DISEASE CHARACTERISTICS:

• Histologically confirmed metastatic neuroendocrine neoplasm OR primary neuroendocrine tumor with clear clinical evidence of metastases

  • No anaplastic or high-grade histology
• Measurable disease

• Radiographic evidence of disease progression within the past 60 weeks after prior systemic therapy, chemoembolization, embolization, or observation and defined as 1 of the following:

  • Appearance of a new lesion
  • At least 20% increase in the longest diameter (LD) of any previously documented lesion OR an increase in the sum of the LDs of multiple lesions in aggregate of 20%
• No thyroid carcinoma of any histology or pheochromocytoma/paraganglioma
• No known brain metastases

PATIENT CHARACTERISTICS:

Age

• 18 and over

Performance status

• ECOG 0-2

Life expectancy

• At least 24 weeks

Hematopoietic

• Absolute neutrophil count at least 1,000/mm^3
• Platelet count at least 75,000/mm^3
• Hemoglobin at least 8.0 g/dL

Hepatic

• Bilirubin no greater than 2 times upper limit of normal (ULN)
• Alkaline phosphatase no greater than 3 times ULN*
• AST no greater than 3 times ULN* NOTE: *5 times ULN if liver metastases are present

Renal

• Creatinine no greater than 1.5 times ULN

Cardiovascular

• No symptoms of congestive heart failure
• No unstable angina pectoris
• No cardiac arrhythmia

Gastrointestinal

• No gastrointestinal tract disease resulting in an inability to take oral medication (e.g., dysphagia or inability to swallow capsules intact)
• No requirement for IV alimentation
• No active peptic ulcer disease

Ophthalmic

• No known abnormality of the cornea, such as any of the following:

  • History of dry eye syndrome or Sjögren's syndrome
  • Congenital abnormality
  • Abnormal slit-lamp examination using a vital dye (e.g., fluorescein or Bengal-rose)
  • Abnormal corneal sensitivity test (e.g., Schirmer test)

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No ongoing or active infection
• No psychiatric illness or social situation that would preclude study compliance
• No other uncontrolled illness
• No other invasive malignancy within the past 3 years except adequately treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy

• At least 4 weeks since prior interferon injection

Chemotherapy

• At least 4 weeks since prior chemotherapy

• No more than 1 prior systemic chemotherapy regimen

  • Chemoembolization is not considered systemic chemotherapy
• No concurrent chemotherapy

Endocrine therapy

• At least 2 weeks since prior short-acting octreotide injection (6 weeks for long-acting injection)
• Concurrent octreotide allowed provided a stable dose has been administered for at least 1 month and there is documented tumor progression on the current dose with no plan for increasing the dose

Radiotherapy

• At least 3 weeks since prior radiotherapy
• No concurrent radiotherapy

Surgery

• At least 4 weeks since prior major surgery

Other

• Recovered from prior therapy
• At least 4 weeks since other prior systemic therapy
• At least 4 weeks since prior hepatic artery embolization/chemoembolization

• More than 7 days since prior administration of the following CYP3A4 inducers:

  • Phenytoin
  • Carbamazepine
  • Barbiturates
  • Rifampin
  • Oxcarbazepine
  • Rifapentine
  • Modafinil
  • Hypericum perforatum (St. John's wort)
• No prior procedures adversely affecting intestinal absorption
• No prior epidermal growth factor-targeted regimens (e.g., erlotinib, EKB-569, or gefitinib)
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent investigational treatment
• No concurrent CYP3A4 inducers