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Recruiting NCT05505357

NCT05505357 Omission of Breast Surgery for Breast Cancer Patients With pCR on MRI and Vacuum-assisted Biopsy After NST (OPTIMIST)

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Clinical Trial Summary
NCT ID NCT05505357
Status Recruiting
Phase
Sponsor Seoul National University Hospital
Condition Breast Cancer Invasive
Study Type INTERVENTIONAL
Enrollment 533 participants
Start Date 2022-09-22
Primary Completion 2026-06

Eligibility & Interventions

Sex Female only
Min Age 20 Years
Max Age N/A
Study Type INTERVENTIONAL
Interventions
Breast surgery omission

Eligibility Fast-Check

Enter your details for a quick preliminary check. This does not replace medical advice.

What to Expect as a Participant

You will actively receive the study intervention — which may be a drug, biologic, device, or procedure.

This trial targets 533 participants in total. It began in 2022-09-22 with a primary completion date of 2026-06.

⚠ This information is for research awareness only. Always consult your physician before joining any clinical trial. Participation is voluntary and you may withdraw at any time.

Brief Summary

A prospective, multicenter, single-arm non-inferiority trial to demonstrate that breast cancer patients who are predicted to have a pathologic complete response on MRI and vacuum-assisted biopsy after neoadjuvant systemic therapy, and are omitted breast surgery have a non-inferior 5-year disease-free survival compared to those who had received breast surgery.

Eligibility Criteria

Inclusion Criteria: * Sex: female * Age: 20 years and older * Patients with no clinical/radiologic distant metastasis * Tumor type: Invasive ductal carcinoma * Tumor subtype: HER2 positive(including luminal B type, triple negative * Extent of disease: initial tumor size ≤ 5cm, cN0-2 * Patients with measurable tumor size * Patients who are expected to achieve pCR after neoadjuvant chemotherapy (MRI size ≤ 1.0 cm AND L-to-B SER ≤ 1.6) * Patients with clip inserted to the primary tumor site before or during neoadjuvant chemotherapy * Patients with informed consent who are competent to make a voluntary decision Exclusion Criteria: * Multifocal lesion (≥2) * Extent of residual microcalcification after neoadjuvant chemotherapy \> 2cm * Bilateral breast cancer or inflammatory breast cancer * Contraindication to radiotherapy * History of previous contralateral breast cancer * Breast cancer patients with distant metastasis * Allergic history to MRI contrast * Male breast cancer * Patients incapable of giving informed consent owing to poor general conditions * Patients with BRCA mutation * Patients willing to receive breast surgery * Patients with a history of cancer diagnosis within 5 years (However, skin cancer other than melanoma and breast carcinoma in situ other than ductal carcinoma in situ can be registered even if 5 years have not passed since the diagnosis)

Contact & Investigator

Central Contact

Han-Byoel Lee

✉ hblee80@gmail.com

📞 +82-2-2072-3447

Principal Investigator

Han-Byoel Lee

PRINCIPAL INVESTIGATOR

Seoul National University Hospital

Frequently Asked Questions

Who can join the NCT05505357 clinical trial?

This trial is open to female participants only, aged 20 Years or older, studying Breast Cancer Invasive. Full inclusion and exclusion criteria are listed in the Eligibility Criteria section. Always confirm your eligibility with the research team before applying.

Is NCT05505357 currently recruiting?

Yes, NCT05505357 is actively recruiting participants. Contact the research team at hblee80@gmail.com for enrollment information.

Where is the NCT05505357 trial being conducted?

This trial is being conducted at Seoul, South Korea.

Who is sponsoring the NCT05505357 clinical trial?

NCT05505357 is sponsored by Seoul National University Hospital. The principal investigator is Han-Byoel Lee at Seoul National University Hospital. The trial plans to enroll 533 participants.

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ClinicalMetric — Independent clinical trial intelligence platform. Not affiliated with NIH, ClinicalTrials.gov, the U.S. FDA, or any pharmaceutical company, hospital, or clinical research organization. Trial data is sourced from ClinicalTrials.gov for informational purposes only and does not constitute medical advice. Do not make any treatment, enrollment, or health decisions based solely on information found here — always consult a qualified healthcare professional. Full Disclaimer  ·  Last Reviewed: July 2026  ·  Data Methodology