ChemoRT With Adjuvant Chemo in Pancreatic Cancer (TARCEVA)

Inclusion criteria 1. Resection of a stage I/II pancreatic adenocarcinoma of the pancreas (R0/R1) and a candidate to receive postoperative adjuvant chemoradiation. R2 (laparoscopic resection) based on the surgeons operative note will be excluded from the study. 2. Aged 18 years or older. 3. ECOG performance status \< 1. 4. The effects of Erlotinib and Capecitabine on the developing human fetus at the recommended therapeutic dose are unknown. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control) prior to study entry and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. 5. Patients must have normal organ and marrow function. 6. Provision of written informed consent 7. Patients must have a working knowledge of English in order to complete the quality of life questionnaires. Patients that do not meet this requirement will be exempt from the QoL assessment, but remain eligible for all other components of the study. Exclusion criteria 1. Known severe hypersensitivity to Erlotinib any of the excipient of this product. Hypersensitivity to Capecitabine, doxifluridine, or 5-FU. 2. Other coexisting malignancies or malignancies diagnosed within the last 5 years, with the exception of basal cell carcinoma, non-invasive early stage bladder cancer (\<T1), and cervical cancer in situ. 3. 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. 4. Concomitant use of phenytoin, carbamazepine, barbiturates, rifampicin, phenobarbital, or St John's Wort. Careful monitoring of PT/INR must be done for patients taking Warfarin. 5. Incomplete healing from previous oncologic or other major surgery. 6. Gastrointestinal tract disease resulting in an inability to take oral medication. 7. Pregnant women are excluded from this study because Erlotinib is an epidermal growth factor inhibitor with the potential for teratogenic or abortifacient effects based on the data suggesting that EGFR expression is important for normal organ development. Because there is an unknown but potential risk for adverse events in nursing infants secondary to treatment of the mother with Erlotinib, breastfeeding should be discontinued if the mother is treated with Erlotinib. Capecitabine is also potentially teratogenic and its metabolites can be found in breast milk. 8. Patients with known AIDS or who are HIV-positive on anti-retroviral therapy are excluded since patients' immune deficiency are at increased risk of lethal infection when treated with marrow-suppressive therapy, and interactions between Erlotinib and anti-retroviral therapy are unknown. If patients have known risk factors of HIV they should be tested based on the discretion of the treating oncologist. 9. Any evidence of clinically active interstitial lung disease (patients with chronic stable radiographic changes who are asymptomatic need not be excluded). 10. Previous radiation to the abdomen. 11. Previous chemotherapy for pancreatic cancer.