CGA Guided Ultrafractionated RT and Systemic Treatment in Elderly or Frail Patients with Inoperable Localized CRC

Inclusion Criteria:

1. ≥70y, or, ≥60 and \<70y but ECOG≥2;
2. male or female;
3. Pathologically confirmed Colorectal adenocarcinoma;
4. any distance from anal verge;
5. Clinical stage ≥T2 and/or N+, without distance metastases;
6. refuse radical operation, physiologically or technically inoperable;
7. No previous radiotherapy in the same field；
8. No chemotherapy prior to enrollment;
9. No immunotherapy prior to enrollment;
10. With good compliance during the study
11. Signed written informed consent

Exclusion Criteria:

1. Known history of other malignancies within 3 years，except cured skin cancer, cervical cancer in situ or thyroid carcinoma.
2. Individuals with a history of uncontrolled epilepsy, central nervous system disease, or psychiatric disorders that, in the judgment of the investigator, are of such clinical severity that they may prevent the signing of an informed consent form or affect the patient's adherence to oral medications
3. Individuals with clinically serious (i.e., active) heart disease, such as symptomatic coronary artery disease, New York Heart Association (NYHA) class II or worse congestive heart failure or severe arrhythmia requiring pharmacologic intervention, or history of myocardial infarction within the last 12 months
4. Individuals with a history of organ transplantation requiring immunosuppressive therapy and long-term hormone therapy
5. Individuals with autoimmune diseases
6. Individuals with severe uncontrolled recurrent infections, or other severe uncontrolled concomitant diseases
7. Baseline hematology and biochemistry did not meet the following criteria: Hb≥90g/L; NEU ≥1.5×109/L; PLT ≥100×109/L; ALT, AST ≤2.5 times the upper limit of normal; ALP ≤2.5 times the upper limit of normal; TB \<1.5 times the upper limit of normal; Cr \<1 time the upper limit of normal; Alb ≥30g/L
8. Individuals allergic to any drug component of the study