Inclusion Criteria:

1. Metastatic or unresectable adenocarcinoma of the upper gastrointestinal tract that
can be measured in at least one dimension according to RECIST criteria by CT or MRI

2. Gastric adenocarcinomas may be included if the primary tumor arises within 5 cm of
the anatomic gastro-esophageal junction (distal esophagus) or from the gastric cardia
as indicated by either endoscope or imaging.

3. Previously untreated with chemotherapeutic agents for unresectable or metastatic
disease.

4. Adjuvant chemotherapy and/or radiotherapy are allowed as long as no oxaliplatin was
used in the past 12 months.

5. ECOG performance status 0 or 1

6. Age > 18 years old.

7. Life expectancy greater than 6 months.

8. Peripheral neuropathy: must be < grade 1

9. Absolute neutrophil count > 1,500/mm3

10. Hemoglobin > 9.0 g/dl

11. Platelet count > 100,000/mm3

12. Hepatic Function:

1. Total Bilirubin < or = to 1.5 x ULN

2. AST and ALT must be < or = to 3.0 x ULN (< or = to 5.0 x ULN if there is liver
metastasis).

13. Creatinine clearance of > 60 ml/min as calculated by the Cockcroft Gault formula.
(Ccr = ((140-Age) X Wt (kg))/ (72 X SCr (mg/100ml) for males).

(Ccr = ((140-Age) X Wt (kg))/ (72 X SCr (mg/100ml) x 0.85 for females)

14. Women of childbearing potential must have a negative pregnancy test by urine or serum
testing.

15. Men and women of childbearing potential must be willing to consent to using effective
contraception while on treatment and for at least 4 months after the last treatment.

16. Patients must have signed IRB approved informed consent

17. Patients must have the ability to comply with study and follow-up procedures.

Exclusion Criteria:

1. Patients with known hypersensitivity to any components of oxaliplatin, leucovorin,
5-fluorouracil (or other fluoropyrimidines) or erlotinib.

2. Women who are breast-feeding or pregnant.

3. Presence of > Grade 2 neuropathy

4. Patients with prior malignancy other than non-melanoma skin cancer or cervical
carcinoma in situ within the past five years

5. Current or prior history of central nervous system or brain metastases

6. Any other medical conditions, which, in the opinion of the investigator, would
preclude subjects to participate in the study.

7. Patients who have received chemotherapy, surgery or radiation therapy within 30 days
prior to the first dose.

8. INR greater than 3.5 for patients on warfarin

9. Known HIV infection