Primary tumor-associated expression of CXCR4 predicts formation of local and systemic recurrency in head and neck squamous cell carcinoma.

Objectives: Despite modern treatment regimens, overall survival in head and neck squamous cell carcinomas (HNSCC) is less than 50% due to local and systemic disease recurrency. The current study aims to identify molecular markers in primary tumor specimens that predict the risk for local and systemic recurrency at the time of initial diagnosis.

Methods: The study included clinic-pathological data of 1,057 HNSCC. MMP2/9, TIMP1/2, CXCR4, and CXCL12 immunohistochemistry was done in 150 randomly selected specimens. For statistics, we employed Chi square, Fisher exact, and Student's t-test. Overall survival (OS) was calculated by Kaplan-Meier and log-rank test. Prognostic variables were subsequently evaluated by Cox regression for forward selection.

Results: CXCR4 positive specimens demonstrated a significant increased risk for tumor recurrency associated death (rT: HR 10.07; p=0.001 / rN: HR 5.04; p=0.013 / rM: HR 2.49; p=0.029) when compared with their unaltered counterparts. Expression of MMP9, TIMP2, CXCR4, and CXCL12 was significantly increased in distant metastasized patients (p<0.0001) and showed significant cross-correlation. In addition, CXCR4 positivity was associated with an increased risk to die due to enhanced T or N status (T1/2 vs. T3/4: HR 5.78; p=0.017; N0 vs. N+: HR 5.18; p=0.033).

Conclusion: CXCR4 positivity in tumor samples at initial diagnosis were associated with reduced overall survival, in particular with respect to increasing T/N status, local and systemic recurrency.