Individualized Dose Escalation of 5-FU for Gastrointestinal Cancer

Inclusion criteria

• Age ≥ 18 years
• Diagnosis of metastatic or locally advanced/inoperable colorectal cancer or non-colorectal gastrointestinal cancer (including cancers of the stomach, esophagus, appendix, small bowel, and ampulla)
• Clinically appropriate staging imaging of the chest, abdomen, and pelvis performed within 30 days prior to registration
• ECOG Performance Status: 0-1

Exclusion criteria

• Any prior receipt of oxaliplatin or fluoropyrimidine chemotherapy (other than radiation-sensitizing fluoropyrimidine chemotherapy)
• Prior receipt of systemic chemotherapy in the 6 months prior to Day 1 of Cycle 1 of FOX (other than radiation-sensitizing chemotherapy)
• Known mismatch repair deficiency or microsatellite instability-high disease
• Known dihydropyrimidine dehydrogenase (DPD) deficiency, as identified by clinically indicated screening
• Any confirmed second malignancy that is likely to require systemic therapy during the course of the six-month study period, in the opinion of the enrolling investigator
• Any of the following baseline laboratory abnormalities:

• Absolute neutrophil count (ANC) < 2,500/mm3
• Platelet count < 100,000/mm3
• Hemoglobin < 9 g/dL
• Creatinine > 1.5 x ULN
• Total bilirubin > 1.5 x ULN
• AST/ALT > 5 x ULN
• Patients who are unable to provide informed consent
• Patients who are pregnant or breastfeeding
• Patients who are incarcerated, homeless, or have active substance use disorders