The effect of cognitive behavioral therapy on chemotherapy-induced side effects and immune function in colorectal cancer patients undergoing chemotherapy: study protocol for a randomized controlled trial

Background: Colorectal cancer (CRC) was one of the most widely diagnosed cancers in the United States in 2021. CRC patients may experience significant psychological stress and are susceptible to depression and anxiety. Previous studies have shown that cognitive behavioral therapy (CBT) can reduce fatigue and improve quality of life among breast cancer patients. However, as a non-pharmaceutical treatment, it remains unclear whether CBT improves chemotherapy-induced side effects and immune function in CRC patients. In this study, we will conduct a randomized controlled trial (RCT) among CRC patients undergoing chemotherapy to determine whether CBT can reduce the side effects of chemotherapy and improve the immune function of CRC patients. Methods: The study will be a single-center RCT. CRC patients undergoing chemotherapy will receive either eight sessions of group-based CBT (every 2-3 weeks) or usual care (usual oncology care). Each participant will undergo assessments at baseline (T0), immediately post-intervention (T1), 3 months postintervention (T2), and 6 months post-intervention (T3). The primary outcome will include chemotherapyinduced side effects in CRC patients. The secondary outcome will be immune function (measured by levels of inflammatory cytokines). Other outcomes will include the levels of tumor markers, assessments of psychological status (perception of stress, depression and anxiety, self-efficacy, sleep quality, quality of life, social support condition, and cognitive function), and necessary laboratory examinations (biochemical index and blood cell counts) among CRC patients undergoing chemotherapy. Discussion: Our study will provide clinical evidence regarding whether CBT should be generalized in clinical treatment and the extent to which CBT reduces chemotherapy- induced side effects for CRC patients.