Title and Protocol ID	Study Details and Status
Surgical treatment/Active Surveillance
A Randomized Phase 2 Study Comparing Surgical Excision Versus Neoadjuvant Radiotherapy Followed by a Delayed Surgical Excision of Ductal Carcinoma In Situ (NORDIS)-NCT03909282	Phase 2 trial surgical excision vs. neoadjuvant radiotherapy + a delayed surgical excision of DCIS (NORDIS; estimated time of completion 2025).
Impact of Neoadjuvant Hormonal Therapy on the Surgical Management of Extensive Ductal Carcinomas in Situ (NORNE001)- NCT04666961	Phase 2 trial investigating neoadjuvant tamoxifen or anastrozole and a delayed surgical excision of DCIS (estimated time of completion 2024).
Comparing an Operation to Monitoring, With or Without Endocrine Therapy (COMET) Trial For Low Risk DCIS--NCT02926911	Phase 3 prospective randomized trial comparing surgery +/− radiation with the choice of endocrine therapy and active monitoring with the choice of endocrine therapy (estimated time of completion 2028).
Management of Low-Risk (Grade I and II) DCIS (LORD)- NCT02492607	Nonrandomized trial examining wide local excision +RT or wide local excision or mastectomy vs. active surveillance (estimated time of completion 2029)
A trial comparing surgery with active monitoring in low risk DCIS (UK-LORIS)	A phase 3 trial comparing surgery (+/− RT and/or hormonal therapy) and active monitoring. Recruitment for this trial has ended (estimated time of completion unknown).
Prospective Evaluation of Breast-Conserving Surgery Alone in Low Risk Ductal Carcinoma in Situ (ELISA)-NCT04797299	Prospective cohort study to evaluate whether the combination of clinicopathological factors and the use of Oncotype DX DCIS score can avoid radiation in women with low-risk DCIS who have had BCS (estimated time of completion 2035).
Wide Excision Alone as Treatment for Ductal Carcinoma In Situ of the Breast-NCT00165256	Phase 2 study to determine if wide excision (surgical removal) alone is adequate treatment for small, grade 1 or 2, DCIS of the breast (estimated time of completion 2023) (surgery vs. observation)
Management after DCIS after primary treatment
Radiotherapy Versus Low-Dose Tamoxifen Following Breast Conserving Surgery for Low Risk Breast Ductal Carcinoma in Situ -NCT04046159	Phase 3 trial comparing RT (50 Gy/25 fx or 40.05 Gy/15 fx) vs. low-dose tamoxifen (5 mg QD for 10 yrs) in low-risk and estrogen receptor-positive DCIS (estimated time of completion 2025)
Testing an Active Form of Tamoxifen (4-hydroxytamoxifen) Delivered through the Breast Skin to Control Ductal Carcinoma in Situ (DCIS) of the Breast-NCT02993159	Phase 2 trial comparing 2 mg once daily per breast of 4-hydroxytamoxifen topical gel vs. 20 mg daily oral tamoxifen citrate (estimated time of completion 2023)
Hypofractionated Partial Breast Irradiation in Treating Patients with Early Stage Breast Cancer-NCT03077841	Phase 2/3 trials comparing hypofractionated partial breast irradiation daily for 5 days (+possible 3 boost fractions at discretion of the doctor) vs. standard irradiation daily for 15 days (+possible 5 boost fractions at discretion of the doctor; estimated time of completion 2024).
Single-arm confirmatory trial of endocrine therapy alone for estrogen receptor-positive, low risk ductal carcinoma in situ of the breast (JCOG1505, LORETTA trial)	Trial comparing endocrine therapy alone vs. non in low-risk estrogen receptor positive patients (estimated time of completion unknown)
Molecular Testing
The AUS-PREDICT Registry for DCIS Patients with DCISionRT Testing-NCT04916808	Prospective cohort study of patients diagnosed with DCIS and to create a database of patients, test results, treatment decisions, and outcomes to determine the utility of DCISionRT (estimated time of completion 2024)
The PREDICT Registry for DCIS Patients with DCISionRT Testing NCT03448926	Prospective cohort study of patients diagnosed with DCIS and to create a database of patients, test results, treatment decisions, and outcomes to determine the utility of DCISionRT (estimated time of completion 2025)