Short-course Radiotherapy Combined With CapeOx and PD-1 Inhibitor After Local Excision for High-risk Early Rectal Cancer (TORCH-LE)

Inclusion criteria

• age 18-75 years old, female and male
• pathological confirmed adenocarcinoma
• the distance from anal verge ≤ 7 cm
• pT1 after local excision of the primary rectal cancer, with at least one of the high-risk features including margin positivity/very close margin (\<1mm) at time of local excision, depth of invasion \>1 mm or SM3 invasion (submucosal invasion to the lower third of the submucosal level), high grade or poorly differentiated, lymphovascular invasion, perineural invasion, tumour budding, or pT2 tumor.
• refuse radical surgery
• without pelvic or distance metastases
• KPS \>=70
• with good compliance
• microsatellite repair status is MSS/pMMR
• without previous anti-cancer therapy or immunotherapy
• signed the inform consent

Exclusion criteria

• pregnancy or breast-feeding women
• pathological confirmed signet ring cell carcinoma
• history of other malignancies within 5 years
• serious medical illness, such as severe mental disorders, cardiac disease, uncontrolled infection, etc.
• immunodeficiency disease or long-term using of immunosuppressive agents
• baseline blood and biochemical indicators do not meet the following criteria: neutrophils≥1.5×10\^9/L, Hb≥90g/L, PLT≥100×10\^9/L, ALT/AST ≤2.5 ULN, Cr≤ 1 ULN
• DPD deficiency
• allergic to any component of the therapy