An observational study in Malignant Phyllodes Tumor of the Breast, sponsored by Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University. Not yet recruiting at 1 site in China. Open to female participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-10-29.
Sponsored by Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University · Observational
Malignant phyllodes tumor of the breast is a rare fibroepithelial tumor. Patients with metastatic or unresectable disease have limited systemic treatment options, and there remains a need for biomarkers that can dynamically reflect disease changes during treatment. Circulating tumor DNA (ctDNA) may provide additional information on tumor burden and disease progression through a minimally invasive blood-based approach.
This prospective, multicenter, observational cohort study will enroll approximately 50 patients with advanced malignant phyllodes tumors of the breast who have distant metastases or are currently not candidates for curative surgery and are planning to start systemic therapy. Peripheral blood samples will be collected before treatment and at predefined time points during the current systemic treatment line, including time points corresponding to routine imaging assessments. Individualized tumor-informed ctDNA monitoring panels will be established using patient-specific somatic variants identified from tumor whole-exome sequencing obtained during routine clinical care.
The study will primarily evaluate the relationship between dynamic changes in ctDNA during the current systemic treatment line and progression-free survival (PFS), and will explore the potential value of longitudinal ctDNA monitoring for disease monitoring and prognostic assessment in advanced malignant phyllodes tumors. Study ctDNA results will not be used independently to guide clinical treatment decisions.
Malignant phyllodes tumor (MPT) of the breast is a rare fibroepithelial neoplasm with heterogeneous clinical behavior. Patients with metastatic disease or disease that is not amenable to curative surgery have limited systemic treatment options and generally have an unfavorable prognosis. During systemic therapy, there remains a need for biomarkers that can dynamically reflect changes in tumor burden and disease status.
Circulating tumor DNA (ctDNA) contains tumor-derived molecular alterations detectable in peripheral blood and may provide a minimally invasive approach for longitudinal monitoring of tumor burden. Tumor-informed ctDNA assays use patient-specific somatic variants identified from tumor genomic sequencing to establish individualized monitoring panels, allowing longitudinal tracking of molecular changes during treatment. Evidence regarding longitudinal ctDNA monitoring in malignant phyllodes tumors remains limited.
This is a prospective, multicenter, observational, single-cohort study enrolling approximately 50 patients with advanced malignant phyllodes tumors of the breast who have distant metastases or are currently considered unsuitable for curative surgery and who are planning to start systemic therapy. The current systemic treatment line will serve as the principal observation window. Baseline peripheral blood will be collected before initiation of the treatment line, followed by longitudinal blood collection before the second treatment cycle, before the third treatment cycle, and at subsequent time points corresponding to routine CT or MRI assessments. When feasible, an additional blood sample will be collected at radiologically confirmed disease progression.
Individualized tumor-informed ctDNA monitoring panels will be established using patient-specific somatic variants identified from tumor whole-exome sequencing obtained during routine clinical care. A matched normal sample will be collected at the first study blood draw to support filtering of germline variants and signals potentially related to clonal hematopoiesis. Longitudinal ctDNA assessments will include ctDNA detection status, ctDNA level, and plasma variant allele frequency.
The study will focus on the relationship between baseline ctDNA status, early changes in ctDNA during treatment, and ctDNA patterns at blood collection time points corresponding to routine imaging assessments, and progression-free survival (PFS) during the current systemic treatment line. The study aims to provide exploratory evidence regarding the potential value of longitudinal ctDNA monitoring for disease monitoring and prognostic assessment in patients with advanced malignant phyllodes tumors of the breast.
For a small subset of patients who become candidates for surgery or local treatment after systemic therapy, additional perioperative blood sampling may be performed before treatment, 2 to 4 weeks after surgery, and at subsequent imaging assessment time points as an exploratory analysis.
All systemic treatment decisions and routine imaging assessments will be made according to standard clinical practice. Participation in this study will not determine the choice of systemic therapy. Study ctDNA results will not replace standard clinical or imaging assessments and will not be used independently to guide treatment decisions.
Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University is the lead sponsor of 483 studies on the registry; 283 are open to participants now.
Counted across the registry records on this site, refreshed daily.
