[Chemotherapy and multimodality therapy in the treatment of esophageal cancer]

Many single-agent phase II studies for patients with esophageal cancer had been performed, and at least five agents with modest activity have been indentified, BLM, MMC, CDDP, VDS and MTX, that revealed no CR. Even in the phase II study of 254-S, a new anticancer platinum complex, with a response rate of 43%, CR could not be recognized. Only two regimens of combination chemotherapy have been studied extensively, CDDP/BLM/VDS and CDDP/5-FU. The combination of CDDP/5-FU has gained popularity and JEOG phase II study revealed a response rate of 36%. As surgical adjuvant therapy, postoperative adjuvant therapy has been common in Japan. The 4th JEOG phase III clinical trial, comparing surgery alone and postoperative chemotherapy of CDDP/VDS, showed no additive effect to surgery by postoperative chemotherapy with such a regimen. In western countries, neoadjuvant chemotherapy is frequent and most of the regimens include CDDP/5-FU. Pathological CR rates were less than 10%, and median survival terms were from eight to 28 months. The rationale for the concurrent use of chemotherapy and radiotherapy is to combine an agent that has an effect upon systemic micrometastases with a modality that enhances local tumor control. In addition, a number of chemotherapeutic agents have radiosensitizing effects. In western countries, more than 35 trials studying over 1400 patients have been reported. The majority of trials have employed CDDP/5-FU combined with RT to a total dose of 30Gy. Pathological CR rates were from 20 to 40% and median survival terms were from 12 to 29 months. Both neoadjuvant chemotherapy and chemoradiotherapy did not change operative morbidity or mortality, and there was a statistically significant increase in survival in complete responders. However, early and median survival seems improved but cure rates are not. Both therapies require further investigation.