Comparing partial breast irradiation to no irradiation for early breast cancer in women

The DBCG RT Natural Trial: Partial Breast Versus no Irradiation for Women >=60 Years Operated With Breast Conservation for an Early Breast Cancer: a Clinically Controlled Randomized Phase III Trial

NA · Danish Breast Cancer Cooperative Group · NCT03646955

This study is testing if women with early breast cancer can skip radiation treatment after surgery without increasing their chances of the cancer coming back.

Quick facts

PhaseNA
Study typeInterventional
Enrollment926 (estimated)
Ages60 Years and up
SexFemale
SponsorDanish Breast Cancer Cooperative Group (other)
Drugs / interventionsradiation
Locations17 sites (Santiago and 16 other locations)
Trial IDNCT03646955 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to identify low-risk breast cancer patients who can safely omit adjuvant partial breast irradiation (PBI) after breast-conserving surgery. The study will evaluate the effectiveness of avoiding radiation therapy in selected patients who are unlikely to benefit from it, thereby reducing the risk of side effects associated with radiation. By analyzing patient characteristics and outcomes, the trial seeks to establish criteria for determining which patients can forgo radiation without significantly increasing their risk of local cancer recurrence. The approach is based on previous findings that suggest low local recurrence rates in similar patient populations.

Who should consider this trial

Good fit: Ideal candidates for this study are women aged 60 and older with early-stage, low-risk breast cancer characteristics.

Not a fit: Patients with multifocal or multicentric invasive carcinoma, grade 3 malignancy, or previous breast cancer may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could help reduce unnecessary radiation treatment for certain breast cancer patients, minimizing side effects and improving quality of life.

How similar studies have performed: Previous studies, such as the DBCG RT PBI trial and the UK IMPORT LOW trial, have shown promising results with similar approaches in low-risk breast cancer patients.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Female patient \>=60 years

Primary tumour characteristics by conventional histopathology

* unilateral and unifocal non-lobular histology grade 1-2
* maximum microscopic size \<=20mm
* node negative determined by sentinel node or axillary lymph node dissection
* estrogen receptor \>=10% positive
* HER2 negative (by IHC and/or in situ hybridization)
* resection margin \>=2 mm for invasive carcinoma and any ductal carcinoma in situ associated with the cancer

Surgical type is breast conservation

Performance status ECOG 0-2

No evidence of distant metastasis

Exclusion Criteria:

* multifocal or multicentric invasive carcinoma or ductal carcinoma in situ
* evidence of clinical or pathological T4 breast cancer
* grade 3 malignancy
* previous breast cancer or DCIS irrespective of disease-free interval
* previous radiation therapy to the breast or thorax,
* previous neoplasm within 5 years except carcinoma in situ of the cervix, endometrium or coli, melanoma in situ.
* comorbidity precluding the patient from radiation therapy (e.g. cardiovascular or pulmonary disease, scleroderma, systemic lupus erythematosus).
* mental/psychiatric disorder which precludes the patient from understanding the randomization and the follow up.
* documented hereditary breast cancer or with high genetic risk of breast cancer
* life expectancy \<10 years

Where this trial is running

Santiago and 16 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Local Neoplasm Recurrence, Distantly Metastatic Malignant Neoplasm, Death, Fibrosis Breast, Depigmentation/Hyperpigmentation of Skin, Telangiectasia, Scar, Pain

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.