The study population consists primarily of adult women with pathologically confirmed advanced malignant phyllodes tumors of the breast who have distant metastatic disease or are currently considered unsuitable for curative surgery. Participants will be starting or receiving a current line of systemic therapy and must not have experienced a PFS event at enrollment. The prospective main cohort will include approximately 50 participants. A small number of patients with pre-existing clinical data and archived blood samples who experienced a PFS event before formal enrollment may be included separately as retrospective exploratory cases and will not be included in the primary analyses.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Histologically or cytologically confirmed
The diagnosis was confirmed by looking at a sample under a microscope: tissue from a biopsy or surgery (histology), or cells from a fluid or needle sample (cytology).
Your pathology report is the document that shows this.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Metastases
Cancer that has spread from where it began to other parts of the body. “Metastatic” cancer is cancer that has spread this way.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Line of therapy
A line of therapy is one course of treatment, which may combine several drugs. First-line is the first course given; second-line follows when that stops working or is not tolerated.
“Two prior lines” means two courses that count separately under the study’s rules — not simply two drugs. Ask the study team if you are unsure how yours are counted.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Life expectancy
The study doctor’s estimate of how long someone is likely to live. Criteria use it so that people can stay in the study long enough for it to answer its question.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients with advanced malignant phyllodes tumors of the breast who have distant metastases or are currently considered unsuitable for curative surgery and who are starting or receiving a current line of systemic therapy without a progression-free survival event at enrollment. Participants included in the primary longitudinal analysis must have a valid pretreatment blood sample obtained before the first dose of the current systemic treatment line. Participants will undergo longitudinal ctDNA monitoring, imaging assessment, and clinical follow-up during the current treatment line.
Progression-Free Survival According to Early ctDNA Status Transition Patterns
Circulating tumor DNA (ctDNA) detection status at pretreatment baseline (T0) and before cycle 3 (T2) defines four groups: negative at both visits, negative-to-positive, positive-to-negative, and positive at both visits. Progression-free survival (PFS), measured in months, is the time from initiation of the current systemic treatment line to first radiologically confirmed disease progression or death from any cause. Censoring follows the study protocol. Comparisons include participants with valid paired results who remain event-free at T2. T2 status is applied only after collection of the T2 sample, with appropriate risk-set handling to avoid immortal time bias. PFS will be summarized across the four groups; exploratory Cox regression will estimate hazard ratios and 95% confidence intervals if the number of events permits. Otherwise, descriptive survival results will be reported.
Time frame: From treatment-line initiation to radiologically confirmed progression, death, or censoring (up to 24 months); ctDNA at pretreatment baseline and before Cycle 3. Cycle length varies by regimen (usually 28 days; sometimes 21 days or other durations).
Progression-Free Survival According to Baseline ctDNA Detection Status
At pretreatment baseline (T0), circulating tumor DNA (ctDNA) detection status is classified as positive or negative according to prespecified assay criteria. Progression-free survival (PFS), measured in months, is the time from initiation of the current systemic treatment line to first radiologically confirmed disease progression or death from any cause; censoring follows the study protocol. PFS will be summarized by baseline ctDNA status. If the number of events permits, Cox regression will estimate the hazard ratio for ctDNA-positive versus ctDNA-negative participants with a 95% confidence interval.
Time frame: From initiation of the current systemic treatment line to the first radiologically confirmed disease progression, death from any cause, or censoring, assessed up to 24 months; baseline ctDNA status measured before the first treatment dose.
Progression-Free Survival According to Baseline ctDNA Concentration
Circulating tumor DNA (ctDNA) concentration is measured before treatment initiation (T0) in haploid genome equivalents per milliliter (hGE/mL). Baseline concentration is evaluated as a continuous predictor without a prespecified high/low cutoff. Reliably quantifiable positive concentrations will be log2-transformed for exploratory analysis. Progression-free survival (PFS), measured in months, is the time from initiation of the current systemic treatment line to first radiologically confirmed disease progression or death from any cause; censoring follows the protocol. A Cox model will estimate the hazard ratio and 95% confidence interval if data permit. Nondetectable or nonquantifiable values will be handled according to prespecified rules.
