The Effect of Preoperative Docetaxel, Cisplatin and Capecitabine on Serum RUNX3 Hypermethylation Status in Patients With Gastric and Lower Oesophagus Adenocarcinoma

Inclusion Criteria: * Patients must have histologically or cytologically confirmed adenocarcinoma of the stomach or lower third of the oesophagusthat considered to be stage II (through the submucosa) or higher, with no evidence of distant metastases, or locally advanced inoperable disease, as evaluated by computed tomography, chest radiography, ultrasonography, or laparoscopy. * Patients must have evaluable or 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 CT scan. * Age \>= 18 years. Because no dosing or adverse event data are currently available on the use of DCX in patients \<18 years of age, children are excluded from this study. * ECOG performance status \<= 1 (see Appendix A). * Patients must have normal organ and marrow function as defined below: X leukocytes \>= 3,000/mcL X absolute neutrophil count \>= 1,500/mcL X platelets \>= 100,000/mcL X total bilirubin within normal institutional limits X AST(SGOT)/ALT(SGPT) \<= 2.5 X institutional upper limit of normal X creatinine within normal institutional limits * The effects of DCX on the developing human fetus at the recommended therapeutic dose are unknown. For this reason, 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 and for the duration of study participation. Should a woman become pregnant or suspect she is pregnant while participating in this study, she should inform her treating physician immediately. * Ability to understand and the willingness to sign a written informed consent document. Exclusion Criteria: * Patients who have had prior chemotherapy or radiotherapy. * Patients may not be receiving any other investigational agents. * Patients with stage I or IV cancer of the stomach or lower oesophagus. * History of allergic reactions attributed to compounds of similar chemical or biologic composition to docetacel, cisplatin or capecitabine. * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. * Pregnant women are excluded from this study because agents use in the study may cause fetal harm. * HIV-positive patients on combination antiretroviral therapy are ineligible because of the potential for pharmacokinetic interactions with docetaxel. In addition, these patients are at increased risk of lethal infections when treated with marrow-suppressive therapy.