Personalized Long-course Radiotherapy Plus Chemotherapy With or Without Immunotherapy for LARC: PALACE Study

Inclusion Criteria14

• Age: ≥18 years old; sex is not limited.
• Patients with stage II/III rectal cancer staged under MRI or endoscopic ultrasonography and have at least one risk factor: cT4a and invasion of intestinal lumen for more than 1/2 week (measured by MRI)；cT4b(resectable)；cT3c-d with EMVI+ (upper middle rectum)；cN2；MRF+ (≤2mm)；lower rectal cancer is located on the anterior wall and tumor reaching T3 and occupying the intestinal cavity for more than 1/2 week; lower rectal cancer is mainly located on the lateral posterior wall need invading the intestinal wall (anal sphincter) ≥ 5mm； tumor of lower rectal cancer invades the external anal sphincter or levator ani muscle (stage 4) . \[According to the 8th edition of the 2018 AJCC Cancer Staging Manual and the 2008 ESMO Lower Segment Colorectal Cancer Staging Criteria\] . The preoperative T stage is referred to endoscopic ultrasonography or rectal MRI. The N stage is referred to abdominal CT. The M stage is referred to abdominal and thoracic CT. If symptoms occur, other appropriate imaging examinations are needed (cranial MRI or ECT) . Patients with contraindications to MRI can be interpreted with caution based on CT and endoluminal ultrasound staging. MDT should review the staging of all patients.
• The lower edge of lesion is less than 10cm from anal verge according to rigid sigmoidoscopy or rectal digital examination.
• No distant metastasis after a thorough examination .
• Pathological diagnosis of rectal adenocarcinoma,and Immunohistochemistry and/or genetic testing for MSS/pMMR;
• ECOG score: 0-1.
• Patients with primary rectal cancer who had not received surgery prior to surgery (except for palliative ileostomy or colostomy), radiotherapy, systemic chemotherapy or other anti-tumor therapy.
• The main organ function is normal, including the following characteristics:
• ①Blood routine examination: HB ≥9g/dL, WBC ≥ 3.5/4.0×109/L，NE≥ 1.5×109/L，PLT≥ 100×109/L
• ②Biochemical examination：Crea and BIL ≤ 1.0 upper normal limit（ULN），ALT and AST≤ 2.5 upper normal limit（ULN）, ALP≤2.5×UNL，Tbil≤1.5×UNL。
• Not allergic to 5-Fu or Platinum.
• The site of radiotherapy had not previously received radiation.
• If female and of childbearing potential, have a negative result on a pregnancy test performed a maximum of 7 days before initiation of study treatment. If female and of childbearing potential, or if male, agree to use adequate contraception (eg, abstinence, intrauterine device, oral contraceptive, or double-barrier method) based on the judgment of the investigator or a designated associate from the date on which the ICF (Informed Consent Form) is signed until 8 weeks after the last dose of study drug.
• Participants are volunteered to participate in this study, sign informed consent, good compliance, cooperation with follow-up.