RATIONALE: Bortezomib may stop the growth of tumor cells by blocking the enzymes necessary for their growth.

PURPOSE: Phase II trial to study the effectiveness of bortezomib in treating patients who have recurrent or refractory extensive-stage small cell lung cancer that was previously treated with platinum-based chemotherapy (such as cisplatin, carboplatin, or oxaliplatin).

OBJECTIVES:

• Determine the efficacy of bortezomib, in terms of response rate (confirmed and unconfirmed, complete and partial), in patients with recurrent or refractory extensive stage small cell lung cancer previously treated with platinum-based therapy.
• Determine the qualitative and quantitative toxic effects of this drug in these patients.
• Determine the overall survival of patients treated with this drug.
• Correlate selected molecular markers with outcomes in patients treated with this drug.

OUTLINE: Patients are stratified according to platinum-sensitivity status (platinum sensitive [temporarily closed to accrual as of 8/1/04] vs platinum refractory [temporarily closed to accrual as of 6/1/04]).

Patients receive bortezomib IV over 3-5 seconds on days 1, 4, 8, and 11. Courses repeat every 21 days in the absence of disease progression or unacceptable toxicity.

Patients are followed every 6 months for 2 years.

PROJECTED ACCRUAL: A total of 40-80 patients (20-40 per stratum) will be accrued for this study within 0.5-1 year.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed extensive stage small cell lung cancer

  • Diagnosis by sputum cytology allowed provided it is confirmed by an independent pathologic review
  • Clinical evidence of recurrent or refractory disease does not require a confirmatory biopsy

• Measurable disease by plain radiographs, CT scan, or MRI

  • Prior radiotherapy to measurable disease allowed provided there is evidence of disease progression by CT scan OR there is measurable disease outside of the radiotherapy field

• Must have received a prior platinum-based chemotherapy regimen and meet criteria for 1 of the following:

  • Platinum-sensitive disease, defined as an initial response with subsequent progression more than 90 days after last platinum treatment (temporarily closed to accrual as of 8/1/04)
  • Platinum-refractory disease, defined as no response to or progression during platinum treatment or subsequent progression no more than 90 days after last platinum treatment (temporarily closed to accrual as of 6/1/04)

• Brain and/or leptomeningeal metastases are allowed provided all of the following are true:

  • Asymptomatic on neurological exam
  • No concurrent corticosteroids for symptom control
  • No concurrent enzyme-inducing anticonvulsants (e.g., phenytoin or phenobarbital)

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 at least 100,000/mm^3

Hepatic

• Not specified

Renal

• Creatinine no greater than upper limit of normal OR
• Creatinine clearance at least 60 mL/min

Other

• Not pregnant or nursing
• Fertile patients must use effective contraception
• No symptomatic sensory neuropathy greater than grade 1
• 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 any other adequately treated stage I or II cancer currently in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• See Disease Characteristics
• At least 3 weeks since prior chemotherapy

Endocrine therapy

• See Disease Characteristics

Radiotherapy

• See Disease Characteristics
• At least 3 weeks since prior radiotherapy
• No concurrent radiotherapy to measurable lesions

Surgery

• At least 14 days since prior thoracic or other major surgery and recovered

  • Must have disease outside of the prior surgical resection area OR new lesion must be present