The Postoperative Radiotherapy in N1 Breast Cancer Patients

Phase 3

Recruiting

• Conditions: Breast Cancer; Radiotherapy
• Interventions: Radiation: No PMRT for mastectomy / No regional RT for BCS; Radiation: PMRT for mastectomy / WBI + Regional RT for BCS

• Registration Number: NCT05440149
• Lead Sponsor: Seoul National University Hospital

Brief Summary

This study is a multicenter, randomized, phase 3 clinical trial in patients with breast cancer, randomizing radiotherapy group (postmastectomy radiation therapy (PMRT)/whole breast irradiation plus regional radiotherapy (WBI+regional RT) versus and no PMRT/WBI alone group. This is a non-inferiority study aiming that there is no significant difference in the 7-year disease-free survival rate between the two groups.

Detailed Description

1:1 randomization to the control group and experimental group, stratified by the type of surgery (breast-conserving surgery (BCS) versus mastectomy) and the type of histologic type (triple negative breast cancer (TNBC) versus non-TNBC)

The control group:

* If patients received BCS, WBI+Regional RT

* If patients received mastectomy, PMRT

The experimental group:

* If patients received breast conserving surgery, WBI alone

* If patients received mastectomy, No PMRT

Study Timeline

• Study First Submitted: 2022-06-27
• Study First Submitted QC: 2022-06-27
• Study First Posted: 2022-06-30
• Study Start: 2022-08-01
• Status Verified: 2024-11
• Last Update Submitted: 2024-11-26
• Last Update Posted: 2024-11-28
• Primary Completion: 2026-12-31
• Study Completion: 2033-12-31

Recruitment & Eligibility

• Status: RECRUITING
• Sex: Female
• Target Recruitment: 1106

Inclusion Criteria

• Patients aged 19 years or older.

• A female patient who underwent breast-conserving surgery or mastectomy for invasive breast cancer.

• Patient with stage pN1 after surgery on histopathologic examination.

  • However, if mastectomy was performed, 5 or more nodes should be resected in the case of 1 positive node, and axillary lymph node dissection (ALND) should be performed in case of 2 or 3 positive nodes.

• Patients undergoing or planning to undergo hormone therapy in the case of hormone receptor positive.

• Patients who have received or are expected to undergo targeted therapy in the case of human epidermal growth factor receptor(HER)-2 positive.

• Patients with Eastern Cooperative Oncology Group (ECOG) Scale 0-2.

• Patients who agreed to participate in the study.

Exclusion Criteria

• Patients who have received prior [neoadjuvant] chemotherapy.
• Patients receiving radiation therapy for salvage or palliative purposes.
• Patients with stage T4.
• Patients with ipsilateral supraclavicular and internal mammary lymph node metastases or distant metastases.
• Male breast cancer patient.
• Patients who have previously received radiation therapy to the ipsilateral breast or supraclavicular region.
• Patients having a history of cancer other than thyroid cancer, cervical carcinoma in situ, or skin cancer.
• Patients diagnosed with ductal breast carcinoma in situ, lobular carcinoma in situ, phyllodes, metaplastic cancer, or benign tumors based on histological diagnosis.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
The Experimental group	No PMRT for mastectomy / No regional RT for BCS	* If patients received mastectomy, No PMRT should be performed. * If patients received BCS, WBI alone should be performed.
The Control group	PMRT for mastectomy / WBI + Regional RT for BCS	* If patients received mastectomy, post-mastectomy radiation therapy (PMRT) should be performed. * If patients received breast conserving surgery (BCS), whole breast irradiation (WBI) + Regional radiotherapy (RT) should be performed.

Primary Outcome Measures

Name	Time	Method
Disease-Free Survival	7-Year	Time from randomization to local recurrence, regional recurrence, distant metastases, or breast cancer-related death.

Secondary Outcome Measures

Name	Time	Method
Locoregional-Recurrence Free Survival	7-Year	Time from randomization to recurrence of tumors in the ipsilateral chest wall, breast or regional lymph nodes (ipsilateral axillary/internal mammary/supraclavicular lymph nodes) or breast cancer-related death.; \*\* Recurrence should be confirmed by histological diagnosis, but local recurrence can be diagnosed by clinical examination only when regional/remote or distant metastases already exist.
Distant Metastases Free Survival	7-Year	Time from randomization to the development of distant metastases or breast cancer-related death.
Overall Survival	7-Year	Time from randomization to the death due to any cause.

Trial Locations

Locations (1)

Seoul National University Hospital; 🇰🇷 Seoul, Jongro-gu, Korea, Republic of