DCIS: RECAST Trial Ductal Carcinoma In Situ: Re-Evaluating Conditions for Active Surveillance Suitability as Treatment

The film gives the main points. The full list below is copied from the registry; the study team makes the final decision.

• Age18 Years to no maximum
• SexFemale
• Healthy volunteersNo

You may be able to join if

• A. Female, at least 18 years old
• B. Previous diagnosis of HR+ DCIS (at least 50% ER or PR; biopsy will have been performed previously at diagnosis) with or without microinvasion
• Patients with a diagnosis of hormone positive DCIS who have undergone surgery with positive margins that have not been re-excised are candidates to enroll in the trial.
• C. Patients who have previously received endocrine therapy should have a washout period of at minimum 4-6 weeks prior to the screening MRI on the RECAST-DCIS trial
• D. Bilateral mammogram performed within up to 6 months (180 days) of the start of trial treatment may be used for screening evaluation. If a bilateral mammogram has been performed within 1 year (12 months) of the start of trial treatment, then a diagnostic unilateral mammogram within 6 months (180 days) of the start of trial treatment will be acceptable for screening evaluation.
• E. MRI performed on an I SPY (RECAST) approved scanner within 2 months (60 days) of the start of trial treatment for lesion evaluation may be used for screening evaluation.
• F. CBC w/ diff, CMP, and Lipid Panel within normal limits within a year of the start of trial treatment. Abnormal labs to be repeated within 60 days prior to the start of trial treatment. Patients will be considered eligible for screening labs that are abnormal or out-of-range if the investigator has deemed the lab results not-clinically significant
• G. Negative urine or serum pregnancy test within 1 month of the start of trial treatment
• H. Controlled HIV positive patients are allowed as long as their current medication does not contraindicate the study's investigational agent
• I. Willingness and ability to provide tumor samples for research

You cannot join if

• A. Pregnant or actively breastfeeding women
• B. History of allergic reactions attributed to compounds of similar chemical or biologic composition to study agent based on review of the medical record and patient history
• C. Invasive carcinoma or identification of a mass on MRI that is subsequently biopsied and found to be invasive cancer
• D. Co-enrollment in clinical trials of pharmacologic agents requiring an IND
• E. Ongoing treatment for DCIS other than what is specified in this protocol
• F. Uncontrolled intercurrent illness, including psychiatric conditions, that would limit compliance with study requirements
• G. Medical history or ongoing gastrointestinal disorders potentially affecting the absorption of investigational agent and/or tamoxifen. Active inflammatory bowel disease or chronic diarrhea, known active hepatitis A/B/C*, hepatic cirrhosis, short bowel syndrome, or any upper gastrointestinal surgery including gastric resection or banding procedures
• Active hepatitis, defined as: A (positive HA antigen or positive IgM); B (either positive HBs antigen or positive hepatitis B viral DNA test above the lower limit of detection of the assay); C (positive hepatitis C antibody result, and quantitative hepatitis C (HCV) ribonucleic acid (RNA) results greater than the lower limits of detection of the assay)
• H. Participants who are unable to swallow normally or unable to take tablets and capsules. Predictable poor compliance with oral treatment
• I. Participants with substantial MRI artifacts (e.g., related to localizer sequences, cardiac devices such as pacemakers, or other hardware) that render the lesion non-evaluable.
• J. Severe allergy or reaction history to MRI contrast.
• K. Participants currently undergoing or who have received treatment for another malignancy within the previous 6 months.

This is how the treatment is meant to work. Whether it helps, and how safe it is, is what this trial is testing.

elacestrant hydrochloride. The hydrochloride salt form of elacestrant, an orally available, selective estrogen receptor degrader (SERD), with antineoplastic activity. Upon oral administration, elacestrant acts as a SERD, which binds to the estrogen receptor (ER) and induces a conformational change that results in the proteosomal degradation of the receptor. This prevents ER-mediated signaling and inhibits proliferation of ER-expressing cancer cells. NCI Drug Dictionary

