Evaluation of the serum level of high mobility group box 1 protein in benign and malignant salivary gland tumors

Despite a low prevalence, salivary gland tumors (SGTs) represent a diverse set of tumors with a broad range of biologic behaviors. Implementation of early detection programs has significantly improved the outcome of treatment and patients' survival. High mobility group box 1 protein (HMGB1) may likely be a candidate for the detection of SGTs due to its background in other human tumors. This study, for the first time, aimed to investigate the clinical value of HMGB1 in patients with benign and malignant SGTs and analyze its correlation with clinicopathologic outcomes.

Using an enzyme-linked immunosorbent assay (ELISA), the serum level of HMGB1 was measured in 85 patients with SGTs (30 benign and 55 malignant cases) and 85 age- and sex-matched healthy individuals.

HMGB1 levels had a significant difference between patients with SGTs and healthy controls (2041.4±787.1 pg/ml versus 536.3±374.6 pg/ml, p<0.0001) as well as those with benign and malignant tumors (1680.1±429.7 pg/ml versus 2238.6±867.2 pg/ml, p<0.0001). The serum level of HMGB1 was associated with some clinicopathologic factors, such as the size of the main tumor, clinical stage and the lymph node metastasis, but not with patients' gender, age as well as the site of the lesions.

These results suggest that the serum level of HMGB1 has the potential to be a supportive diagnostic marker for SGTs and can provide a precise assessment of the tumor status. There is no published report regarding the serum level of HMGB1 in SGTs; therefore, further studies are warranted.