OBJECTIVES:~Primary~Determine the efficacy of bortezomib in patients with unresectable or metastatic gastric or gastroesophageal junction adenocarcinoma.~Secondary~Determine the toxicity of this drug in these patients.~Determine possible predictors of response to this drug, using pretreatment tumor immunohistochemistry, in these patients.~OUTLINE: This is an open-label, nonrandomized, multicenter study.~Patients receive bortezomib IV over 3-5 seconds on days 1, 4, 8, and 11. Courses repeat every 3 weeks in the absence of disease progression or unacceptable toxicity.~Patients are followed every 3 months for 1 year.~PROJECTED ACCRUAL: A total of 15-33 patients will be accrued for this study within 5-12 months.
RATIONALE: Bortezomib may stop the growth of tumor cells by blocking the enzymes necessary for their growth.~PURPOSE: Phase II trial to study the effectiveness of bortezomib in treating patients who have unresectable or metastatic gastric cancer or gastroesophageal junction adenocarcinoma.