Aprepitant in Preventing Nausea and Vomiting in Patients Undergoing Chemotherapy and Radiation Therapy for Pancreatic Cancer

Inclusion Criteria: * Histologic or cytologic diagnosis of carcinoma arising from the pancreas * Resected or unresectable pancreatic cancer, potentially resectable, or resectable (neoadjuvant) disease (stage II and III); stage IV patients with symptomatic back pain requiring palliation are also eligible at the discretion of the Principal Investigator (PI); resected patients, i.e. - "Whipple" of biliary ductal cancers are also eligible at the discretion of the PI * Performance status 0 or 1 on the Eastern Cooperative Oncology Group (ECOG) scale * Evidence of disease; this can be measurable, evaluable, or nonmeasurable * Estimated life expectancy of at least 12 weeks * Absolute neutrophil (segmented and bands) count (ANC) \>= 1.5 X 10\^9/L * Platelets \>= 100 X 10\^9/L * Hemoglobin \>= 9 g/dL * Bilirubin =\< 1.5 times upper limit of normal (ULN) * Alkaline phosphatase (AP) =\< 3.0 ULN ( AP =\< 5 x ULN is acceptable if liver has tumor involvement) * Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) =\< 3.0 ULN (AST and ALT =\< 5 x ULN is acceptable if liver has tumor involvement) * Albumin \>= 3.0 g/dL * Signed informed consent from patient * Male and female patients with reproductive potential must use an approved contraceptive method (e.g., intrauterine device, birth control pills, or barrier device) during and for 3 months after the study Exclusion Criteria: * Active infection (at the discretion of the investigator) * Neuroendocrine tumor of the pancreas * Documented brain metastasis; brain imaging in symptomatic patients is required to rule out metastases, but not required in asymptomatic patients * Pregnancy * Breast feeding * Serious concomitant systemic disorders incompatible with the study (at the discretion of the investigator) * Use of any investigational agent within 4 weeks before enrollment into the study * Significant cardiovascular disease in the form of abnormal electrocardiogram (ECG) coupled with clinical features of recent or recurrent cardiac disease (including myocardial infarction, angina or hypertension) * Prior treatment with chemotherapy for pancreatic cancer * Clinically significant effusions (pleural or peritoneal) that cannot be drained