Neoadjuvant Chemoradiation With Nal-IRI and Capecitabine Guided by UGT1A1 Status in Patients With Rectal Cancer

Inclusion Criteria:

* Age: 18\~75 years old.
* Eastern Cooperative Oncology Group (ECOG) performance status of 0\~1.
* Histopathologically confirmed rectal adenocarcinoma.
* The lower edge of the primary tumor is located below the peritoneal reflection or located ≤ 10 cm above the anal verge.
* Clinical stage: T3-4NanyM0 or T1-2N+M0.
* Adequate bone marrow function as evidenced by: Absolute neutrophil count (ANC) ≥1.5×10\^9/L, Platelet count ≥100×10\^9/L, Hemoglobin (Hb) ≥90 g/L.
* Adequate hepatic function as evidenced by: Total bilirubin ≤1.5 × upper limit of normal (ULN), Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) ≤2.5×ULN, Serum albumin ≥3 g/dL.
* Adequate renal function as evidenced by: Serum creatinine (Cr) ≤1.5 × ULN or creatinine clearance ≥60 mL/min.
* Be willing to undergo UGT1A1 gene testing and UGT1A1 genotype of \*1\*1 or \*1\*28.
* Accept the neoadjuvant chemoradiotherapy protocol of this study and sign the informed consent.

Exclusion Criteria:

* Any other malignancy within 5 years, with the exception of cured in-situ carcinoma or basal cell carcinoma etc.
* Active, uncontrolled bacterial, viral, or fungal infections that require systemic treatment.
* Active HIV infection.
* Combined with uncontrollable systemic diseases.
* History of allergy or hypersensitivity to drug or any of their excipients.
* Any clinical indicators indicating contraindications to radiotherapy/chemotherapy and surgery.
* Use of strong inhibitors or inducers of CYP3A, CYP2C8 and UGT1A1.
* Pregnant or breastfeeding women, or subjects of childbearing age who refuse contraception.
* Patients with poor cognitive abilities who are unable to answer questions, fill out questionnaires, or have mental disorders.
* Patients who do not meet the inclusion criteria; patients who meet the inclusion criteria but are not suitable to participate in this trial judged by the investigator.