Application and Exploration of Personalized ctDNA-MRD Detection Technology in Predicting the Efficacy of Neoadjuvant Therapy for Rectal Cancer

Trial statusRecruiting
Trial phaseNot listed
Trial typeObservational
Biological sexAll
Age18-75
SponsorBeijing Friendship Hospital

About this trial

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.

Eligibility criteria

This trial does not accept healthy volunteers

Qualifiers

1: Signed a written informed consent form and voluntarily participated in this study

2: Aged 18-75 years, regardless of sex

3: Histopathologically confirmed rectal adenocarcinoma

4: Clinical stage II-III as assessed by MRI (according to the AJCC 8th edition)

Disqualifiers

1: History of allergy to monoclonal antibodies, any component of tislelizumab, or capecitabine

2: Prior or ongoing receipt of any tumor-directed surgery, radiotherapy, chemotherapy, targeted therapy, immunotherapy, etc

3: Presence of any active autoimmune disease or history of autoimmune disease

4: History of immunodeficiency, including a positive HIV test result, other acquired or congenital immunodeficiency disorders, or history of organ transplantation or allogeneic bone marrow transplantation

Trial population

"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."

Trial design

Design model

Cohort

Time perspective

Prospective

Treatments tested in this trial

  • Personalized ctDNA-MRD Detection

    Diagnostic test

    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.

Treatment groups

60 Participants
are divided into 1 treatment group
Group A: Rectal Cancer ctDNA-MRD Detection Cohort1 intervention

Trial outcomes

Primary outcomes

1

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)

Secondary outcomes

1

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)
2

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
3

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)
4

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.

Other outcomes

Sponsors and contacts

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