Gemcitabine With or Without Sorafenib in Treating Patients With Locally Advanced or Metastatic Pancreatic Cancer

DISEASE CHARACTERISTICS: Inclusion criteria: * Diagnosis of adenocarcinoma of the pancreas * Locally advanced or metastatic disease * Measurable disease, defined as at least 1 lesion measurable by RECIST criteria Exclusion criteria: * Brain metastases PATIENT CHARACTERISTICS: Inclusion criteria: * WHO performance status 0-2 * Absolute neutrophil count \> 1,500/mm\^3 * Platelet count \> 100,000/mm\^3 * Creatinine \< 1.5 times normal * Transaminases \< 2 times normal (5 times normal if liver metastases) * Total bilirubin \< 1.5 times normal * Fertile patients must use effective contraception Exclusion criteria: * Pregnant or nursing * Intestinal occlusion * Prior inflammatory intestinal disease * Crohn's disease * Hemorrhagic rectal colitis * Peripheral neuropathy \> grade 2 * Other severe illness, including any of the following: * Unstable cardiac disease, even if treated * Psychological or neurological disease including dementia * Uncontrolled active infection * Other severe illness that would compromise study participation * Impossible to receive study therapy due to geographical, social, or psychological reasons * Other malignancy within the past 5 years except basal cell skin cancer or carcinoma in situ of the cervix PRIOR CONCURRENT THERAPY: Inclusion criteria: * See Disease Characteristics * At least 6 months since prior chemotherapy or radiochemotherapy * At least 4 weeks since prior radiotherapy and/or surgery Exclusion criteria: * Prior therapy for advanced disease * Prior inhibitors of kinase signaling (e.g., ras/raf, MEK, AKT, mTOR, or farnesyl transferase) * Prior inhibitors of angiogenesis (e.g., bevacizumab) * Prior organ graft or allogeneic transplantation * Prior extensive intestinal resection * Concurrent participation in another therapeutic study * Concurrent inductors of CYP3A4 (e.g., barbiturates, anti-epileptics, or rifampicin)