RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Radiation therapy uses high-energy x-rays to damage tumor cells. Combining chemotherapy, radiation therapy, and surgery may kill more tumor cells.

PURPOSE: Phase II trial to study the effectiveness of chemotherapy, surgery, and radiation therapy in treating patients with gastric cancer.

OBJECTIVES: I. Evaluate the tolerability and toxic effects of neoadjuvant cisplatin plus paclitaxel and postoperative chemoradiation therapy with fluorouracil plus leucovorin calcium in patients with high-risk gastric cancer. II. Assess the pathologic response of gastric tumors to neoadjuvant cisplatin plus paclitaxel chemotherapy, and preliminarily assess the patterns of failure and disease free and overall survival.

OUTLINE: Patients receive 3 courses of preoperative neoadjuvant chemotherapy given on day 1 every 21 days. Courses consist of an intravenous infusion of cisplatin and a 3 hour intravenous infusion of paclitaxel on day 1. Patients then undergo surgery for tumor removal on day 63, followed 4-6 weeks later by one course of daily intravenous bolus leucovorin calcium and fluorouracil for 5 days. Chemotherapy is repeated 4-6 weeks later for the first 4 days of week 1 and the last 3 days of week 5 of radiation therapy given 5 days a week for 5 weeks. Patients receive two more courses, 4 weeks apart, of fluorouracil and leucovorin calcium for 5 days 4-6 weeks after completing radiation treatment. Patients are followed every month for the first 3 months, every 3 months for the next 21 months, every 6 months for the next year, and annually thereafter.

PROJECTED ACCRUAL: Approximately 30-42 patients will be accrued over 18 months.

• Drug: cisplatin
• Drug: fluorouracil
• Drug: leucovorin calcium
• Drug: paclitaxel
• Procedure: surgical procedure
• Radiation: radiation therapy

DISEASE CHARACTERISTICS: Histologically confirmed adenocarcinoma of the stomach or gastroesophageal junction Localized cancer that is potentially curable by surgery (T2, N1-2, M0 or T3-4, any N, M0) No metastatic cancer to the ovaries

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Hematopoietic: WBC at least 4,000 cells/mm3 Platelet count at least 150,000/mm3 Hepatic: Bilirubin less than 2 mg/dL Renal: Creatinine no greater than 1.5 mg/dL Creatinine clearance greater than 50 mL/min Other: No clinically significant auditory impairment Caloric intake must be at least 1500 kcal/day No prior history of cancer within the past 5 years except for basal cell carcinoma of the skin or in situ carcinoma of the cervix Not pregnant or lactating Fertile patients must use adequate contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior radiation therapy, except for skin cancer Surgery: See Disease Characteristics