Expression and clinical significance of SPARC in clinical stage II tongue squamous cell carcinoma.

BACKGROUND AND OBJECTIVE Secreted protein acidic and rich in cysteine (SPARC) is expressed widely in malignant tumors. It is related to prognosis and biological behaviors of tumors. This study was to detect the expression of SPARC in stage II tongue squamous cell carcinoma and analyze its relationship with prognosis. METHODS Tongue carcinoma samples (T2N0M0) were obtained from 55 patients treated in Sun Yat-sen University Cancer Center from January 1999 to December 2003. Twenty-five squamous epithelium samples with tongue inflammation nearby were taken as control. Immunohistochemistry was used to detect the expression of SPARC. Its relationships with survival, occult lymph node metastasis and recurrence were analyzed. RESULTS The positive rate of SPARC was 49.1% in tongue cancer tissues and 0 in normal tissues (p < 0.001). The accumulative 5-year survival rate was significantly lower in SPARC-positive patients than in SPARC-negative patients (30.0% vs. 85.3%, p = 0.005). The positive rate of SPARC was significantly higher in tissues with occult lymph node metastasis than in those without metastasis (86.7% vs. 35.0%, p = 0.001), and higher in tissues with recurrence than in those without recurrence (100% vs. 31.5%, p < 0.001). The expression of SPARC was positively correlated to occult lymph node metastasis (r = 0.46, p < 0.001) and recurrence (r < 0.595, p < 0.001). CONCLUSION SPARC is highly expressed in stage II tongue squamous cell carcinoma, and positively correlated to survival, occult lymph node metastasis and recurrence.