Gemcitabine With or Without Capecitabine and/or Radiation Therapy or Gemcitabine With or Without Erlotinib in Treating Patients With Locally Advanced Pancreatic Cancer That Cannot Be Removed by Surgery

DISEASE CHARACTERISTICS:

* Histologically confirmed adenocarcinoma of the pancreas meeting the following criteria:

  * De novo locally advanced disease
  * Unresectable disease
  * Stage III according to the UICC classification

    * No distant metastases
    * No localized stage IA-IIB or metastatic stage IV disease according to UICC classification
  * Not considered for curative resection after pluridisciplinary discussion

PATIENT CHARACTERISTICS:

Inclusion criteria:

* ECOG performance status 0-2
* Life expectancy ≥ 12 weeks
* Polynuclear neutrophils ≥ 1.5 x 10\^9/L
* Platelets ≥ 100 x 10\^9/L
* Hemoglobin ≥ 9 g/dL
* Total bilirubin ≤ 1.5 times upper limit of normal (ULN)

  * For patients who have had a recent biliary drain and whose bilirubin is descending, a value of ≤ 3 times ULN is acceptable
* Creatinine ≤ 2 mg/dL
* AST and ALT ≤ 2.5 times ULN
* Alkaline phosphatase ≤ 5 times ULN
* Albumin ≥ 25 g/L
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception during and for 3 months after completion of therapy

Exclusion criteria:

* Diarrhea ≥ grade 2 and/or uncontrolled diarrhea
* Affiliated with a social security regime
* Unable to follow instructions for psychological, familial, or geographical reasons
* Allergic to one of the ingredients in erlotinib hydrochloride
* Cancer within the past 5 years, except for in situ cancer of the neck of the uterus or basal cell skin cancer
* Severe infection
* Ophthalmic disease (i.e., inflammation, keratopathy, or infection)
* Symptomatic coronary or cardiac insufficiency, myocardial infarction, or stroke within the last 6 months
* Unable to take oral treatments
* Gastrointestinal disorders that could be associated with absorption disorders
* Untreated gastric or duodenal ulcer

PRIOR CONCURRENT THERAPY:

* No prior radiotherapy (including abdominal radiotherapy) or chemotherapy for any reason
* No prior anti-epidermal growth factor-receptor therapy