pd-1 antibody following preoperative chemoradiotherapy for locally advanced pmmr/mss rectal cancer

Conditions: Colorectal Carcinoma

Summary: in this open-label phase ii study, patients will be scheduled for neoadjuvant treatment with pd-1 antibody following preoperative chemoradiotherapy with capecitabine for pmmr/mss rectal cancer staged as locally advanced (ct3-t4n+/-m0 for rectal cancer). this treatment will be given during the window period until surgical resection of the tumor.


Eligibility criteria:
inclusion criteria: * patients who personally provided written consent for participation in the study * treatment-naive patients with rectal cancer, in whom the inferior margin of the tumor was at a distance of 12 cm or less from the av before crt * primary rectal cancer histopathologically confirmed to be adenocarcinoma * clinical stage of t3,and t4 ,n any,m0,before crt * macroscopic radical resection could be feasible, based on diagnostic imaging before crt * patients with the ecog performance status of 0 or 1 at the time of enrollment * patients without distant metastasis on the imaging test before crt * preoperative biopsy of tumor immunohistochemistry tps\>1% or cps\>1 * life expectancy of greater than 2 years * no signs of intestinal obstruction; or the obstruction has been relieved after the proximal colostomy operation * hematology: wbc\>4000/mm3; plt\>100000/mm3; hb\>10g/dl * liver function: sgot and sgpt are less than 1.5 times the normal value; bilirubin is less than 1.5mg/dl * renal function: creatinine \<1.8mg/dl others: non-pregnant or breast-feeding women; no other malignant diseases (except for non-melanoma or cervical carcinoma in situ) within 5 years or during the same period; no mental illness that causes the inability to obtain informed consent; no other serious diseases that can shorten the survival time disease. * have not received rectal surgery in the past; * have not received chemotherapy or radiotherapy in the past; * have not received biological treatment in the past; * past endocrine therapy: unlimited. exclusion criteria: * rectal cancer with unstable microsatellite (msi or dmmr); * preoperative biopsy of tumor immunohistochemistry tps≤1% or cps≤1 * known history of human immunodeficiency virus (hiv) or chronic hepatitis b or c (high copy viral dna); * autoimmune diseases; * other active clinical serious infections (\>nci-ctc version 3.0); * patients in clinical phase i; * there is evidence that there is distant metastasis before surgery; * cachexia, decompensation of organ function; * have a history of pelvic or abdominal radiotherapy; * multiple primary cancers; * patients who need treatment for seizures (such as steroids or anti-epileptic treatment); * have a known additional malignant tumors within 5 years. exceptions include basal cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer; * chronic inflammatory bowel disease, intestinal obstruction; * drug abuse and medical, psychological or social conditions may interfere with patients' participation in research or have an impact on the evaluation of research results; * known or suspected to be allergic to the study drug or to any drug given in connection with this test; * any unstable conditions or situations that may endanger patient safety and compliance