Treatments listed in the registry

• Tamoxifen (Drug): For premenopausal women: 20 mg tamoxifen orally daily (standard dose) or 10 mg every other day (low dose). For postmenopausal women who are not tolerating an AI, investigators can change them to the low dose (10 mg every other day) or standard dose (20 mg) of tamoxifen.
• Exemestane (Drug): For postmenopausal women: standard oral doses of AI of choice: exemestane 25 mg daily, or reduced exemestane dosing: 25 mg 3 times per week orally
• Letrozole (Drug): For postmenopausal women: standard oral doses of AI of choice: letrozole 2.5 mg daily.
• Anastrazole (Drug): For postmenopausal women: standard oral doses of AI of choice: anastrozole 1 mg daily.
• Testosterone + Anastrazole (Drug): Investigational drug. Both pre- and post- menopausal subjects. 100mg testosterone in combination with 4mg anastrazole administered subcutaneously every 3 months for up to 3 years.
• Elacestrant (Drug): Investigational drug. Both pre- and post- menopausal subjects. Elacestrant 400mg PO with food once daily up to 36 months.
• Z-endoxifen (Drug): Investigational drug. Both pre- and post- menopausal subjects. (z)-endoxifen 10mg delayed release capsule 1 hour before a meal or 2 hours after a meal once daily for up to 36 months.

Randomized · Parallel · masking: None

As the registry describes them. Requirements to join, such as a tissue sample, are in the eligibility list above even when on-study procedures are optional. Ask the study team which steps apply to you.

• blood samples: Part of the study plan
• MRI: Part of the study plan
• surgery: Part of the study plan

Main goals

• Patients remaining on active surveillance at 7 months (7 months)

Other goals

• To determine whether novel endocrine therapy increases the fraction of patients who will be suitable for long-term active surveillance as measured by the fraction of patients deemed to be low-risk for invasive cancer at 6 months compared to control
• To determine whether novel endocrine therapy increases the fraction of patients who will be suitable for long-term active surveillance as measured by the fraction of patients deemed to be low-risk for invasive cancer at 3 months compared to control
• Associate rate of progression to Invasive Ductal Carcinoma (IDC) with risk categorization after 6 months of treatment at 3 years
• To assess the QoL impact of novel endocrine therapy compared to tamoxifen or Aromatase inhibitor (Ai) at standard or low dose using PROMIS and the FACT-ES and FACT-GP5 composite score compared to control
• For those with an identified lesion on MRI imaging, determine whether neoadjuvant endocrine therapy decreases lesion volume (qualitative, quantitative) and whether that corresponds to the biologic type of Ductal cell carcinoma In Situ (DCIS)
• To determine whether neoadjuvant endocrine therapy decreases automated background parenchymal enhancement (BPE and automated MRI density compared to Ai and Tamoxifen
• Determine adherence to active surveillance protocol
• Change in artificial intelligence predicted risk based on mammography

Planned enrollment: 400 (estimated).

• Berkeley Outpatient Center, Berkeley, California
• City of Hope -Duarte Cancer Center, Duarte, California
• City of Hope - Lennar Foundation Cancer Center, Irvine, California
• UCLA, Los Angeles, California
• UCSF, San Francisco, California
• City of Hope, South Pasadena, California
• John Muir Health, Walnut Creek, California
• MedStar Washington Hospital Center, Washington D.C., District of Columbia
• Moffitt Cancer Center, Tampa, Florida
• Winship Cancer Institute, Emory University, Atlanta, Georgia
• University of Chicago Medical Center, Chicago, Illinois
• Maple Grove Cancer Center, Maple Grove, Minnesota
• Hennepin Healthcare -Minneapolis, Minneapolis, Minnesota
• University of Minnesota, Minneapolis, Minnesota
• Health Partners - Frauenshuh Cancer Center, Saint Louis Park, Minnesota
• Health Partners - Regions Hospital, Saint Paul, Minnesota
• Englewood Hospital and Medical Center, Englewood, New Jersey
• Mount Sinai Union Square, New York, New York
• Mount Sinai Chelsea, New York, New York
• Mount Sinai West, New York, New York
• Icahn School of Medicine at Mount Sinai, New York, New York
• Montefiore Medical Center (Hutchinson Campus Tower 1), The Bronx, New York
• Duke Cancer Institute, Durham, North Carolina
• Atrium Health Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina
• Vanderbilt University Medical Center, Nashville, Tennessee
• Huntsman Cancer Institute, Salt Lake City, Utah
• Virginia Commonwealth University, Richmond, Virginia

Site status as of Oct 30, 2026. Check the live record before contacting a site.

• ClinicalTrials.gov NCT06075953
• NCI Drug Dictionary: C171898

Registry record reviewed as fetched Oct 30, 2026, last updated by the sponsor Oct 25, 2026. Public record; not medical advice.