Neoadjuvant Tislelizumab With Chemotherapy for the Treatment of MSS Colon Cancer

Inclusion Criteria:

• Age ≥18 years old and ≤75 years old.

• Pathologically diagnosed MSS ((confirmed by microsatellite stable detection ornext-generation target sequencing) or (confirmed by immunohistochemistry)) colonadenocarcinoma.

• The lower edge of the tumor is more than 12cm from the anus as measured bycolonoscopy and the lower edge of the tumor cannot be directly palpated duringrectal examination.

• Enhanced CT stage T4 or T1-4 N+ without multiple primary tumors or distantmetastasis.

• The Eastern Cooperative Oncology Group physical status score is 0-1.

• Life expectancy is expected to be more than 1 year.

• First diagnosis, no previous anti-tumor treatment received, and no chemotherapycontraindications.

• Appropriate organ function is defined as follows: Hemoglobin level ≥ 90g/L,Neutrophil count ≥ 1.5×10^9/L, Platelet count ≥ 75×10^9/L, Serum total bilirubin ≤ 1.5× the upper limit of normal (UNL), Aspartate aminotransferase (AST) ≤ 2× UNL,Alanine aminotransferase (ALT) ≤ 3× UNL, Serum creatinine ≤ 1.5× UNL.

• Informed consent, able to understand the study protocol and willing to participatein the study, and will provide written informed consent.

Exclusion Criteria:

• Enhanced CT stage (T1-3N0M0)

• Multifocal colorectal cancer.

• CT or MRI in the mid-sagittal plane shows that the lower border of the tumor isbelow the line connecting the sacrococcygeal promontory and the upper border of thepubic symphysis.

• Tumor obstruction or high risk of obstruction, bleeding, and/or perforationrequiring emergency surgery or stent placement.

• Cannot tolerate chemotherapy or immunotherapy, such as but not limited to bonemarrow suppression.

• History of malignant tumors, except for basal cell carcinoma, papillary thyroidcarcinoma, and various in situ cancers.

• Acute exacerbation of important organ diseases (such as but not limited to chronicobstructive pulmonary disease, coronary heart disease, and renal insufficiency)and/or severe acute infectious diseases (such as but not limited to hepatitis,pneumonia, and myocarditis), American Society of Anesthesiologists score > 3 points.

• Mental disorders, illiteracy, or language communication barriers that prevent theunderstanding of the study protocol.

• Peripheral sensory neuropathy, unable to receive oxaliplatin-based chemotherapy.

• Continuous use of glucocorticoids for more than 3 days within 1 month prior tosigning the informed consent form, or having comorbidities requiring the use ofglucocorticoid therapy.

• Unable to undergo enhanced CT examination

• Pregnancy or lactation.

• Refused to participate in this study.

• Other situations in which the researcher deems unsuitable for this study.