The aim of the current study is to determine the effects of Fisetin supplementation on nutritional status, inflammatory and oxidative factors, matrix metalloproteinase enzymes and tumor markers including CA19-9, CEA and thymidine kinase1 in colorectal cancer patients receiving adjuvant chemotherapy in association with TYMS and MTHFR genes polymorphism. Forty two post-surgical colorectal cancer patients receiving chemotherapy regimens will be randomized into following two groups: Fisetin (A) and placebo(B). Group A and B will receive 100 mg Fisetin or placebo capsules every day for consecutive seven weeks, respectively. The intervention will be started seven days before the chemotherapy. Before the intervention, demographic characteristics of the participants will be collected. Further, 24h-food recall, PG-SGA, quality of life ( EORTC QLQ-CR29) and BMI of the subjects will be assessed using conventional methods. Furthermore, 10cc blood samples will be obtained after an overnight fasting at the end of intervention for subsequent determination of serum MDA,TAC,IL8, matrix metalloproteinases enzymes -7,9 and tumor markers of CA19-9, CEA and thymidine kinase. Finally, DNA will be extracted from the blood samples and polymorphism status of TYMS and MTHFR will be determined using PCR-RFLP.