Dasatinib and Gemcitabine Hydrochloride or Gemcitabine Hydrochloride Alone in Treating Patients With Pancreatic Cancer Previously Treated With Surgery

Inclusion Criteria: * Written informed consent before beginning any protocol specified procedures * Histologically proven pancreatic adenocarcinoma * Any T, any N, M0 disease that has had all gross disease resected (R0 or R1 resection) * ECOG Performance status index 0 or 1 * Absolute Neutrophils \>= 1.5 x 10\^9/L * Platelets \>= 100 x 10\^9/L * Hemoglobin \>= 10 g/dL * Total bilirubin =\< 2.0 x UNL; subjects with Gilbert's syndrome, confirmed by genotyping or invader UGTIA1 molecular assay before study entry must have total bilirubin \< 3 x UNL * ASAT (SGOT) and ALAT (SGPT) =\< 2.5 x UNL * Alkaline Phosphatase =\< 5 x UNL * Creatinine \< 1.5 x UNL * Serum Na, K+, Magnesium, Phosphate and Calcium \>= LNL * First study treatment must be given within 60 days after surgery and within 7 days after randomization * Patients must be accessible for treatment and follow-up and compliant with study procedures * Negative pregnancy test (urine or serum) within 7 days before first study treatment for all women of childbearing potential, whom also must implement adequate non-hormonal contraceptive measures during study treatment and for at least 3 months after the last dose of study therapy * Ability to take oral medication (dasatinib must be swallowed whole) Exclusion Criteria: * Prior or concurrent systemic anticancer therapy (immunotherapy, hormonal therapy, biological therapy, or chemotherapy) for pancreatic cancer * Prior or concurrent radiation therapy for pancreatic cancer * Pregnant or lactating patients * M1 pancreatic cancer * Concurrent congestive heart failure, unstable angina pectoris, or M1 within the 6 months before first study treatment * Uncontrolled hypertension or high-risk uncontrolled arrhythmias * Any history of clinically significant ventricular arrhythmias (such as ventricular tachycardia, ventricular fibrillation, or torsades de pointes) * Diagnosed or suspected congenital long QT syndrome * Prolonged QTc interval on pre-entry electrocardiogram (\> 450 msec) * History of significant neurologic or psychiatric disorders including psychotic disorders, dementia or seizures that would prohibit the understanding and giving of informed consent * Past or current history of neoplasm other than pancreatic adenocarcinoma, except for: curatively treated non-melanoma skin cancer; in situ carcinoma of the cervix; other cancer curatively treated and with no evidences of disease for at least 1 year * Concurrent treatment with other experimental drugs or treatment with investigational drugs within 30 days of first study treatment * Currently receiving drugs with known significant CYP 3A4 inhibitory effects (such as ketoconazole, itraconazole, troleandomycin, erythromycin, diltiazem, verapamil, ritonavir, indinavir) * Concurrent administration with inducers of CYP 3A4 may result in a lower exposure to dasatinib and are therefore not allowed (e.g., phenytoin, carbamazepine, rifampicin, phenobarbital, pentobarbital, or St John's Wort) * Known allergy reactions to dasatinib or gemcitabine or excipients used in the study * History of significant bleeding disorders unrelated to cancer, including: diagnosed congenital bleeding disorders (e.g., Von Willebrand's disease); diagnosed acquired bleeding disorder within 1 year (e.g., acquired anti-factor VIII antibodies); ongoing or recent (=\< 3 months) significant gastrointestinal bleeding * Patients currently taking drugs that are generally accepted to have a risk of causing Torsades De Pointes including: quinidine, procainamide, disopyramide; amiodarone, sotalol, ibutilide, dofetilide; erythromycins, clarithromycin; chlorpromazine, haloperidol, mesoridazine, thioridazine, pimozide; cisapride, bepridil, droperidol, methadone, arsenic, chloroquine, domperidone, halofantrine, levomethadyl, pentamidine, sparfloxacin, lidoflazine * Concurrent treatment with intravenous bisphosphonates; prior treatment should be stopped at least 2 weeks before first dose of study treatment * Concurrent medical condition which may increase the risk of toxicity, including pleural or pericardial effusion or any grade * Active uncontrolled infection requiring parenteral antimicrobials