Comparing radiotherapy and low-dose tamoxifen after breast surgery for low-risk ductal carcinoma in situ

Radiotherapy Versus Low-Dose Tamoxifen Following Breast Conserving Surgery for Low-Risk and Estrogen Receptor-Positive Ductal Carcinoma in Situ of Breast: an International Open-label Randomized Non-inferiority Trial

This study tests whether low-dose tamoxifen can be as effective as radiotherapy for women over 40 with low-risk ductal carcinoma in situ after breast surgery.

Quick facts

• Phase: Phase 3
• Study type: Interventional
• Enrollment: 810 (estimated)
• Ages: 40 Years and up
• Sex: Female
• Sponsor: National Taiwan University Hospital (Academic / other)
• Drugs / interventions: Radiation
• Locations: 1 site (Taipei)
• Trial ID: NCT04046159 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to evaluate the effectiveness of low-dose tamoxifen versus whole breast radiotherapy following breast conserving surgery in women diagnosed with low-risk ductal carcinoma in situ (DCIS). The study focuses on patients aged 40 and older with specific pathological characteristics, including unicentric lesions and estrogen receptor-positive status. By analyzing recurrence rates, the trial seeks to determine if radiotherapy can be safely omitted in certain low-risk patients. The findings could help refine treatment approaches for DCIS, potentially reducing unnecessary interventions.

Who should consider this trial

Good fit: Ideal candidates for this study are women aged 40 and older with newly diagnosed, low-risk, estrogen receptor-positive ductal carcinoma in situ.

Not a fit: Patients with known BRCA mutations or those under 40 years of age may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could provide a less invasive treatment option for patients with low-risk DCIS, reducing the need for radiotherapy.

How similar studies have performed: Previous studies have shown promising results in similar patient populations, indicating that this approach may be viable.

Eligibility criteria

Inclusion Criteria:

1. Women
2. New histologically diagnosed breast ductal carcinoma in situ (DCIS).
3. Age ≥ 40 years
4. Low risks of BRCA (breast cancer)1 and BRCA2: Manchester Score \< 10
5. The DCIS must be detected by mammogram and must be unicentric, and no-mass lesion.
6. Status post breast conserving surgery
7. Pathological characteristics (all characteristics) 7.1 Lesions ≤ 2.5 cm in greatest dimension on pathologic specimen (use the largest measured size from the pathology report to obtain the required measurement of ≤ 2.5 cm).

   7.2 Must be classified as low or intermediate nuclear grade DCIS but without comedo necrosis according to Pathologic Guidelines (section 9.2.2) 7.3 Margins as assessed by the ink method will be 3 mm or greater. 7.4 Must be estrogen receptor (ER)-positive DCIS, ER percentage must be ≥10%
8. Clinically node negative.

Exclusion Criteria:

1. Known BRCA1 or BRCA2 mutation
2. Age \< 40 years
3. Women whose DCIS is palpable at the time of diagnosis, or multi-centric (mammography), or mass (mammography), or who have bloody nipple discharge.
4. Pathological characteristics 4.1 Lesions measuring greater than 2.5 cm in greatest dimension on pathologic specimen.

   4.2.High-grade lesions or low to intermediate grade with comedo necrosis as classified by the Guidelines.

   4.3. Margins as assessed by the ink method will be less than 3 mm. 4.4. ER-negative DCIS or ER-positive percentage \< 10% in tumor cells
5. Post-mastectomy patients
6. Prior diagnosis of neoplasm within 5 years, except cervical intraepithelial neoplasia type 1 (CIN1) or localized non-melanomatous skin cancer.
7. Evidence of clinically significant cardiac disease, as defined by cardiac disease (New York Cardiac disease grade II), history of myocardial infarction, cerebral stroke, unstable arrhythmia, and unstable angina pectoris within 12 months before study entry.
8. Pregnant or lactating status.

Where this trial is running

Taipei

• National Taiwan University Hospital — Taipei, Taiwan (Recruiting)

Study contacts

• Principal investigator: Chiun-Sheng Huang, MD, PhD, MPH — Department of Surgery, National Taiwan University Hospital
• Study coordinator: Chiun-Sheng Huang, MD, PhD, MPH

Conditions Breast Ductal Carcinoma in Situ