Avoiding Surgery in Estrogen Receptor Positive Atypical Ductal Hyperplasia and In-situ Carcinoma Treated With Endocrine Treatment Trial (ASAIN)

This study aims to evaluate the 5-year invasive ipsilateral breast cancer incidence rate in patients with hormone-receptor positive, HER-2 negative atypical ductal hyperplasia or in-situ carcimona who omitted surgery and received endocrine therapy.

Study Overview

• Status: Not yet recruiting
• Conditions: Ductal Carcinoma in Situ of the Breast
• Intervention / Treatment: Procedure: Avoiding surgery

• Study Type: Interventional
• Enrollment (Estimated): 340
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jeong Eon Lee, MD, PhD; Phone Number: +82-10-9933-0260; Email: paojlus@hanmail.net

Study Locations

• South Korea
  • Seoul, South Korea
    • Samsung Medical Center
    • Contact: Jeong Eon Lee, MD, PhD; Phone Number: +82-10-9933-0260; Email: paojlus@hanmail.net

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

1. Inclusion criteria:

1. Female patients aged ≥35 years.
2. Diagnosed with atypical ductal hyperplasia (ADH), ductal carcinoma in situ (DCIS), or lobular carcinoma in situ (LCIS) on core-needle biopsy, vacuum-assisted biopsy, or excisional biopsy.
3. Immunohistochemistry (IHC) performed on biopsy specimens confirming estrogen receptor (ER), progesterone receptor (PR), and HER2 status; eligible only if the ER Allred total score is ≥7 and HER2 status is negative.
4. All low- and intermediate-grade nuclear grades included; for high-grade lesions, only patients with a Ki-67 index ≤20% are eligible.
5. Lesion not definitely palpable on physical examination at diagnosis.
6. No prior breast surgery for ipsilateral or contralateral breast cancer, and no synchronous contralateral breast cancer.
7. Not diagnosed with pregnancy-associated breast cancer or breast cancer detected during lactation.
8. Negative serum or urine β-hCG prior to enrollment.
9. Provided written informed consent to participate in the study.

2. Exclusion criteria:

1. Pregnant patients.
2. Patients with clinically significant psychiatric disorders (e.g., major depressive disorder) or those currently receiving psychiatric or antipsychotic medications.
3. Concomitant diagnosis of invasive breast cancer.
4. Evidence of axillary lymph node metastasis.
5. Carriers of BRCA1/2 mutations.
6. Male patients.
7. History of diagnosis or treatment for breast cancer.
8. Presence or history of other malignancies besides breast cancer.
9. Concomitant diagnosis of pleomorphic LCIS.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Active monitoring arm; Active monitoring with endocrine therapy in hormone-receptor positive, HER-2 negative DCIS, LCIS, ADH without surgery	Procedure: Avoiding surgery; Avoiding surgery in hormone-receptor positive atypical ductal hyperplasia and in-situ carcinoma treated with endocrine treatment

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
5 year ipsilateral breast cancer incidence rate	This study aims to evaluate the 5-year invasive ipsilateral breast cancer incidence rate in patients with hormone-receptor positive, HER-2 negative atypical ductal hyperplasia or in-situ carcimona who omitted surgery and received endocrine therapy.	5 years after the last patient enrollment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Adjuvant chemotherapy rate	5 year adjuvant chemotherapy rate	5 years after the last patient enrollment
invasive CBC rate	5 year invasive contralateral breast cancer rate	5 years after the last patient enrollment
OS	5 year overall survival	5 years after the last patient enrollment
BCSS	5 year breast cancer specific survival	5 years after the last patient enrollment
Change in health-related quality of life assessed by EORTC QLQ-C30	HRQoL will be evaluated using the EORTC QLQ-C30. Scores range from 0-100. Higher functional/global health scores indicate better QoL, while higher symptom scores indicate greater symptom burden.	At baseline, at 2 years, and at 5 years after the last patient enrollment
Change in breast cancer-specific quality of life assessed by EORTC QLQ-BR23	Breast cancer-specific QoL will be assessed using the EORTC QLQ-BR23. Scores range from 0-100. Higher functional scores indicate better QoL; higher symptom scores indicate worse symptom burden.	At baseline, at 2 years, and at 5 years after the last patient enrollment

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prognostic differences in invasive breast cancer progression according to age and type of endocrine therapy	Invasive breast cancer progression will be evaluated according to age at diagnosis and type of endocrine therapy. The proportion of participants who develop histologically confirmed invasive breast cancer during follow-up will be compared across subgroups defined by age and endocrine therapy regimen (tamoxifen, aromatase inhibitor, or combination with ovarian function suppression).	5 years after the last patient enrollment
Adverse events associated with endocrine therapy and ovarian function suppression	Incidence and severity of adverse events related to endocrine therapy and/or ovarian function suppression, graded according to CTCAE criteria.	From initiation of endocrine therapy to treatment discontinuation or last follow-up (up to 5 years after enrollment)
Direct medical cost of active monitoring compared with standard therapy	Mean total direct medical cost (USD) incurred during 5-year follow-up will be compared between the active monitoring protocol and standard surgical management based on institutional billing data.	5 years after the last patient enrollment
Incremental cost-effectiveness ratio (ICER) of active monitoring compared with standard therapy	Cost-effectiveness will be evaluated by the incremental cost-effectiveness ratio (ICER), calculated as cost per quality-adjusted life-year (QALY) gained for active monitoring versus standard therapy.	5 years after last patient enrollment.
Change in circulating tumor DNA (ctDNA) detectability from baseline to surgery among participants who undergo surgery for invasive progression	Paired assessment of ctDNA detectability (present/absent) at baseline (diagnosis) and at the time of surgery among participants who progress to invasive breast cancer. Peripheral blood (20 mL) is collected at both time points.	Baseline and at time of surgery
Longitudinal detectability of circulating tumor DNA (ctDNA) at annual follow-up compared with baseline	Assessment of ctDNA detectability (present/absent) at baseline and at annual follow-up visits in all enrolled participants. Peripheral blood (20 mL) is collected at each time point.	Baseline (Day 1) and annually through study completion (up to 5 years)

Collaborators and Investigators

• Sponsor: Jeong Eon Lee
• Investigators: Principal Investigator: Jeong Eon Lee, MD, PhD, Samsung Medical Center

Study record dates

Study Major Dates

• Study Start (Estimated): December 1, 2025
• Primary Completion (Estimated): December 31, 2032
• Study Completion (Estimated): December 31, 2032

Study Registration Dates

• First Submitted: August 20, 2025
• First Submitted That Met QC Criteria: November 17, 2025
• First Posted (Actual): November 24, 2025

Study Record Updates

• Last Update Posted (Actual): November 24, 2025
• Last Update Submitted That Met QC Criteria: November 17, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: ASAIN
• Additional Relevant MeSH Terms: Breast Carcinoma In Situ; Neoplasms; Neoplasms by Histologic Type; Neoplasms, Glandular and Epithelial; Adenocarcinoma; Carcinoma; Neoplasms, Ductal, Lobular, and Medullary; Carcinoma in Situ; Carcinoma, Intraductal, Noninfiltrating
• Other Study ID Numbers: SMC 2025-02-036

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No