Biomarkers for Predicting Neoadjuvant Chemoradio-resistance for Middle-low Advanced Rectal Cancer

Identification of Tissue Biomarkers for Predicting Neoadjuvant Chemoradio-resistance in Patients With Middle-low Local Advanced Rectal Cancer.

Neoadjuvant therapy has been widely applied to locally advanced rectal cancer. However, about 50% of patients receiving this therapy do not respond well as evidenced by the fact that their T or N stages are not effectively decreased judged by postoperative pathological examination. The purpose of this trail is to identify the biomarkers (from within patients' tumor mass before neoadjuvant therapy) to predict resistance to neoadjuvant therapy. These biomarkers can help stratify neoadjuvant-resistant patients towards surgery while avoiding unnecessary chemoradio-based neoadjuvant therapy.

According to postoperative pathological examination results, all participants will be divided into two groups: complete response (ypT0N0) and poor response (>ypT1-2N0). Differentially expressed genes between complete response and poor response will be analyzed. A scoring formula will be established based on the results. Tumor tissue samples are collected before neoadjuvant therapy and will be analyzed via RNA sequencing.

Inclusion Criteria:

• Histopathology proved to be adenocarcinoma of the rectum.
• The edge of tumor is within 12cm of anus margin.
• According to the eighth edition of AJCC TNM staging standard ,that staging for Ⅱ-Ⅲ period, as T3-T4, N0 or any T, N1-2.
• There is no history of chemotherapy, radiotherapy or immunotherapy before neoadjuvant therapy.
• Understand and agree to sign the informed consent for the study.

Exclusion Criteria:

• With intestinal obstruction or impending obstruction, or perforation.
• With other malignancies occurred within 5 years.