Inclusion Criteria

DISEASE CHARACTERISTICS:

- Diagnosis of locally advanced or metastatic breast cancer

- Recurrent, refractory or progressive disease after receiving prior
anthracycline, taxane, and capecitabine therapy

- Prior anthracycline and taxane therapy may have been as neoadjuvant, or
adjuvant therapy if disease progression is documented within a year of
completing that agent

- Received prior capecitabine therapy for metastatic or recurrent disease

- Measurable disease

- Bone metastases requires other disease present that can be measured

- No brain metastases, unless documented to be controlled post-completion of local
therapy (surgery and/or radiation therapy) for at least 4 weeks

- No meningeal carcinomatosis

- No malignant effusion as the only site of disease recurrence

- Hormone receptor status not specified

PATIENT CHARACTERISTICS:

- Menopausal status not specified

- Performance status of 0-2

- Creatinine ≤ 1.5 mg/dL OR creatinine clearance ≥ 40 mL/min

- Hemoglobin ≥ 10 g/dL

- ANC ≥ 1,500/mm^3

- Platelet count ≥ 100,000/mm^3

- Bilirubin normal or hyperbilirubinemia < grade 1 (unless due to Gilbert syndrome with
elevated total but normal levels of conjugated bilirubin)

- Not pregnant or nursing

- Fertile patients must use effective contraception

- No other non-breast malignancy, except nonmelanoma skin cancer

- No other serious underlying medical condition, that in the opinion of the treating
physician, would make study protocol unreasonably hazardous for the patient or would
preclude the patient's ability to comply with the study protocol

PRIOR CONCURRENT THERAPY:

- See Disease Characteristic

- Recovered from all prior chemotherapy or radiotherapy to NCI CTC grade ≤ 1

- Unlimited documented prior chemotherapy regimens allowed

- No prior irinotecan hydrochloride or etoposide

- No Hypericum perforatum (St. John's wort) 14 days prior to, during, or 7 days after
completion of study therapy

- At least 7 days since prior and no concurrent phenytoin, carbamazepine,
phenobarbital, or any other enzyme-inducing anticonvulsant drug (EIACD)

- No concurrent aprepitant