Omission of Adjuvant Radiotherapy in Young Low-Risk Ductal Carcinoma In Situ Following Breast-Conserving Surgery

NCT07762924 | Recruiting Phase 2

• 1 other identifier: FDRT-BC030
• Study Type: interventional
• Target: 234
• Locations: 1 country
• Sites: 1

Brief Summary

This is a single-center, prospective phase II clinical study designed to evaluate whether omission of postoperative radiotherapy is clinically acceptable in young patients with low-risk ductal carcinoma in situ (DCIS) following breast-conserving surgery. Eligible patients include women younger than 40 years with low- or intermediate-grade DCIS, tumor size ≤1 cm, negative surgical margins ≥3 mm, absence of comedo necrosis, and unifocal screen-detected disease. Patients in the radiotherapy omission cohort will undergo close surveillance after surgery, with endocrine therapy permitted according to physician discretion. The primary endpoint is 5-year ipsilateral breast tumor recurrence (IBTR).

Conditions

Ductal Carcinoma In Situ, DCIS

Outcome Measures

Primary Outcomes (1)

• Ipsilateral Breast Tumor Recurrence (IBTR)

  Defined as recurrence of invasive carcinoma or DCIS in the ipsilateral breast.

  5 years

Secondary Outcomes (11)

• Local-Regional Recurrence (LRR)

  5 years

• Breast Cancer-Specific Survival (BCSS)

  5 years

• Overall Survival (OS)

  5 years

• Distant Metastasis-Free Survival (DMFS)

  5 years

• Contralateral Breast Cancer Events

  5 years

Other Outcomes (2)

• Tumor-Infiltrating CD8-Positive T-Cell Density

  Baseline

• Tumor PD-L1 Expression

  Baseline

Study Arms (1)

Radiotherapy Omission

EXPERIMENTAL

Patients will undergo observation alone after breast-conserving surgery with regular clinical and imaging follow-up. Endocrine therapy is permitted according to institutional practice.

Other: Observation; Drug: Endocrine Therapy (Optional)

Interventions

Observation OTHER

No postoperative radiotherapy will be administered. Patients will receive close surveillance after surgery.

Radiotherapy Omission

Endocrine Therapy (Optional) DRUG

Adjuvant endocrine therapy may be administered according to physician discretion and patient preference.

Radiotherapy Omission

Eligibility Criteria

• Age: Up to 40 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Female patients aged \<40 years；
• Histologically confirmed low- or intermediate-grade ductal carcinoma in situ (DCIS) without invasive carcinoma, including incidental DCIS identified within benign breast lesions；
• Tumor size ≤1 cm on final pathology；
• Negative surgical margins ≥3 mm, including margins obtained after re-excision；
• Unifocal lesion；
• Absence of comedo necrosis；
• Screen-detected disease without bloody nipple discharge or palpable mass；
• Clinically node-negative disease；
• Central pathology review by the participating institution required；
• Ability to understand and willingness to sign written informed consent.

You may not qualify if:

• Known BRCA1, BRCA2, or TP53 germline mutation carriers (genetic testing not mandatory)；
• Bilateral breast cancer or prior contralateral breast cancer；
• Severe uncontrolled comorbidities, including significant cardiac, pulmonary, hepatic, renal, hematologic, or psychiatric disorders；
• History of other malignancies, including thyroid cancer, except adequately treated basal cell carcinoma of the skin or cervical carcinoma in situ；
• Pregnant or breastfeeding patients；
• Estimated life expectancy ≤5 years；
• Poor compliance or inability to adhere to study follow-up requirements.

Sponsors & Collaborators

• Fudan University: lead

Study Sites (1)

Fudan University Shanghai Cancer Center

Shanghai, 200032, China

RECRUITING

MeSH Terms

Conditions

Carcinoma, Intraductal, Noninfiltrating

Interventions

Observation

Condition Hierarchy (Ancestors)

Adenocarcinoma; Carcinoma; Neoplasms, Glandular and Epithelial; Neoplasms by Histologic Type; Neoplasms; Breast Carcinoma In Situ; Carcinoma in Situ; Neoplasms, Ductal, Lobular, and Medullary

Intervention Hierarchy (Ancestors)

Methods; Investigative Techniques

Central Study Contacts

Xiaoli Yu

CONTACT

+86-021-64175590; xiaoliyu@fudan.edu.cn

Jin Meng

CONTACT

+86 18121299532; jinmeng@fudan.edu.cn

Study Design

• Study Type: interventional
• Phase: phase 2
• Allocation: NA
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor

Study Record Dates

• First Submitted: June 23, 2026
• First Posted: August 13, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): February 1, 2032
• Study Completion (Estimated): February 1, 2037
• Last Updated: August 13, 2026

Record last verified: 2026-06

Locations

CN (1)