Combination Chemotherapy, and Radiation Therapy in Treating Patients With Locally Advanced Pancreatic Cancer

• Antitumor and clinical benefit response [ Time Frame: After 6 weeks of chemotherapy and then after 4 weeks of chemo-radiation. ]
  
• Toxicity [ Time Frame: Weekly ]
  
• Correlation of achieved steady-state plasma levels with clinical toxicity [ Time Frame: during protracted venous infusion ]
  Correlative
  
  
• Importance of polymorphic variations in genomic DNA of pertinent genes on response and toxicity [ Time Frame: Prior to starting therapy ]
  Correlative
  
  
• Gene expression profiles of primary and metastatic pancreatic tumors before and after treatment [ Time Frame: Before and after treatment ]
  Correlative
  
  

Drug: fluorouracil
2700 mg/m5 IV over 24 hr after gemcitabine weeks 1 & 2; Repeat one 3-week cycle starting day 22
Drug: gemcitabine hydrochloride
750 (females) or 900 (males) mg/m5 IV over 30 min (day 2)weeks 1 & 2; Repeat one 3-week cycle starting day 22
Drug: leucovorin calcium
20 mg/m5 PO (day 1) and 20 mg/m5 IV (day 2) weeks 1 and 2; Repeat one 3-week cycle starting day 22
Drug: oxaliplatin
48 mg/m5 IV over 2 hr weeks 1, 2, 4, and 5
Procedure: adjuvant therapy

Patients who have undergone surgical resection, after post-operative recovery, will receive two additional cycles of gemcitabine/5-FU/leucovorin. Patients will then be followed at 3 month intervals with a history and physical exam, CT scan of the chest/abdomen/pelvis, and tumor markers.

If surgical resection is not possible, patients with stable or responsive disease will resume gemcitabine/5-FU/leucovorin and continue on it indefinitely until disease progression provided the patient tolerates it and wishes to remain on therapy.

Procedure: conventional surgery
Restaging with repeat imaging studies will be performed four weeks after completion of the chemo-radiation. If no contraindication for surgical resection is identified, resection will be performed six to eight weeks after completing chemoradiation. At the time of surgical resection, an extensive examination of the abdomen will be performed to exclude the presence of metastatic disease. All operations will be performed with curative intent with resection of all gross tumor (ie R0 [negative margins] or R1 [positive microscopic margins]). Resection of adjacent involved organs or vascular structures will be performed as clinically indicated.
Procedure: neoadjuvant therapy
Eligible patients will receive an initial two cycles of chemotherapy with gemcitabine 750 (females) or 900 (males) mg/m5 over 30 minutes followed by a 24-hour infusion of fluorouracil 2700 mg/m5 on days 2 and 9 of a 21-day cycle . Calcium leucovorin 20 mg/m5 will be given orally on days 1 and 8 and by IV push on days 2 and 9 prior to the 5-FU. A window of -2 up to +7 days will be allowed to start planned cycles of therapy provided all other criteria to restart the new cycle has been met. Patients will require a central venous catheter (Port, Hickman or Groshong catheter) for the administration of 5-FU.
Radiation: radiation therapy
A re-staging CT scan, which will be obtained as part of the radiation simulation, will be used to assess any possible response to the initial two cycles of chemotherapy. Unless the patient has developed evidence of metastatic disease, chemoradiation will proceed. Patients who required no treatment delays will commence chemoradiation on day 42. If a one-week delay is needed before cycle 2 of neo-adjuvant chemotherapy can be delivered, the patient will begin chemoradiation on day 49 provided treatment-related toxicity has resolved. If cycle 2 could not be given (2 or more week delay for resolution of treatment-related toxicity), then chemoradiation will begin once toxicity has resolved (may be earlier than day 42).

OBJECTIVES:

• Determine the antitumor and clinical benefit response to neoadjuvant chemoradiotherapy comprising gemcitabine, fluorouracil, leucovorin calcium, and oxaliplatin in patients with potentially resectable locally advanced adenocarcinoma of the pancreas.
• Determine the toxic effects of this regimen in these patients.
• Determine the achieved steady-state plasma levels of gemcitabine and fluorouracil in these patients and correlate these plasma levels with clinical toxicity associated with this regimen.
• Determine the potential importance of polymorphic variations in genomic DNA of pertinent genes (whose protein products are targets of the antineoplastic drugs used in this study) on response to and toxicity of this regimen in these patients.
• Determine the gene expression profiles of primary and metastatic pancreatic tumors before and after treatment with this regimen.

OUTLINE:

• Neoadjuvant chemotherapy: Patients receive gemcitabine IV over 30 minutes and fluorouracil IV continuously over 24 hours on days 2 and 9, and leucovorin calcium orally on days 1 and 8 and IV on days 2 and 9. Treatment repeats every 21 days for 2 courses in the absence of disease progression or unacceptable toxicity.
• Neoadjuvant chemoradiotherapy: Beginning on day 42, patients undergo chemoradiotherapy comprising oxaliplatin IV over 2 hours on days 42, 49, 56, 63, 70, and 77 and fluorouracil IV continuously on days 42-78 with external beam radiotherapy.
• Surgery: Patients undergo surgical resection 42-56 days after completion of chemoradiotherapy.
• Adjuvant chemotherapy: After post-operative recovery, patients receive 2 additional courses of gemcitabine, fluorouracil, and leucovorin calcium. If surgical resection is not possible, patients with stable or responsive disease resume gemcitabine, fluorouracil, and leucovorin calcium indefinitely in the absence of disease progression or unacceptable toxicity.

Patients are followed every 3 months.

PROJECTED ACCRUAL: A total of 50 patients will be accrued for this study.