The prevalence and prognostic value of CD168 in early-stage oral squamous cell carcinoma

OBJECTIVE: CD168 has been established as a negative prognostic marker in various tumor entities leading to a poor prognosis. Regarding OSCC, there is a lack of comprehensive studies that examine the correlation between CD168 expression and clinical outcome, hindering the implementation of this prognostic factor into clinical practice. MATERIALS AND METHODS: This retrospective analysis included all patients with primary pT1 and pT2 pN0 OSCC who received surgical therapy without the need for adjuvant therapy (pN0, M0, R0) over a seven-year long period. Immunohistochemical staining for CD168 and Mib/Ki67 was evaluated using tissue microarrays of primary tumors and correlated with clinical outcome. A cut-off value for CD168 expression of ≥10 % was considered as positive. RESULTS: A total of 139 patients (male: 91 (65.5 %), female: 48 (34.5 %)) with a mean age of 61.2 years were included (mean follow-up: 62.6 months). CD168 expression was evident in 35 (25.2 %) tumors leading to higher levels of Mib/Ki67 positivity (p < 0.001). Tumor biopsies of stage T2 OSCC stained positive for CD168 more frequently when compared to T1 tumors (p = 0.002). Tumors with CD168 expression ≥ 10 % had a significantly lower OS (p < 0.001) and RFS (p = 0.011) compared to patients with lower expression. Multivariate Cox regression identified CD168 status as a risk factor for OS (HR 2.10, CI: 1.06-4.14; p = 0.033). CONCLUSION: Our results demonstrate a significant proportion of CD168-positive tumors in OSCC and suggest an impact on prognosis, particularly with regard to OS.