Inclusion Criteria:

1. 18 to 60 years old
2. Metastatic breast carcinoma.
3. Histological confirmation of invasive breast carcinoma
4. Complete or partial response to pre-transplant standard-dose chemotherapy, or hormonal therapy. For bone disease, stable disease (SD) is allowed.
5. Patient must have tumor assessed for estrogen-receptor (ER) and progesterone-receptor (PR).
6. Persistent detectable or non-detectable CTCs by Veridex Technology after completion of standard therapy.
7. Zubrod performance status 0 or 1.
8. Patients must have adequate hematological parameters (WBC 3,000/mm3; platelet count 100,000/mm3)
9. Adequate renal function (serum creatinine 1.5mg/dl)
10. Adequate liver function (total bilirubin, SGPT 2 x normal).
11. Adequate cardiac function (LVEF >= 50%).
12. Adequate pulmonary function (DLCO >= 50% of predicted value).
13. Patients must sign an informed consent.

Exclusion Criteria:

1. Prior HDCT with AHST in adjuvant setting.
2. History or presence of brain/leptomeningeal metastasis.
3. History of other malignancies except cured non-melanoma skin cancer or cured cervical carcinoma in situ.
4. Presence of other severe medical illnesses or conditions.
5. Clinically significant active infections.
6. HIV infection.
7. Chronic active hepatitis.
8. Pregnant or lactating women (females of childbearing potential must use adequate contraception).
9. Medical, social or psychologic factors which would prevent the patient from receiving or cooperating with the full course of therapy or understanding the informed consent procedure.