Time frame: From initiation of the current systemic treatment line to the first radiologically confirmed disease progression, death from any cause, or censoring, assessed up to 24 months; baseline ctDNA concentration measured before the first treatment dose.
Progression-Free Survival According to ctDNA Status Transitions Before Cycle 2
Circulating tumor DNA (ctDNA) detection status at pretreatment baseline (T0) and before cycle 2 (T1) defines four groups: negative at both visits, negative-to-positive, positive-to-negative, and positive at both visits. Progression-free survival (PFS), measured in months, is the time from initiation of the current systemic treatment line to first radiologically confirmed disease progression or death from any cause; censoring follows the protocol. Comparisons include participants with valid T0 and T1 results who remain event-free at T1. T1 status enters the analysis only after T1 sampling, with appropriate risk-set handling. PFS will be summarized by group; exploratory Cox regression will be performed if event counts permit.
Time frame: From treatment-line initiation to radiologically confirmed progression, death, or censoring (up to 24 months); ctDNA measured before the first dose and before cycle 2. Cycle length varies by regimen (usually 28 days; may be 21 days or other durations).
Progression-Free Survival According to the ctDNA Concentration Ratio at T1 Versus Baseline
Circulating tumor DNA (ctDNA) concentration is measured in haploid genome equivalents per milliliter (hGE/mL) at pretreatment baseline (T0) and before cycle 2 (T1). For participants with reliably quantifiable concentrations at both visits and T0 \> 0, the T1/T0 ratio is calculated as T1 concentration divided by T0 concentration; the ratio is unitless. Progression-free survival (PFS), measured in months, is the time from initiation of the current systemic treatment line to first radiologically confirmed disease progression or death from any cause; censoring follows the protocol. The ratio will be evaluated as a continuous predictor in exploratory Cox regression if data permit, using only risk time after T1 sampling. Invalid or nonquantifiable ratios will not be assigned arbitrary values.
Time frame: From treatment-line initiation to radiologically confirmed progression, death, or censoring (up to 24 months); ctDNA measured before the first dose and before cycle 2. Cycle length varies by regimen (usually 28 days; may be 21 days or other durations).
Progression-Free Survival According to the ctDNA Concentration Ratio at T2 Versus Baseline
Circulating tumor DNA (ctDNA) concentration is measured in haploid genome equivalents per milliliter (hGE/mL) at pretreatment baseline (T0) and before cycle 3 (T2). For participants with reliably quantifiable concentrations at both visits and T0 \> 0, the T2/T0 ratio is calculated as T2 concentration divided by T0 concentration; the ratio is unitless. Progression-free survival (PFS), measured in months, is the time from initiation of the current systemic treatment line to first radiologically confirmed disease progression or death from any cause; censoring follows the protocol. The ratio will be evaluated as a continuous predictor in exploratory Cox regression if data permit, using only risk time after T2 sampling. Invalid or nonquantifiable ratios will not be assigned arbitrary values.
Time frame: From treatment-line initiation to radiologically confirmed progression, death, or censoring (up to 24 months); ctDNA measured before the first dose and before cycle 3. Cycle length varies by regimen (usually 28 days; may be 21 days or other durations).
Progression-Free Survival According to Time-Updated ctDNA Detection Status at Subsequent Imaging Visits
Circulating tumor DNA (ctDNA) detection status (positive or negative) is assessed at routine CT/MRI imaging visits after T2 (T3 and later) during the current systemic treatment line. Progression-free survival (PFS), measured in months, is the time from treatment-line initiation to first radiologically confirmed disease progression or death from any cause; censoring follows the protocol. If sufficient data are available, a Cox model with ctDNA status as a time-varying covariate will estimate the hazard ratio for positive versus negative status and its 95% confidence interval. Status is updated at the actual sampling date; only previously collected samples are used to evaluate subsequent risk. If modeling is not feasible, findings will be descriptive.
Time frame: From treatment-line initiation to imaging-confirmed progression, death, or censoring (up to 24 months); ctDNA at routine CT/MRI visits following pre-cycle 3 sampling. Cycle length varies by regimen (usually 28 days; may be 21 days or other lengths).
Plan to share: Undecided
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Phyllodes Tumor
Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University →