Translationally controlled tumor protein as a prognostic marker in metastatic colon cancer.

Abstract

e15513 Background: The translationally controlled tumor protein (TCTP) is a highly conserved protein present in virtually all eukaryotic organisms. TCTP is involved in a variety of normal cell functions and disease processes. Preclinical studies reveal that TCTP has anti-apoptotic properties, promotes cell growth and division, and is involved in cancer progression by promoting invasion and metastasis. Our study explores the potential value of TCTP as a prognostic marker in metastatic colon cancer. Methods: A retrospective analysis of 54 patients with primary metastatic colon cancer was performed. Using immunohistochemistry, TCTP levels in the primary tumor were assessed semiquantitatively via the calculation of cytoplasmic and nuclear H-score. Results: Cytoplasmic TCTP levels in the primary tumor had no statistically significant association with progression-free survival in first-line therapy (PFS1) and overall survival (OS) in our patient population. Patients whose primary tumors had a negative nuclear TCTP expression had significantly better clinical outcomes. The PFS1 for the negative nuclear TCTP expression group was 7.4 months (95% CI, 5.3-9.6) vs 4.5 months (95% CI, 3.4-5.6) in the group with positive nuclear expression (p = 0.023). Patients with a negative nuclear expression of TCTP had a significantly higher median OS (17.1 months; 95% CI, 13.5–20.6) compared to those with positive TCTP nuclear expression (median 11.5 months; 95% CI, 8.5-14.5) (p = 0.031). In Cox regression analyses, a positive nuclear TCTP H-score conferred a higher risk for worse PFS1 (HR 1.960; 95% CI, 1.086-3.537; p = 0.025) and OS (HR 1.882; 95% CI, 1.050-3.371; p = 0.034). The 1-year OS rate in the group with negative nuclear TCTP expression was 80.0% compared to 47.4% in patients with positive nuclear TCTP expression (p = 0.03). Conclusions: The present study suggests that semiquantitative H-score measurement of TCTP levels in the nuclei of tumor cells from the primary tumor is a potential prognostic marker for clinical outcomes in patients with metastatic colon cancer.