Epirubicin Hydrochloride, Cisplatin, and Fluorouracil or Capecitabine With or Without Lapatinib Ditosylate as First-Line Therapy in Treating Patients With Stomach Cancer or Gastroesophageal Junction Cancer

DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the stomach or the esophagogastric junction

  • Metastatic disease OR not amenable to curative surgery
• Tissue material for HER2 and EGFR assessment must be available
• Positive HER2 status by immunohistochemistry (IHC) OR positive EGFR by either fluorescence in situ hybridization (FISH) or IHC at time of randomization
• No clinical signs of CNS involvement

PATIENT CHARACTERISTICS:

• WHO performance status 0-1
• WBC > 3 x 10^9/L
• Absolute neutrophil count > 1.5 x 10^9/L
• Platelet count > 100 x 10^9/L
• Hemoglobin > 9 g/dL
• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST/ALT ≤ 3 times ULN (≤ 5 times ULN in case of liver metastases)
• Serum creatinine ≤ 2.0 mg/dL
• Creatinine clearance ≥ 60 mL/min
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 1 month after completion of study therapy
• LVEF normal by MUGA scan or ECHO
• No serious cardiac illness within the past 6 months
• No previous or concurrent malignancies except for adequately treated cone-biopsied carcinoma in situ of the cervix or basal cell carcinoma of the skin
• Able to swallow and retain oral medication
• No history or evidence of interstitial pneumonitis or pulmonary fibrosis
• No uncontrolled infections or serious illnesses, malabsorption syndrome, or medical conditions including chronic alcohol abuse, hepatitis, HIV, and/or cirrhosis
• No psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol or follow-up schedule

PRIOR CONCURRENT THERAPY:

• At least 12 months since prior neoadjuvant or adjuvant chemotherapy
• No other investigational drugs from 28 days prior to the first dose of study treatment until 30 days after the last dose of study treatment
• At least 30 days since prior and no concurrent drugs or herbal constituents known to be inducers or inhibitors of CYP3A4
• No prior palliative systemic chemotherapy
• No prior EGFR pathway-targeting therapy (e.g., antibodies or tyrosine kinase inhibitors)
• No concurrent traditional Chinese medicines
• No concurrent non-drug therapies such as radiotherapy (other than for pain relief) or surgery
• No other concurrent anticancer therapy or investigational agents
• No concurrent grapefruit or its juice