This study will access the safety and efficacy of the Viatar™ Oncopheresis System to remove a meaningful quantity of circulating tumor cells from the blood of subjects' with breast, colon or prostate solid tumor cancers in a single treatment. CTC reduction will be measured as the change in circulating tumor cells as determined before and after treatment.

Inclusion Criteria:

• Confirmed diagnosis of breast, colon or prostate cancer

• No prior cancer therapy or failed first line therapy

• >= 25 CTC per 7.5 mL of blood within 1 week prior to oncopheresis treatment

• > 1 month life expectancy

• Adequate baseline hematological function as assessed by the following laboratory values:

  • Hemoglobin > 9 g/dl
  • Platelets > 100,000/mm3
  • WBC > 3,000/mm3
  • Absolute Neutrophil Count > 1,500/mm3

Exclusion Criteria:

• Coagulation disorders and/or a history of thromboembolic complications, including known hypersensitivity to citrate: e.g., abnormal platelet count, prothrombin time and partial activated thromboplastin time and with a history of deep vein thrombus or pulmonary embolism
• Patients with known immunodeficiency virus (HIV)