Outpatients (n = 15) with metastasizing far advanced colorectal cancers received immunotherapy consisting of low-dose cyclophosphamide (LDCY) 300 mg/m2 every 28 days i.v., thymostimulin 30 mg/m2, days 3-10 after low-dose cyclophosphamide i.m. once daily, then twice a week, and echinacin 60 mg/m2