[Neoadjuvant chemotherapy and chemoradiotherapy in the treatment of esophageal cancer]

Adjuvant therapy following surgery has been mainstream in surgical adjuvant therapy for the patients with esophageal cancer in Japan. In western countries, neoadjuvant therapy has become popular in which surgery is performed depending on the effects of preoperative treatment. Neoadjuvant chemotherapy offers the advantage of downstaging the primary tumor and enhancing resectability and the potential advantage of assessing the response to preoperative chemotherapy directly in the primary tumor. Disadvantages include possible emergence of chemotherapy-resistant tumor cells, as well as the delay in achieving effective local tumor control and postoperative morbidity. In the phase II studies, most regimens have included CDDP/5-FU. Pathological CR rates have been less than 10% and median survival terms 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. The majority of trials have employed CDDP/5-FU combined with RT for a total dose of 30 Gy. Pathological CR rates were from 20 to 40% and median survival terms from 12 to 29 months. Neither neoadjuvant chemotherapy nor chemoradiotherapy increased operative morbidity mortality, and there was a statistically significant increase in survival in complete responders. However, though the early and median survival was improved, the cure rate was not. Both therapies remain investigational.