Breast Phyllodes Tumors: Based on 20-year Real-world Data From China

June 4, 2026 updated by: Yan Nie, Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University

Clinical Features, Treatment Patterns, and Prognosis of Breast Phyllodes Tumors: A Multicenter Retrospective Study Based on 20-year Real-world Data From China.

Phyllodes tumor (PT) is a rare type of breast tumor made up of both connective tissue (stroma) and gland tissue (epithelium). It accounts for less than 1% of all breast tumors. The main symptom is a fast-growing, painless lump.

Based on its appearance under a microscope, the World Health Organization (WHO) classifies PT into three grades: benign (non-cancerous), borderline (intermediate), and malignant (cancerous). The chance of the tumor coming back after treatment (recurrence) is about 7%, 17%, and 25% for each grade, respectively. The average age when patients are diagnosed is between 36 and 55 years, and the typical tumor size ranges from about 4 to 11 cm. Malignant PT can spread to other parts of the body (metastasis) in up to 6% to 62% of cases, most often to the lungs or bones through the bloodstream.

Because PT is rare, large studies on its causes, diagnosis, treatment, and long-term outlook are very limited. PT can grow very quickly. Delaying diagnosis and treatment may allow the tumor to become so large that surgery is no longer an option. Standard imaging tests (ultrasound, mammogram, MRI) have limited ability to tell the difference between benign and malignant PT. Also, since these tumors are often large and vary from one area to another, a small needle biopsy may not show the whole picture. An accurate grade is usually only possible after the whole tumor is removed and examined by a pathologist.

PT does not respond well to radiation or chemotherapy. Therefore, the main treatment is complete surgical removal with clear margins. The role of newer therapies such as targeted therapy or immunotherapy is still being studied. Although the WHO grade gives some idea of how the patient might do, some benign PT can come back many times or even turn malignant, while some malignant PT stay stable for a long time. The current grading system does not fully explain why individual outcomes differ.

In recent years, most prediction models for PT have been built using Western patient data (for example, from the SEER database). These models have not been tested in Asian populations. They are usually based on small, single-center studies with dozens to a few hundred patients, and many have only been checked inside the same database without outside (external) validation. Most studies focus on symptoms, imaging findings, how to tell benign from malignant PT, or comparing different types of surgery. Few have looked closely at patterns of recurrence and metastasis, or risk factors for rare events like multiple recurrences, distant spread, or death.

To fill these gaps, we plan to conduct a large, multi-center, retrospective (looking back at past medical records) study across 8 top hospitals in China. We will use real-world data from about 3,500 patients with breast PT diagnosed between 2001 and 2023. The main goals are to describe the clinical and pathological features, treatment patterns, and long-term outcomes of Chinese PT patients. The main outcomes we will measure are local recurrence, distant metastasis, and overall survival. Secondary outcomes include disease characteristics and current treatment practices. This study aims to provide evidence from the Chinese population to help guide personalized treatment and future updates to clinical guidelines.

Study Overview

Status

Completed

Conditions

Study Type

Observational

Enrollment (Actual)

3500

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • China
    • Guangdong
      • Guangzhou, Guangdong, China, 510120
        • Sun Yat-sen Memorial Hospital, Sun Yat-sen University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

This study includes patients who underwent surgical resection for breast phyllodes tumor (PT) at one of eight tertiary hospitals in China between January 1, 2001, and December 31, 2023. All patients with a postoperative paraffin-embedded pathology diagnosis of benign, borderline, or malignant PT according to WHO criteria are included. Exclusion criteria are: (1) PT with uncertain behavior or unclassified grade; (2) history of prior malignancy (excluding breast cancer) with less than 5 years disease-free survival, or concurrent diseases that may affect endpoint assessment; (3) loss to follow-up or missing critical data (pathological grade, surgical procedure, or follow-outcome). A total of approximately 3,500 eligible patients from eight participating centers will be enrolled. All patients are of Chinese ethnicity.

Description

Inclusion Criteria:

  • Breast phyllodes tumors (benign, borderline, or malignant) based on postoperative paraffin pathology according to WHO criteria
  • Underwent surgical treatment
  • Complete or substantially complete clinical records, pathology reports, and follow-up data

Exclusion Criteria:

  • Phyllodes without histological grading
  • Hstory of other concomitant diseases that may affect the assessment of the study endpoint events
  • Patients lost to follow-up or with missing key data

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Benign Phyllodes Tumor
Borderline Phyllodes Tumor
Malignant Phyllodes Tumor

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Local Recurrence, LR
Time Frame: 3 year
Recurrence was defined as pathologically confirmed reoccurrence of phyllodes tumor in the ipsilateral breast, chest wall, or axillary lymph nodes after initial surgery, based on postoperative follow-up records (including outpatient visits, hospitalizations, and imaging findings) and pathology reports
3 year
Overall Survival, OS
Time Frame: 3 year
Overall survival was defined as the time interval from the date of initial surgery to the date of death from any cause, measured in months. Patients who remained alive were censored at the date of their last follow-up
3 year
Distant Metastasis, DM
Time Frame: 3 year
Extramammary organ metastasis (including but not limited to the lungs, liver, bones, and brain) confirmed by imaging studies (CT, PET-CT, bone scan, etc.) and/or pathological examination
3 year

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University

Collaborators

The First Affiliated Hospital of Guangzhou Medical University
First People's Hospital of Foshan
Peking University Shenzhen Hospital
Zhongshan People's Hospital, Guangdong, China
Foshan Women's and Children's Hospital
Sun Yat-Sen University Cancer Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 1, 2026

Primary Completion (Actual)

May 1, 2026

Study Completion (Actual)

May 20, 2026

Study Registration Dates

First Submitted

May 28, 2026

First Submitted That Met QC Criteria

June 4, 2026

First Posted (Actual)

June 9, 2026

Study Record Updates

Last Update Posted (Actual)

June 9, 2026

Last Update Submitted That Met QC Criteria

June 4, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • SYSEC2-2026-BA-790

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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