Gemcitabine and Radiation Therapy in Treating Patients With Cancer of the Pancreas

DISEASE CHARACTERISTICS:

* Histologically confirmed invasive adenocarcinoma of the pancreas

  * Prior gross total resection via a pancreaticoduodenectomy (Whipple resection or total pancreatectomy) within the past 2 months
* No clinical evidence of gross residual disease at time of surgery

  * No focally positive margins (tumor at the margin)
* No unresected nodal disease or metastatic disease to the liver, peritoneal surfaces, or elsewhere

PATIENT CHARACTERISTICS:

Age:

* Over 18

Performance status:

* ECOG 0-2

Life expectancy:

* More than 6 months

Hematopoietic:

* Granulocyte count greater than 1,500/mm3
* Hemoglobin greater than 10 g/dL
* Platelet count greater than 100,000/mm3

Hepatic:

* Bilirubin less than 2.0 mg/dL

Renal:

* Creatinine less than 2.0 mg/dL

Other:

* Able to maintain adequate oral nutrition
* Documented stable weight (no more than 5 lbs weight loss) for at least 2 weeks prior to study
* No other malignancy within the past 2 years except inactive nonmelanoma skin cancer or carcinoma in situ of the cervix or breast
* Non-metastatic prostate cancer allowed if more than 2 year survival likely
* No other serious medical or psychiatric illness that would preclude study or limit survival to less than 2 years
* Not pregnant
* Negative pregnancy test
* Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* No concurrent routine growth factors

Chemotherapy:

* No prior chemotherapy for pancreatic cancer

Endocrine therapy:

* Not specified

Radiotherapy:

* No prior abdominal radiotherapy for pancreatic cancer

Surgery:

* See Disease Characteristics