Omitting radiotherapy for breast cancer patients with complete response to treatment

DESCARTES: De-ESCAlation of RadioTherapy in Patients With Pathologic Complete rESponse to Neoadjuvant Systemic Therapy

Not applicable Interventional The Netherlands Cancer Institute · NCT05416164

This study is testing if women with early-stage breast cancer who have no signs of the disease after treatment can skip radiation therapy safely.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment595 (estimated)
Ages18 Years and up
SexFemale
SponsorThe Netherlands Cancer Institute Academic / other
Locations1 site (Amsterdam, North Holland)
Trial IDNCT05416164 on ClinicalTrials.gov

What this trial studies

This study evaluates the safety of omitting radiotherapy in breast cancer patients with T1-2N0 tumors who achieve a pathologic complete response after receiving neoadjuvant systemic therapy and undergoing breast-conserving surgery. The research focuses on a growing population of women diagnosed with breast cancer who are treated with neoadjuvant systemic therapy, where a significant percentage may achieve a complete response. By investigating the potential to forgo radiotherapy, the study aims to reduce treatment-related morbidity while maintaining low local recurrence rates in this specific patient group.

Who should consider this trial

Good fit: Ideal candidates are women aged 18 and older with node-negative breast tumors less than 5 cm who have achieved a pathologic complete response after neoadjuvant systemic therapy.

Not a fit: Patients with extensive DCIS or those who do not achieve a pathologic complete response may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could reduce unnecessary radiotherapy exposure and its associated side effects for certain breast cancer patients.

How similar studies have performed: Other studies have explored similar approaches, but this specific investigation into omitting radiotherapy for this patient group is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Women, aged ≥ 18 years
* Invasive HR positive/Her2 negative, Her2+ (ER/PR +/-) or TN breast cancer
* Concurrent DCIS in pre-NST biopsy is allowed if there is no suspicion of extensive component i.e. absence of non-mass enhancement on pre-NST MRI, contrast-enhanced mammography or breast-specific gamma imaging and/or absence of calcifications on pre-NST mammography
* Primary tumour (T) clinical stage cT1-2
* Unifocal disease; confirmed by pre-NST MRI, contrast-enhanced mammography or breast-specific gamma imaging
* Clinical nodal stage 0; absence of lymph node metastases should be confirmed by ultrasound or FDG-PET/CT
* Neoadjuvant systemic treatment (NST)
* Marker placed in breast tumour prior to NST
* Breast conserving surgery performed, i.e. no mastectomy
* Sentinel node biopsy performed before or after NST
* Pathologic complete response in breast and lymph nodes, i.e. no residual tumour cells or DCIS detected
* Written informed consent

Exclusion Criteria:

* Primary tumour (T) clinical stage cT3-4
* Pre- or post-NST diagnosis of nodal disease including isolated tumour cells
* Patients without axillary ultrasound or FDG-PET/CT pre-NST
* History of breast cancer or DCIS
* Synchronous contralateral breast cancer or DCIS
* Synchronous M1 disease
* Carrier of gene mutation associated with increased risk of breast cancer, i.e. BRCA1, BRCA2, CHEK2, TP53 or PALB-2

Where this trial is running

Amsterdam, North Holland

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.
Conditions Breast CancerNeoadjuvant ChemotherapyBreast cancerComplete responseRadiotherapy
Last reviewed 2026-06-13 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.