Comparison of Chemotherapy Before and After Surgery Versus After Surgery Alone for the Treatment of Gallbladder Cancer

Inclusion Criteria: * Patient must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0-1 * Patient must have histologically-confirmed T2 or T3 gallbladder cancer discovered incidentally at the time of or following routine cholecystectomy for presumed benign disease * NOTE: Patients with histologically-confirmed Tis, T1a, T1b, or T4 tumors are not eligible * Patient must have undergone initial cholecystectomy within 12 weeks prior to randomization * Patient must have the ability to understand and the willingness to sign a written informed consent document * Leukocytes \>= 3,000/mcL (obtained =\< 28 days prior to randomization) * Absolute neutrophil count \>= 1,500/mcL (obtained =\< 28 days prior to randomization) * Platelets \>= 100,000/mcL (obtained =\< 28 days prior to randomization) * Total bilirubin =\< institutional upper limit of normal (ULN) except in patients with Gilbert's syndrome. Patients with Gilbert's syndrome are eligible if direct bilirubin \< 1.5 x ULN of the direct bilirubin (obtained =\< 28 days prior to randomization) * Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase \[SGOT\]) and alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase \[SGPT\]) =\< 2.5 x institutional ULN (obtained =\< 28 days prior to randomization) * Serum creatinine =\< institutional ULN OR creatinine clearance \>= 50 mL/min/1.73 m\^2 (Based on Cockcroft Gault estimation) (obtained =\< 28 days prior to randomization) * Hu…