Flow cytometric DNA analysis does not predict the radiochemoresponsiveness of esophageal cancer

The relationship between the DNA pattern and the responsiveness to chemotherapy or chemoradiotherapy has been evaluated in 30 patients with squamous cell carcinoma of the esophagus. In 24 patients polychemotherapy with cisplatin (100 mg/m² on day 1) and 5-fluorouracil (1,000 mg/m²/24 h, continuous infusion of 120 h) every 3 weeks, was performed. Six other patients received chemoradiotherapy with cisplatin 80 mg/m² on day 1 and 18.5 Gy (split course). Before treatment, at least three endoscopic biopsies were taken from each tumor and frozen at -85°C. Five patients were excluded from the evaluation, three because of interrupted treatment and two due to unsuitable biopsy material obtained endoscopically. The response rate to the cytoreductive treatment was 40% (10/25). DNA content was analyzed with flow cytometry. Out of 25 evaluable patients, a diploid and aneuploid tumor was present in 8 (32.0%) and 17 (68.0%) patients, respectively. According to the DNA pattern, a major response was observed in 4 of 8 patients with a diploid tumor and in 6 of 17 patients with an aneuploid tumor (P = 0.5). No relationship between the percentage of cells in the S-phase and the response to the cytoreductive treatment was evident. Although a slightly higher percentage of major responses was found in euploid tumors, there is no evidence that flow-cytometric DNA analysis can be helpful in the selection of patients for chemotherapy or chemoradiotherapy.