Loss of p16^INK4, alone and with overexpression of osteopontin, correlates with survival of patients with spinal metastasis from hepatocellular carcinoma

The survival of patients with hepatocellular carcinoma (HCC) has been improved with various diagnostic tools and treatment modalities. Consequently, spinal metastases from HCC are diagnosed more frequently. We investigated the clinical biomarkers of HCC patients presenting with spinal metastasis. Between January 2001 and December 2007, we recruited 30 consecutive HCC patients presenting with spinal metastasis. Their tissue samples were collected and analyzed by immunohistochemistry in a tissue microarray. A total of 16 proteins were assessed in the tissue microarray; we found that expression of p16^INK4 correlated with the survival time (log-rank test, P = 0.05), and loss of p16^INK4 was significantly associated with osteopontin overexpression (Fisher exact test: P = 0.045, logistic regression: P = 0.024, OR = 0.184, 95% CI 0.035–0.963). Patients with osteopontin (−) and with p16^INK4 (+) lived longer than patients with osteopontin (+) and with p16^INK4 (−). We found that p16^INK4 and osteopontin might be the biomarkers of patients with spinal metastasis from HCC, a more large-scaled randomized study might be required to confirm the result and study the mechanism.