Inclusion Criteria:

- Patients must be > 18 years of age

- Patients must have a performance status of 0-2 on the Eastern Cooperative Oncology
Group (ECOG) Performance Scale

- Patients must have a predicted life expectancy of at least 12 weeks

- Patients must have a pretreatment granulocyte count of >1500/mm3, a hemoglobin level
of >9.0 gm/dL and the platelet count of >100000/mm3

- Patients must have adequate renal function as documented by a serum creatinine < 2.0
mg/dL

- Patients must have adequate hepatic function as documented by a serum bilirubin < 1.5
mg/dL, regardless of whether patients have liver involvement secondary to tumor.
Aspartate transaminase must be < 3 x institutional upper limit of normal unless the
liver is involved with tumor, in which case the aspartate transaminase must be < 5 x
institutional upper limit of normal

- Patients must have histologically proven adenocarcinoma of the esophagus or gastric
cardia with progression despite prior chemotherapy

- Patients must have disease radiologically measurable bidimensionally

- Patients must have an interval of 4 weeks from prior chemotherapy, immunotherapy, or
radiation therapy

Exclusion Criteria:

- Patients with any active or uncontrolled infection

- Patients with psychiatric disorders that would interfere with consent or follow-up

- Patients with a history of myocardial infarction within the previous six months or
congestive heart failure requiring therapy

- Patients with a history of prior malignancy except for adequately treated basal cell
or squamous cell skin cancer, in situ cervical cancer, or other cancer for which the
patient has been disease-free for at least five years

- Pregnant or lactating women. Men and women of reproductive potential may not
participate unless they have agreed to use an effective contraceptive method

- Presence of clinically apparent central nervous system metastases or carcinomatous
meningitis

- Patients with uncontrolled diabetes mellitus

- Patients with any other severe concurrent disease which, in the judgment of the
investigator, would make the patient inappropriate for entry into this study

- Prior therapy with a deoxyribonucleic acid (DNA) topoisomerase inhibitor

- Patients with known Gilbert's syndrome