Clinical benefit of chemosensitivity test for patients with regional lymph node-positive esophageal squamous cell carcinoma

Background and Objectives: Patients who have undergone resection for lymph node-positive esophageal squamous cell carcinoma are at high risk of recurrence and early death. The role of the postoperative adjuvant chemotherapy in this population needs to be determined. The present study was designed to determine whether the chemosensitivity test in fresh human esophageal squamous cell carcinoma, using highly purified tumor cells, correlates with the clinical response. Methods: A retrospective review of all patients with resected squamous cell carcinoma of the thoracic esophagus between 1993 and 2000 was performed. We determined the chemosensitivity for cisplatin (CDDP), 5-fluorouracil (5-FU), mitomycin C, and adriamycin in vitro in fresh human esophageal squamous cell carcinoma using the MTT assay. Regional lymph node-positive (NI) patients who received sequential postoperative chemotherapy were compared with lymph node positive patients who underwent surgery alone. Results: A total of 50 patients were reviewed, and chemosensitivity tests were successfully performed in 46 patients: 20 patients received surgery alone (S group), and 26 patients received surgery plus postoperative chemotherapy (SC group) according to results of MTT assay using highly purified tumor cells. When the SC group was divided into an SC-low group (inhibition rate of CDDP + 5-FU was below 85%, n = 15) and an SC-high group (over 85%, n = 11), the SC-high group showed more significant survival prolongation than the S group or the SC-low group (P < 0.01). Conclusions: Our results suggest that the results of the conventional MTT assay may be useful in evaluating the optimum adjuvant chemotherapy for patients with regional lymph node positive (pN1) esophageal squamous cell carcinoma. (C) 2003 Wiley-Liss, Inc.