Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically proven unresectable, locally advanced or metastatic
adenocarcinoma of the stomach or gastroesophageal junction

- No known brain metastases

- Negative brain imaging required for neurologic signs and symptoms

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- Zubrod 0-1

Life expectancy:

- Not specified

Hematopoietic:

- Absolute neutrophil count at least 1,500/mm^3

- Platelet count greater than 100,000/mm^3

Hepatic:

- Bilirubin no greater than upper limit of normal (ULN)

- SGOT or SGPT no greater than 1.5 times ULN (5 times ULN if liver tumor present)

Renal:

- Creatinine no greater than ULN

Other:

- Not pregnant or nursing

- Fertile patients must use effective contraception

- Must be able to swallow oral medication

- No AIDS syndrome or HIV-associated complex

- No other malignancy within the past 5 years except adequately treated basal cell or
squamous cell skin cancer, carcinoma in situ of the cervix, or adequately treated
stage I or II cancer in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- No prior biologic therapy

- No concurrent biologic therapy

Chemotherapy:

- No prior chemotherapy for advanced or metastatic gastric cancer

- At least 6 months since prior chemotherapy as adjuvant or radiation sensitizer

Endocrine therapy:

- Not specified

Radiotherapy:

- At least 1 month since prior radiotherapy and recovered

- No concurrent radiotherapy

Surgery:

- At least 3 weeks since prior major surgical resection of intra-abdominal organs and
recovered