A study was conducted to investigate the effects of long—term administration of the immunomodulatory food modified arabinoxylan from rice bran (BioBran/MGN-3) (also known as Lentin Plus 1000), on 16 cancer patients, mainly in stage IV with various conventional lesions, who had just undergone conventional cancer treatments, such as surgery, chemotherapy and radiotherapy. The main clinical observations were the safety and effect of BioBran on the nutritional state of the patients, who were exhausted due to treatment. During the administration period, no decreases in body weight and leukocyte count or significant changes in leukogram were observed. Rather, the leukocyte count increased. In addition, most patients showed an increase in NK cell activity and a remarkable decrease in tumor markers.