DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed adenoid cystic or other malignant salivary gland carcinoma of major or minor salivary gland origin, meeting 1 of the following criteria:

  • Epidermal growth factor receptor (EGFR) expressing tumors
  • ERBB2 expressing tumors
• Recurrent and/or metastatic disease

• Progressive disease as defined by 1 of the following criteria occurring within in the past 6 months:

  • At least a 20% increase in radiologically or clinically measurable disease
  • Appearance of any new lesions
  • Deterioration in clinical status
• Not amenable to surgery or curative radiotherapy

• Measurable disease

  • At least 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan
  • Lesion must be outside of field of prior local therapy OR disease has progressed within the treatment field

• No symptomatic brain metastases

  • Patients with known brain metastases that have been stable ≥ 3 months since completion of radiotherapy or surgery and who have no significant neurological deficits and are off corticosteroids are eligible

• Tumor lesions accessible for biopsy

  • In the event that tumor biopsy is medically contraindicated exceptions may be granted by the Principal Investigator only

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• More than 12 weeks

Hematopoietic

• WBC ≥ 3,000/mm^3
• Absolute neutrophil count ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3

Hepatic

• Bilirubin normal
• AST and ALT ≤ 2.5 times upper limit of normal

Renal

• Creatinine normal OR
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• Cardiac ejection fraction normal by echocardiogram or MUGA
• No symptomatic congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Gastrointestinal

• Able to swallow and retain oral medication
• No gastrointestinal disease resulting in an inability to take oral medication
• No malabsorption syndrome
• No requirement for IV alimentation
• No uncontrolled inflammatory gastrointestinal disease (e.g., Crohn's disease or ulcerative colitis)

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• Willing and able to undergo tumor biopsy (unless medically contraindicated)
• No other active malignancy within the past 5 years except adequately treated nonmelanoma skin cancer or carcinoma in situ of the cervix
• No history of allergic reaction attributed to compounds of similar chemical or biologic composition to lapatinib
• No other uncontrolled illness
• No ongoing or active infection
• No psychiatric illness or social situation that would preclude study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)

Endocrine therapy

• Not specified

Radiotherapy

• At least 4 weeks since prior radiotherapy, except low-dose, non-myelosuppressive radiotherapy

Surgery

• No prior gastrointestinal surgical procedures affecting absorption
• At least 4 weeks since prior surgery

Other

• Recovered from all prior therapy
• No prior EGFR or ERBB2-targeting therapies
• At least 7 days since prior and no concurrent CYP3A4 inhibitors
• At least 14 days since prior and no concurrent CYP3A4 inducers
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent investigational agents
• No other concurrent anticancer therapy