Selumetinib and Erlotinib Hydrochloride in Treating Patients With Locally Advanced or Metastatic Pancreatic Cancer

Inclusion Criteria: * Histologically or cytologically proven adenocarcinoma of the pancreas * Patients must have locally advanced unresectable disease not amenable to curative resection or extrapancreatic metastases; patients must have EITHER radiographically measurable disease (defined as at least one lesion that can be accurately measured in at least one dimension \[longest diameter to be recorded\] as \>= 20 mm with conventional techniques or as \>= 10 mm with spiral computed tomography \[CT\] scan) AND/OR a serum CA19-9 measurement \> 2 x ULN * One prior line of systemic therapy for advanced disease (locally advanced or metastatic) * The following represent acceptable examples meeting the definition of one prior line of therapy: * Gemcitabine as a single agent or in combination with other agents; patients receiving (a) gemcitabine initially alone, with the eventual addition of a second agent; or (b) gemcitabine as part of a combination regimen, followed by gemcitabine alone; are eligible * A non-gemcitabine-based regimen, including (but not limited to) leucovorin calcium, fluorouracil, irinotecan hydrochloride, and oxaliplatin (FOLFIRINOX) or any combination of components therein * Treatment as part of a clinical trial involving cytotoxic agents, small molecule inhibitors, monoclonal antibodies, and/or immunomodulatory agents * For patients with locally advanced disease, prior radiation to the primary tumor is allowable as long as there is clear evidence of disease progression (either radiographic locoregional disease progression and/or a rising CA19-9 level); patients may have received chemotherapy both concurrently and/or sequentially with (either before or after) the radiation and still be eligible for the study, as this would be considered all part of the same course of treatment * Treatment given in the adjuvant setting (radiation and/or chemotherapy, given either concurrently or sequentially) does not count as prior therapy as long as progressive disease occurs \> 6 months following completion of treatment * Life expectancy of greater than 8 weeks * Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Absolute neutrophil count (ANC) \>= 1500/uL * Platelet count \>= 100,000/uL * International normalized ratio (INR) =\< 1.5 (except those subjects who are receiving full-dose warfarin) * Total bilirubin =\< 2.0 mg/dL * Aspartate aminotransferase (AST) or alanine aminotransferase (ALT) =\< 2.5 times the upper limit of normal for subjects * Serum creatinine of =\< 2.0 mg/dL * Pregnancy test for women of childbearing potential (serum or urine beta-human chorionic gonadotropin \[HCG\]) * All patients must be informed of the investigational nature of this study and must sign and give written informed consent in accordance with institutional and federal guidelines * Women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study participation, and for four weeks after dosing with AZD6244 ceases; women of child-bearing potential must have a negative pregnancy test prior to entry; should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately; please note that the AZD6244 manufacturer recommends that adequate contraception for male patients should be used for 16 weeks post-last dose due to sperm life cycle * Ability to understand and the willingness to sign a written informed consent document Exclusion Criteria: * Patients who have had chemotherapy or radiotherapy within 4 weeks (6 weeks for nitrosoureas or mitomycin C) prior to entering the study or those who have not recovered from adverse events due to agents administered more than 4 weeks earlier * Patients may not be receiving any other investigational agents * Patients with known brain metastases should be excluded from this clinical trial * History of allergic reactions attributed to compounds of similar chemical or biologic composition to AZD6244 (or its excipient Captisol) or erlotinib * Previous mitogen-activated protein kinase kinase (MEK) or epidermal growth factor receptor (EGFR) inhibitor use * Patients with corrected QT (QTc) interval \> 480 msecs or other factors that increase the risk of QT prolongation or arrhythmic events (e.g., heart failure, hypokalemia, family history of long QT interval syndrome) including heart failure that (i) meets New York Heart Association (NYHA) class III and IV definitions or (ii) is demonstrated by an left ventricular (LV) ejection fraction \< 55% on baseline echocardiogram, are excluded * Required use of a concomitant medication that can prolong the QT interval * There are potential interactions between erlotinib and cytochrome P450, family 3, subfamily A, polypeptide 4 (CYP3A4) inhibitors and CYP3A4 promoters; although caution and careful monitoring are recommended when use of these compounds is necessary, use of these compounds does not exclude patients from participating in this trial * Refractory nausea and vomiting, chronic gastrointestinal diseases (e.g. inflammatory bowel disease), or significant bowel resection that would preclude adequate absorption * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection or psychiatric illness/social situations that would limit compliance with study requirements * Pregnant women are excluded from this study; therefore, a negative pregnancy test is required for women of childbearing potential; breastfeeding should be discontinued if the mother is treated with AZD6244 * Human immunodeficiency virus (HIV)-positive patients on combination antiretroviral therapy are ineligible