Thymidine Phosphorylase Over-Expression in Oral Squamous Carcinoma Tissue as a Potential Target of Capecitabine

Advanced oral squamous carcinoma (OSC) is typically treated with 5- Fluorouracil (5-FU) based regimens. Capecitabine (CAP) is a thymidine phosphorylase (TP) activated oral fluoropyrimidine, rationally designed to generate 5-FU preferentially within tumours. The high activity of CAP in intestinal and breast cancer suggests that CAP may have a role in the therapy of OSC. This tumour selectively is achieved through exploitation of the significantly higher activity of TP in tumour compared with healthy tissue. In the present study, the epithelial and macrophages TP expression were significantly higher in OSC than in non-dysplastic oral leukoplakia (NDOLP) (p=0.004, p=0.005; respectively). Because OSC is sensitive to 5-FU, and TP expression is significantly higher in OSC than in NDOLP, TP-activated CAP could be a promising therapy worthy of clinical investigation.