A Phase II Study to Assess the Efficacy and Safety of Preoperative Chemo With Radiation Therapy for Patients With Borderline Unresectable Adenocarcinoma of the Pancreas

Inclusion Criteria:

1. Ages 18 years and above. There will be no upper age restriction.
2. Eastern Cooperative Oncology Group (ECOG) performance status ≤ 2. (See Appendix A -ECOG Performance Status Scale).
3. Cytologic or histologic proof of adenocarcinoma of pancreas.
4. Adequate renal, and bone marrow function:

   1. Leukocytes \>= 3,000/uL (upper limit)
   2. Absolute neutrophil count \>= 1,500/uL (upper limit)
   3. Platelets \>= 100,000/Ul
   4. Serum creatinine \<= 2.0 mg/dL
5. Hepatic function (endoscopic or percutaneous drainage as needed)

   a. Aspartate aminotransferase (AST)-(SGOT)/Alanine aminotransferase (ALT) (SGPT) \<= 5 X institutional ULN (upper limit of normal)
6. Borderline resectable pancreatic cancer:

   1. Short segment hepatic artery abutment (\< 180° involvement)
   2. Tumor abutment (\<180° ) of superior mesenteric artery
   3. Superior mesenteric/portal vein involvement beyond that of a simple resection and reconstruction
   4. Pancreatitis that obscures the determination of vessel involvement and may preclude an otherwise curative operation
7. Unresectable pancreatic cancer:

   1. Tumors that encase (\> 180° involvement) single or multiple arteries and veins (celiac axis, superior mesenteric artery, superior mesenteric/portal vein, hepatic artery)
   2. Occlusion of superior mesenteric/portal vein

Exclusion Criteria:

1. Infections such as cholangitis, pneumonia, or wound infections that would preclude protocol therapy.
2. Women with a positive urine or serum pregnancy test are excluded from this study; women of childbearing potential (defined as those who have not undergone a hysterectomy or who have not been postmenopausal for at least 24 consecutive months) must agree to refrain from breast feeding and practice adequate contraception as specified in the informed consent. Adequate contraception consists of oral contraceptive, implantable contraceptives, injectable contraceptives, a double barrier method, or abstinence.
3. Subjects cannot have known heptic or peritoneal metastases detected by ultrasound (US), CT scan, or laparotomy/laparoscopy prior to treatment.
4. Subjects with unstable angina or New York Heart Association (NYHA) Grade II or greater congestive heart failure will be excluded (see Appendix B).
5. Known presence of central nervous system or brain metastases
6. Subjects with prior radiotherapy to the upper abdomen or liver will be excluded.
7. Subjects will be excluded if deemed unable to comply with study and/or follow-up procedures.
8. Subjects with a known hypersensitivity to Gemzar are excluded.
9. Multiple positive lymph nodes, which will make the radiotherapy treatment volume too large. Peripancreatic involved nodes can be included in the radiotherapy treatment volume if the field of involved nodes is less than 7.5cm.