An observational study in Locally Advanced Rectal Cancer (LARC), sponsored by Beijing Friendship Hospital. Recruiting at 1 site in China. Open to participants aged 18 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-04-21.
Sponsored by Beijing Friendship Hospital · Observational
This study is a single-center, prospective, observational clinical trial enrolling patients with locally advanced rectal cancer (cT3-4aN0M0 and cT1-4aN1-2M0). By collecting tissue and blood samples at multiple timepoints, and integrating multi-omics data including ctDNA mutations, copy number variations, and mtDNA profiles, a multi-omics model will be constructed to predict the efficacy of neoadjuvant therapy for rectal cancer.
This study is a single-center, prospective, observational clinical trial designed to construct and validate a multi-omics-based predictive model for neoadjuvant treatment efficacy in locally advanced rectal cancer. Patients diagnosed with locally advanced rectal cancer (cT3-4aN0M0 and cT1-4aN1-2M0) are enrolled, and tissue and blood samples are dynamically collected at multiple time points. By simultaneously analyzing plasma circulating tumor DNA (ctDNA) somatic mutations, copy number variations, and mitochondrial DNA (mtDNA), a multi-dimensional molecular biomarker system is constructed.The primary objectives of the study include: first, prospectively validating the efficacy of a multi-dimensional molecular biomarker model based on ctDNA mutations, mtDNA, and copy number variations for detecting molecular residual disease (MRD) during neoadjuvant therapy and assessing its sensitivity and specificity in predicting pathological response; second, comparing the sensitivity and specificity of different omics features-ctDNA mutations, mtDNA, copy number variations, alone or in combination-in predicting treatment efficacy after surgery.The secondary objectives are: first, to construct a multi-omics model integrating ctDNA mutations, copy number variations, and mtDNA for dynamically assessing tumor burden changes during neoadjuvant therapy; second, to explore and optimize ctDNA-MRD detection technology, aiming to overcome the high sample volume requirements of traditional methods and improve the detection rate of low-abundance ctDNA.
1,762 studies on the registry are indexed under Rectal Neoplasms; 518 are open to participants now.
This study's planned enrollment of 60 is below the median of 160 across 413 observational studies indexed under Rectal Neoplasms.
Browse Rectal Neoplasms studies →Beijing Friendship Hospital is the lead sponsor of 216 studies on the registry; 95 are open to participants now.
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"Enrolled subjects must be 18-75 years old, pathologically confirmed with rectal adenocarcinoma (MRI stage II-III), with a tumor inferior margin ≤10 cm, resectable via surgery, ECOG performance status 0-1, normal major organ function, no prior relevant treatment, ability to take oral medications, signed informed consent, and no surgical contraindications. Detailed eligibility criteria can be found in the study protocol." "Subjects with a history of drug allergy, prior cancer treatment, active or past autoimmune disease, immunodeficiency, severe heart disease, other malignant tumors (except low-risk ones) within the past five years, pregnancy or lactation, or other factors affecting safety and compliance will be excluded from this study. Detailed eligibility criteria can be found in the study protocol."
Exclusion Criteria:
This study is an exploratory study, with an expected enrollment of 60 patients diagnosed with stage II-III rectal cancer who are scheduled to undergo neoadjuvant therapy. The sample collection and testing procedures are as follows: Before neoadjuvant therapy: Baseline endoscopic biopsy tissue or paraffin sections:1.1 Two pieces of endoscopic biopsy tissue, approximately 2 mm in diameter, are collected and placed in tissue preservation tubes.1.2 Ten unstained tissue slides are prepared. Peripheral blood collection: 10 mL of blood is collected using cell-free DNA blood collection tubes for the following assays:① ctDNA-customized MRD high-depth sequencing;② ctDNA shallow whole-genome sequencing (sWGS) for monitoring copy number variation (CNV) profiles;③ Mitochondrial DNA (mtDNA) analysis. During neoadjuvant therapy (within 2 weeks after radiotherapy completion): Peripheral blood collection: 10 mL of blood is collected using cell-free DNA blood collection tubes for the followin
Diagnostic Test: Personalized ctDNA-MRD Detection
This observational study involves collecting clinical data and biospecimens (peripheral blood and tissue samples) from participants at multiple timepoints. Personalized ctDNA-MRD detection technology, together with copy number variation and mtDNA profiling, is applied to analyze the samples. The primary goal is to predict neoadjuvant therapy efficacy by identifying biomarkers associated with key outcomes, such as tumor regression grade and pathological complete response rate. No experimental drugs or treatments are administered.
