DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the breast

  • Metastatic disease

• At least 1 objective measurable disease parameter

  • No prior radiotherapy to only site of measurable disease
• Must have received prior anthracycline therapy (e.g., doxorubicin or epirubicin) in the adjuvant/neoadjuvant setting and/or for metastatic disease
• Must have received prior taxane therapy (e.g., paclitaxel or docetaxel) for metastatic disease OR relapsed while receiving adjuvant taxane therapy
• Progressive disease during or within 30 days after receiving prior taxane therapy
• No prior or concurrent brain metastases

• Hormone receptor status:

  • Not specified

PATIENT CHARACTERISTICS:

Age

• Over 18

Sex

• Female

Menopausal status

• Not specified

Performance status

• ECOG 0-2

Life expectancy

• Not specified

Hematopoietic

• Granulocyte count > 1,500/mm^3
• Platelet count > 100,000/mm^3

Hepatic

• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST and ALT ≤ 3 times ULN (5 times ULN if there is liver involvement by tumor)

Renal

• Creatinine ≤ 1.5 mg/dL OR
• Creatinine clearance ≥ 60 mL/min

Cardiovascular

• No symptomatic cardiovascular disease

Gastrointestinal

• No chronic nausea and vomiting
• No complete or partial bowel obstruction
• No dysphagia or odynophagia with inability to swallow pills

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No other malignancy within the past 5 years except curatively treated basal cell or squamous cell skin cancer or carcinoma in situ of the cervix
• No greater than grade 1 neuropathy
• No ongoing or active infection
• No other chronic medical or psychiatric illness that would preclude study participation or compliance
• No other concurrent uncontrolled illness

PRIOR CONCURRENT THERAPY:

Biologic therapy

• Not specified

Chemotherapy

• See Disease Characteristics
• No prior capecitabine for metastatic disease
• No prior fluorouracil for metastatic disease

Endocrine therapy

• At least 1 week since prior hormonal therapy in the metastatic or adjuvant/neoadjuvant setting

Radiotherapy

• See Disease Characteristics
• At least 4 weeks since prior radiotherapy
• Prior radiotherapy to the conserved breast, to the postmastectomy chest wall, or to a limited field involving less than 25% of marrow-containing bone allowed
• No other prior radiotherapy
• No concurrent radiotherapy

Surgery

• No prior organ allograft

Other

• At least 4 weeks since prior cytotoxic drugs
• No prior tipifarnib
• No other prior farnesyl transferase inhibitors
• No prior immunosuppressive therapy
• No more than 3 prior cytotoxic regimens for metastatic disease
• No concurrent enzyme-inducing anticonvulsant medications (e.g., phenobarbital or phenytoin)

• No concurrent warfarin adjusted to an elevated INR

  • Concurrent prophylactic low-dose warfarin (e.g., 1 mg daily) allowed provided PT and INR are normal