Recruiting

The Postoperative Radiotherapy in N1 Breast Cancer Patients

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.

ClinicalTrials.gov IDNCT05440149

PhasePHASE3

Enrollment1106

SponsorSeoul National University Hospital

Age19 Years

SexFEMALE

I'm interested View official listing

Conditions studied

Radiotherapy, Breast Cancer

About this study

Interventions

Radiation: No PMRT for mastectomy / No regional RT for BCS — * Regional RT includes high-tangent field, and can include undissected axilla. * The definition of high-tangent is that the upper margin of the radiotherapy field located within 2 cm of the humeral head to include axillary levels I and II. * Both hypofractionated and conventionally fractionated radiation therapy are allowed, and 3-dimensional or intensity modulated radiotherapy are allowed. The electron beam can also be used.
Radiation: PMRT for mastectomy / WBI + Regional RT for BCS — * Regional RT includes high-tangent field, and can include undissected axilla. * The definition of high-tangent is that the upper margin of the radiotherapy field located within 2 cm of the humeral head to include axillary levels I and II. * Both hypofractionated and conventionally fractionated radiation therapy are allowed, and 3-dimensional or intensity modulated radiotherapy are allowed. The electron beam can also be used.

Primary outcomes

Disease-Free Survival (7-Year)

Eligibility information

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 locations

Seoul National University Hospital, Seoul, Jongro-gu 03080 South Korea

Before you participate: Varda Clinical is an independent discovery tool, not the study sponsor or a medical provider. Eligibility can only be determined by the official study team. Discuss potential risks and benefits with a qualified healthcare professional.

Source: ClinicalTrials.gov. Record last refreshed by Varda Clinical: 2026-09-27.