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

Phase 2RecruitingNCT07762924

Fudan University234 enrolled

Overview

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).

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

234

Conditions

Ductal Carcinoma In Situ, DCIS

Interventions

Eligibility

Sex: FEMALEMax age: 40 Years

Medical Language ↔ Plain English

Inclusion Criteria: 1. Female patients aged \<40 years； 2. Histologically confirmed low- or intermediate-grade ductal carcinoma in situ (DCIS) without invasive carcinoma, including incidental DCIS identified within benign breast lesions； 3. Tumor size ≤1 cm on final pathology； 4. Negative surgical margins ≥3 mm, including margins obtained after re-excision； 5. Unifocal lesion； 6. Absence of comedo necrosis； 7. Screen-detected disease without bloody nipple discharge or palpable mass； 8. Clinically node-negative disease； 9. Central pathology review by the participating institution required； 10. Ability to understand and willingness to sign written informed consent. Exclusion Criteria: 1. Known BRCA1, BRCA2, or TP53 germline mutation carriers (genetic testing not mandatory)； 2. Bilateral breast cancer or prior contralateral breast cancer； 3. Severe uncontrolled comorbidities, including significant cardiac, pulmonary, hepatic, renal, hematologic, or psychiatric disorders； 4. History of other malignancies, including thyroid cancer, except adequately treated basal cell carcinoma of the skin or cervical carcinoma in situ； 5. Pregnant or breastfeeding patients； 6. Estimated life expectancy ≤5 years； 7. Poor compliance or inability to adhere to study follow-up requirements.

Outcomes

Primary Outcomes

Ipsilateral Breast Tumor Recurrence (IBTR)

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

Time frame: 5 years

Secondary Outcomes

Local-Regional Recurrence (LRR)

Defined as recurrence in the ipsilateral breast, chest wall, supraclavicular region, axilla, or internal mammary region.

Time frame: 5 years

Breast Cancer-Specific Survival (BCSS)

Defined as time from study enrollment to death due to breast cancer.

Time frame: 5 years

Overall Survival (OS)

Defined as time from study enrollment to death from any cause.

Time frame: 5 years

Distant Metastasis-Free Survival (DMFS)

Distant Metastasis defined as recurrence outside local-regional sites.

Time frame: 5 years

Contralateral Breast Cancer Events

Defined as participants diagnosed with a new primary breast cancer in the contralateral breast. Diagnosis will be confirmed by pathological examination.

Time frame: 5 years

Mastectomy-Free Survival

Defined as participants who are alive and have not undergone mastectomy of the treated breast after initiation of study treatment.

Time frame: 5 years

Second Primary Malignancies

Defined as participants diagnosed with a new primary malignancy, excluding recurrence or metastasis of the index breast cancer.

Time frame: 5 years

Quality-of-Life Assessed by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30)

Global health quality of life is assessed using the EORTC QLQ-C30. Scores are transformed to a 0-100 scale, with higher scores indicating better global health status and quality of life. Change from baseline will be evaluated during follow-up.

Time frame: 5 years

Quality-of-Life Assessed by the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Breast Cancer Module 23 (EORTC QLQ-BR23)

Breast cancer-specific symptom burden is assessed using the EORTC QLQ-BR23. Scores are transformed to a 0-100 scale. Change from baseline will be evaluated during follow-up.

Time frame: 5 years

Anxiety Assessment

Change from baseline in anxiety symptoms assessed using a validated patient-reported anxiety assessment instrument.

Time frame: 5 years

Patient-Reported Outcomes

Change from Baseline in Patient-reported Treatment-related Symptoms Assessed by PRO-CTCAE.

Time frame: 5 years

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

Overview

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

Primary Outcomes

Secondary Outcomes

Central Contacts