Study For Patients With Untreated Gastric Cancer Who Will Receive Capecitabine And Lapatinib

Inclusion Criteria:

- Has signed inform consent

- Untreated, newly diagnosed, advanced metastatic or unresectable gastric cancer,
including the gastro-esophageal junction

- Tumor accessible to and patient consent for endoscopic biopsy at study start and
after 7 days of single agent Lapatinib

- Measurable disease according to RECIST criteria

- Male or female > or = 18 years of age

- Cardiac ejection fraction within the institutional range of normal as measured by
echocardiogram

- must have adequate organ function as defined by baseline laboratory values

Exclusion Criteria:

- Gastric carcinoid, sarcomas, or squamous cell cancer

- Pregnant or lactating females

- Intractable nausea, vomiting, or gastro intestinal obstruction requiring
decompression and drainage with a gastric tube or nasogastric suction.

- patients who require continuous enteral feeding

- Malabsorption syndrome or uncontrolled inflammatory GI disease (Crohn's or ulcerative
colitis

- Known history of uncontrolled or symptomatic angina, arrhythmias, or congestive heart
failure