Thymidine Phosphorylase/β-tubulin III expressions predict the response in Chinese advanced gastric cancer patients receiving first-line capecitabine plus paclitaxel

Background: To assess the role of Thymidine Phosphorylase and beta-tubulin III in clinical outcome of Chinese advanced gastric cancer patients receiving first-line capecitabine plus paclitaxel. Methods: The clinical data and tumor biopsies prior treatment from 33 advanced gastric cancer patients receiving capecitabine plus paclitaxel (cohort 1, experimental group) and 18 patients receiving capecitabine plus cisplatin (cohort 2, control group) in Beijing Cancer Hospital from July 2003 to December 2008 were retrospectively collected and analyzed for Thymidine Phosphorylase and beta-tubulin III expressions by immunohistochemistry. The relationships between expressions of biomarkers and response or survival were determined by statistical analysis. Results: The median age of 51 patients was 57 years (range, 27-75) with male 34 and female 17, and the response rate, median progression-free survival and overall survival were 43.1%, 120d and 265d. Among cohort 1, the response rate, median progression-free survival and overall survival in beta-tubulin III positive (n = 22) and negative patients (n = 11) were 36.4%/72.7% (positive vs negative, P = 0.049), 86d/237d (P = 0.046) and 201d/388d (P = 0.029), respectively; the response rate (87.5% vs 14.3%, P = 0.01) and median progression-free survival (251d vs 84d, P = 0.003) in Thymidine Phosphorylase positive & beta-tubulin III negative patients (n = 8) were also significantly higher than those in Thymidine Phosphorylase negative & beta-tubulin III positive patients (n = 7). There was no correlation between beta-tubulin III expression and response or survival among cohort 2 (n = 18). Conclusions: In Chinese advanced gastric cancer, Thymidine Phosphorylase positive & beta-tubulin III negative might predict response and prognosis to capecitabine plus paclitaxel chemotherapy. Further prospective evaluation in large samples should be performed to confirm these preliminary findings.