Testing the Use of Chemotherapy After Surgery for High-Risk Pancreatic Neuroendocrine Tumors

Inclusion Criteria

• •Participants must have a histologic diagnosis of well-differentiated pancreatic neuroendocrine tumor (pNET) that was resected between 14 and 120 days prior to registration. Participants must have a scan within 90 days prior to registration without evidence of metastatic disease. Acceptable scans are multiphase computed tomography (CT) abdomen, magnetic resonance imaging (MRI) with intravenous (IV) contrast of the abdomen, or positron emission tomography (PET)-CT DOTATATE imaging if the DOTATATE PET-CT included IV iodine contrast for the CT portion of the exam
• •Resection must have been an R0 or R1 per treating investigator's assessment and/or pathology report
• •Ki-67 testing, which is considered part of standard of care in the pathology report, must have been performed between 14 and 90 days prior to registration and the result must be \>= 3% and =\< 55%. Treating investigators are encouraged to contact the S2104 Study Chairs and/or the study pathology chair with questions. If more than one Ki-67 is reported (e.g., primary tumor versus lymph node or metastatic site), the highest one should be considered for the study eligibility criteria
• •Participants with localized resected pNETS must have a Zaidi score of \>= 3 derived by the following factors and points:
• •* 1 point; symptomatic tumor defined as one of the following:
• •* Gastrointestinal bleed
• •* Jaundice
• •* Gastrointestinal obstruction
• •* Pain from primary tumor prior to surgical resection
• •* Pancreatitis
• •* 2 points; primary pancreas tumor size \> 2 cm
• •* 1 point; Ki-67 3% to 20%
• •* 1 point; lymph node positivity = 1
• •* 6 points; Ki-67 21% to 55%
• •Participants may have received resection/ablation of liver oligo-metastatic disease (up to 5 liver metastases) at the time of well-differentiated pNET resection
• •Participants must have recovered from effects of surgery as determined by the treating investigator
• •Participants must be \>= 18 years old
• •Participants must have Zubrod performance status of 0-2
• •Participants must have a complete medical history and physical exam within 28 days prior to registration
• •Leukocytes \>= 3 x 10\^3/uL (within 28 days prior to registration)
• •Absolute neutrophil count \>= 1.5 x 10\^3/uL (within 28 days prior to registration)
• •Platelets \>= 100 x 10\^3/uL (within 28 days prior to registration)
• •Total bilirubin =\< institutional upper limit of normal (ULN) unless history of Gilbert's disease. Participants with history of Gilbert's disease must have total bilirubin =\< 5 x institutional ULN (within 28 days prior to registration)
• •Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) =\< 3 x institutional ULN (within 28 days prior to registration)
• •Serum creatinine =\< 1.5 x institutional ULN (within 28 days prior to registration)
• •Calculated creatinine clearance \>= 50 ml/min (within 28 days prior to registration)
• •Participants must be able to swallow pills
• •Participants must be able to tolerate CT or magnetic resonance (MR) imaging including contrast agents as required for their treatment and the protocol
• •No other active malignancy or history of prior malignancy is allowed, except for the following: adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, adequately treated stage I or II cancer from which the participant is currently in complete remission, or any other cancer from which the participant has been disease free for two years
• •Participants must be informed of the investigational nature of this study and must sign and give informed consent in accordance with institutional and federal guidelines