[Thymidylate synthase expression in patients with hypopharyngeal carcinoma].

We analyzed the relationship between clinical response to neo-adjuvant chemotherapy including 5-fluorouracil (5-FU) in patients with hypopharyngeal carcinoma (HPC) and thymidylate synthase (TS) expression in their tumors. TS expression was evaluated with immunohistochemical staining techniques on biopsy specimens from HPC patients. TS immunostaining was divided into four levels (TS0-TS3) according to its level and pattern. The relationship between prognosis, tumor size, nodal status, differentiation of tumor cells and TS expression were also investigated. There was a statistically significant association between the level of TS expression and tumor size (p < 0.01). In terms of the effectiveness of chemotherapy, tumor differentiation, nodal status and prognosis, a statistical difference was not found in TS expression. These results suggest that the level of TS expression may show the degree of tumor proliferation, but may not necessarily be useful to obtain a response to chemotherapy including other drugs, e.g., cisplatin and other derivatives of platinum.