Inclusion Criteria:

- Biopsy-proven adenocarcinoma of the distal esophagus, gastroesophageal junction, or
proximal stomach (within 5cm of gastroesophageal junction)

- No prior treatment for this disease

- AJCC (American Joint Committee on Cancer) clinical stage II to IVA, potentially
resectable disease

- Measurable disease per RECIST 1.0 criteria

- Medically fit for surgery; surgical consultation is encouraged prior to initiation of
treatment

- ECOG (Eastern Cooperative Oncology Group) performance status of 0 or 1

- Male or female; aged equal to or greater than 18 years

- Life expectancy of greater than 3 months

- Good organ, metabolic, bone marrow, and pulmonary function as specified in the
protocol

- Functioning central venous access device prior to treatment initiation

- Women of childbearing potential and men must agree to use adequate contraception
prior to study entry and for at least 6 months following the last administration of
panitumumab

- Ability to understand and the willingness to sign a written IRB (Institutional Review
Board) approved informed consent

Exclusion Criteria:

- Prior treatment for this disease

- History of another primary cancer except curatively treated in situ cervical cancer,
curatively resected nonmelanoma skin cancer, or other primary solid tumor curatively
treated with no active disease present and no treatment administered for at least 5
years prior to enrollment

- History or known presence of central nervous system metastases

- History of allergic reactions attributed to compounds similar chemical or biologic
composition to panitumumab, paclitaxel, carboplatin, or 5FU

- Prior anti-EGFr-antibody therapy or treatment with small molecule EGFr inhibitors

- Systemic chemotherapy, hormonal therapy, immunotherapy, or experimental or approved
proteins/antibodies within 30 days prior to enrollment

- Chronic use of immunosuppressive agents with the exception of corticosteroids

- Any investigational agent or therapy within 30 days prior to enrollment

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situations that would limit compliance with
study requirements

- History of interstitial lung disease, e.g., pneumonitis or pulmonary fibrosis or any
evidence of interstitial lung disease on baseline chest CT scan

- History of any medical or psychiatric condition or laboratory abnormality that in the
opinion of the investigator may increase the risks associated with study
participation or investigational product(s) administration or may interfere with the
interpretation of the results

- Unwilling or unable to comply with study requirements

- Female who tests positive for serum or urine pregnancy test or is breast feeding

- Known positive test(s) for human immunodeficiency virus infection, hepatitis C virus,
acute or chronic active hepatitis B infection

- Major surgery within 28 days or minor surgery within 7 days prior to treatment.
Placement of a central venous access device less than one day prior to treatment
start

- Male or female of childbearing potential (women who are post-menopausal less than 52
weeks, not surgically sterilized, or not abstinent) not consenting to use adequate
contraception prior to study entry and for at least 6 months following the last
administration of panitumumab

- Arterial ischemic event (myocardial infarction, stroke) within 3 months prior to
enrollment

- Ongoing therapeutic anticoagulation