Study of Irinotecan Administered as a Continuous Infusion and Radiation Therapy for Upper Gastrointestinal Cancers

This study is for people with advanced cancer of the digestive tract and cancer that cannot be completely removed by surgery. Radiation therapy is commonly used in the treatment of these types of cancer in combination with a chemotherapy drug, called 5-fluorouracil (5-FU). In this study, doctors will administer the standard dose of radiation therapy in combination with an investigational chemotherapy drug, called irinotecan. Irinotecan can decrease the size of tumors and also appears to increase the effectiveness of radiation. The purpose of this study is to determine the highest dose of irinotecan that can be given safely in combination with radiation therapy, and to determine the side effects when these two treatments are given together. Irinotecan is approved by the Food and Drug Administration (FDA) for the treatment of colon cancer, but is not approved for cancers of the digestive tract. However, the FDA is allowing its use in this research study.