Clinical Trial of All-trans-retinoic Acid, Bevacizumab and Atezolizumab in Colorectal Cancer

The main purpose of this clinical trial is to learn about the good and the bad effects of all trans retinoic acid (ATRA), atezolizumab and bevacizumab as a possible treatment for advanced colorectal patients. Participants will be treated with the following combination of these drugs: 1. ATRA will be given in a pill form to be taken twice a day at home for 7 days starting on day 1 of a cycle. 2. Atezolizumab will be given through a vein in arm or through mediport over 60-90 minutes every 2 weeks in the outpatient chemotherapy infusion centers at UTSW. 3. Bevacizumab will be given through a vein in arm or through mediport over 20-40 minutes every 2 weeks in the outpatient chemotherapy infusion centers at UTSW.本临床试验的核心目的为探究全反式维甲酸（all trans retinoic acid, ATRA）、阿替利珠单抗与贝伐珠单抗作为晚期结直肠癌患者潜在治疗方案的疗效与不良反应。受试者将接受以下联合药物治疗方案： 1. 全反式维甲酸以口服片剂形式给药，受试者需于家中每日服药2次，每个治疗周期自第1日起连续服用7天。 2. 阿替利珠单抗通过手臂静脉或植入式输液港输注，输注时长为60~90分钟，每2周给药1次，给药地点为UTSW门诊化疗输液中心。 3. 贝伐珠单抗通过手臂静脉或植入式输液港输注，输注时长为20~40分钟，每2周给药1次，给药地点为UTSW门诊化疗输液中心。