Complete Response (CR) rate
The proportion of patients confirmed to have achieved complete response after neoadjuvant therapy, as assessed by endoscopy, imaging (pelvic MRI/chest-abdominal CT), digital rectal examination, and pathological evaluation. The assessment time point corresponds to T2 (8-14 weeks after the end of neoadjuvant therapy). Complete response requires: normal mucosa on endoscopy with negative biopsy; no residual tumor on imaging; no palpable mass on digital rectal examination; and no viable tumor cells in postoperative pathology (if surgery is performed).
Time frame: Post-neoadjuvant Therapy Efficacy Assessment Time Point (within 8-12 weeks after radiotherapy completion)
Complete Response Rate (CR)
The proportion of patients confirmed to have achieved complete response after neoadjuvant therapy, as assessed by endoscopy, imaging (pelvic MRI/chest-abdominal CT), digital rectal examination, and pathological evaluation. The assessment time point corresponds to T2 (8-14 weeks after the end of neoadjuvant therapy). Complete response requires: normal mucosa on endoscopy with negative biopsy; no residual tumor on imaging; no palpable mass on digital rectal examination; and no viable tumor cells in postoperative pathology (if surgery is performed).
Time frame: Post-neoadjuvant Therapy Efficacy Assessment Time Point (within 8-12 weeks after radiotherapy completion)
Major Pathological Response Rate (MPR)
The proportion of patients with ≤10% residual tumor cells and no lymph node metastasis in postoperative pathological examination, assessed at T3 (1 month after radical resection, corresponding to the technical roadmap).
Time frame: 1 month after surgery
Objective Response Rate (ORR)
The proportion of patients who achieve complete response (CR) or partial response (PR) after neoadjuvant therapy, assessed at T2 (8-14 weeks after the end of neoadjuvant therapy). Partial response is defined as a ≥30% reduction in tumor size confirmed by endoscopy and imaging, with no new lesions.
Time frame: Post-neoadjuvant Therapy Efficacy Assessment Time Point (within 8-12 weeks after radiotherapy completion)
Disease-Free Survival (DFS)
The time from the initiation of neoadjuvant therapy to disease recurrence (confirmed by endoscopy/imaging), metastasis, or death from any cause, with follow-up through T4 (surveillance period of 3-6 months, optional) and subsequent long-term follow-up nodes as per the technical roadmap.
Time frame: Monitoring Period: Every 3 or 6 months after treatment completion, continued until 1 year.
Overall Survival (OS)
Time from randomization to death from any cause, recurrence, or metastasis. This serves as a gold-standard endpoint for assessing the long-term efficacy of anticancer therapy.
Time frame: From the randomization date to the date of death from any cause, disease recurrence, or metastasis-whichever occurred first-assessed over the entire study period with a planned maximum follow-up of 12 months.
Organ Preservation Rate (OPR)
The proportion of patients who avoid radical surgery and retain anal function and rectal organ integrity after neoadjuvant therapy, assessed at T3 (1 month after surgery for operated patients, or 1 month after treatment plan confirmation for non-operated patients, corresponding to the technical roadmap).
Time frame: 1 month after surgery
Neoadjuvant Therapy Score for Rectal Cancer (NAR)
At T2 (8-14 weeks after the end of neoadjuvant therapy), the patient's response to neoadjuvant therapy is evaluated using a standardized scoring system that integrates endoscopic findings, imaging regression, and tumor marker levels.
Time frame: Post-neoadjuvant Therapy Efficacy Assessment Time Point (within 8-12 weeks after radiotherapy completion)
Quality of Life (QoL)
Assessed using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) and Colorectal Cancer-Specific Module (EORTC QLQ-CR29) to evaluate physical function, psychological status, and bowel-related quality of life. The EORTC QLQ-C30 uses a 0-100 scale where higher scores in functional domains indicate better function, and higher scores in symptom domains indicate worse symptoms. The EORTC QLQ-CR29 uses a 0-100 scale where higher scores in symptom domains indicate worse bowel/rectal symptoms.
Time frame: Baseline (T0), within 2 weeks after completion of radiotherapy (T1), 8-12 weeks after completion of radiotherapy (T2), and 4 weeks after surgery or after final treatment regimen determination (T3), through study completion, an average of 1 year
Plan to share: Yes
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