Clinical Application of Circulating Tumor DNA (ctDNA) in Patients With Late-stage Breast Cancer

Study Overview
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Brief Summary
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This is a retrospective, observational, multi-center clinical study of circulating tumor DNA (ctDNA) application in late-stage breast cancers.

Detailed Description
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This study aims to evaluate the feasibility of plasma ctDNA mutation spectrum and clonal spectrum in late-stage metastatic breast cancer patients. Meanwhile, this study tries to establish a model of ctDNA subtyping system to evaluate the molecular load of tumor, to evaluate the curative effect comprehensively and to detect the disease progression in advance. In addition, the investigators plan to explore the clonal evolution of ctDNA in patients with progressive disease (PD), and to monitor the changes of tumor heterogeneity from the molecular level, so as to provide reference for the analysis of drug sensitivity.

Official Title
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Clinical Application of Circulating Tumor DNA (ctDNA) to Monitor the Molecular Tumor Burden in Patients With Late-stage Breast Cancer

Conditions
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Metastatic Breast Cancer, Circulating Tumor DNA, Gene Abnormality

Intervention / Treatment
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* Diagnostic Test: ctDNA testing


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Recent progression of TNBC after multiple lines of chemotherapy or of HR+ or HER2+ MBC after multiple lines of endocrine or targeted therapy; No available recommendation for the next treatment regimen; An Eastern Cooperative Oncology Group (ECOG) performance status of 0 to 2; An updated, available pathological HR/HER2 status for metastasis; According to RECIST 1.1 standard, there should be at least one measurable target lesion; The expected survival time is > 3 months; Those aged 18-70 years old; Liver and kidney function and blood routine test meet the following conditions: Neutrophil > 2.0g/l, Hb > 9g / L, PLT > 100g / L; ALT and AST < 2.5ULN; TBIL < 1.5ULN; Cr < 1.0ULN Signing informed consent; Those willing to accept polygenic testing. Exclusion Criteria: Patients with multiple primary tumors; Those who are unable to obtain blood samples; Those with a history of immunodeficiency or organ transplantation; Those with abnormal cardiac function or previous history of myocardial infarction or serious arrhythmia; The researchers think it is not suitable to participate in this experiment.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Patients with late-stage metastatic breast cancers.<br>This cohort included patients with late-stage metastatic breast cancers and their disease progressed after at least two-line treatment. | Diagnostic Test: ctDNA testing<br>* ctDNA testing was performed for late-stage metastatic breast cancer patients to trace their ctDNA abnormality.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| ctDNA change index | The dynamic change of the frequency spectrum of ctDNA mutation in plasma. | From the date of recruitment until the date of first documented progression or date of death from any cause, whichever came first, assessed up to 12 months. |