Expression of tumor-associated calcium signal transducer 2 in patients with salivary adenoid cystic carcinoma: Correlation with clinicopathological features and prognosis

Salivary adenoid cystic carcinoma (SACC) is a common salivary malignancy. The current treatment option for SACC is complete surgical excision with postoperative radiotherapy. The prognosis remains unsatisfactory, due to frequent local recurrence and distant metastases that directly reduce the overall survival time. Previous studies have shown that overexpression of tumor-associated calcium signal transducer 2 (TACSTD2) is associated with poor prognosis in various human epithelial cancers. The expression of TACSTD2 in SACC is currently unknown. The present study therefore aimed to retrospectively investigate TACSTD2 protein expression by immunohistochemistry on paraffin-embedded primary tumor tissue samples from a series of consecutive SACC patients (n=81). The correlation of TACSTD2 expression with clinicopathological variables was evaluated using either the Kruskal-Wallis or Mann-Whitney statistical tests. The survival curves were plotted using the Kaplan-Meier method. The parameters of prognostic significance found by univariate analysis were verified in a multivariate Cox regression model. Overexpression of TACSTD2 was detected in 35/81 (44%) SACC patients and was significantly associated with a decreased overall survival (P<0.01). Univariate analysis showed that TACSTD2 overexpression was correlated with TNM stage (P=0.020), local recurrence (P=0.002) and distant metastasis (P=0.001). Multivariate analyses further revealed that TACSTD2 may be an independent prognostic indicator. In conclusion, TACTSD2 could be recognized as an independent prognostic indicator for SACC. Gene therapy targeting TACSTD2 may be a possible treatment approach for patients with SACC overexpressing this cell-surface marker.