A follow-up survey of survivals (Oct. 1 '80 to May 1, '84) in a randomized controlled study (Aug. '79 to Sept. 30' 80) of lentinan in combination administration with chemotherapeutic agents such as 5FU + mitomycin C or tegafur on patients with advanced or recurrent gastrointestinal cancer has shown that lentinan has been effective in such cases with regard to the following facts: 1) A life span prolongation effect at the end-point has been observed with statistical significance in lentinan treated patients as was found in the phase III study. 2) Using the life table analysis method, a higher rate of survival has been observed in the lentinan treated group, especially in combination with tegafur for gastric cancer, clearly showing such high survival rates as 12.97% (P less than 0.05) at two years after, and 9.51% (P less than 0.05) and 3.81%, at three and four years after respectively, and for colorectal cancer, 9.10% and 4.55% at two years and three years after, respectively.