Saracatinib in Treating Patients With Locally Advanced or Metastatic Stomach or Gastroesophageal Junction Cancer

Inclusion Criteria: * Histologically or cytologically confirmed adenocarcinoma of the stomach or gastroesophageal junction (GEJ) * Tumors of the GEJ must be sub-specified as type I, II, or III using the Siewert classification * Metastatic or locally advanced disease * Patients with local/regional disease only, must have unresectable disease * Measurable disease, defined as ≥ 1 lesion that can be accurately measured in ≥ 1 dimension (longest diameter to be recorded) as ≥ 20 mm by conventional techniques or as ≥ 10 mm by spiral computed tomography (CT) scan * No known brain metastases * Eastern Cooperative Oncology Group (ECOG) performance status (PS) 0-2 OR Karnofsky PS 60-100% * Life expectancy \> 3 months * Platelet count ≥ 100,000/mm³ * Leukocytes ≥ 3,000/mm³ * Absolute neutrophil count ≥ 1,500/mm³ * Hemoglobin \> 9 g/dL * Total bilirubin normal * Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ≤ 2.5 times upper limit of normal * Creatinine normal OR creatinine clearance ≥ 60 mL/min * Urine protein creatinine ratio \< 1.0 OR urine protein \< 1,000 mg by 24-hour urine collection Exclusion Criteria: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No condition that potentially impairs the ability to swallow or absorb AZD0530, including any of the following: * Gastrointestinal tract disease resulting in an inability to take oral medication or a requirement for IV alimentation * Active peptic ulcer disease * Short gut syndrome * Malabsorption syndrome of any type * Total or partial bowel obstruction * Inability to tolerate oral medications * No history of allergic reactions attributed to compounds of similar chemical or biologic composition to AZD0530 * No QTc prolongation (defined as a QTc interval ≥ 460 msec) or other significant electrocardiogram (ECG) abnormalities * No poorly controlled hypertension (i.e., systolic blood pressure \[BP\] ≥ 140 mm Hg or diastolic BP ≥ 90 mm Hg) * No history of ischemic heart disease, including myocardial infarction * No concurrent cardiac dysfunction including, but not limited to, any of the following: * Symptomatic congestive heart failure * Unstable angina pectoris * Cardiac arrhythmia * No other concurrent uncontrolled illness, including ongoing or active infection or psychiatric illness/social situations, that would limit compliance with study requirements * Prior chemotherapy allowed provided it was administered as part of initial curative intent therapy (i.e., neoadjuvant therapy, adjuvant therapy and/or concurrently with radiotherapy) in combination with surgery * At least 4 weeks since prior chemotherapy * At least 4 weeks since prior and no more than 1 line of palliative chemotherapy for advanced disease * At least 4 weeks since prior radiotherapy and recovered * At least 4 weeks since prior major surgery and recovered * No cytochrome 450 3A4 (CYP3A4) active agents or substances for ≥ 7 days before, during, and for ≥ 7 days after completion of study treatment * No other concurrent investigational agents * No other concurrent anticancer therapy * No concurrent combination antiretroviral therapy for human immunodeficiency virus (HIV)-positive patients