variant 5 (CD44v5) and CD44 variant 6 (CD44v6) are expressed in human malignant cells and tissues. The mechanism of their expression remains unclear, but has been reported to be associated with the progression and metastasis of malignancies. Recently, it has frequently been reported that the prognosis of head and neck cancer is associated with expression of the cell adhesion molecule CD44.
Material and methods: We investigated correlations between the soluble adhesion molecule CD44 and clinicopathologic variables, for example, age, sex, histologic grade, tumor size, lymph node status, distant metastasis and TNM stage. The pre- and post-treatment serum levels of CD44st, CD44v5 and CD44v6 were determined by means of ELISAs in 81 patients with head and neck cancer and 20 healthy volunteers (controls).
Results: In the cancer patients, the pre-treatment median serum levels of CD44st, CD44v5 and CD44v6 were 327 +/- 134, 312 +/- 118 and 211 +/ 110 ng/ml, respectively. The corresponding post-treatment levels were 185 +/- 103, 177 +/- 90 and 110 +/- 65 ng/ml. In the healthy volunteers, the median serum levels of CD44st, CD44v5 and CD44v6 were 133 +/- 40, 142 +/- 39 and 86 +/- 22 ng/ml, respectively. In the cancer patients, there was no significant correlation between the serum levels of CD44st, CD44v5 and CD44v6 and the clinicopathological variables. The pre-treatment serum levels of CD44st, CD44v5 and CD44v6 were closely associated with TNM stage (p = 0.0017, 0.0005 and 0.0046, respectively). The median pre-treatment serum levels of CD44st, CD44v5 and CD44v6 were significantly higher than those in the control group (p = 0.0002, 0.0065 and 0.0038, respectively). The median post- treatment serum levels of CD44st, CD44v5 and CD44v6 were significantly lower than the pre-treatment levels (p = 0.0003, 0.0027 and 0.0034, respectively).