Comparison of Operative to Monitoring and Endocrine Therapy (COMET) Trial For Low Risk DCIS


  • Study type

  • Study phase

  • Study IDs

  • Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.
  • During the early phases (phases 1 and 2), researchers assess safety, side effects, optimal dosages and risks/benefits. In the later phase (phase 3), researchers study whether the treatment works better than the current standard therapy. They also compare the safety of the new treatment with that of current treatments. Phase 3 trials include large numbers of people to make sure that the result is valid. There are also less common very early (phase 0) and later (phase 4) phases. Phase 0 trials are small trials that help researchers decide if a new agent should be tested in a phase 1 trial. Phase 4 trials look at long-term safety and effectiveness, after a new treatment has been approved and is on the market.

  • Site IRB
    • Jacksonville, Florida: 17-010609
    • Rochester, Minnesota: 17-010609
    • Scottsdale/Phoenix, Arizona: 17-010609
    NCT ID: NCT02926911
    Sponsor Protocol Number: AFT-25

About this study

This study looks at the risks and benefits of active surveillance (AS) compared to guideline concordant care (GCC) in the setting of a pragmatic prospective randomized trial for low risk DCIS. Our overarching hypothesis is that management of low-risk Ductal Carcinoma in Situ (DCIS) using an AS approach does not yield inferior cancer or quality of life outcomes compared to GCC.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

See eligibility criteria

Inclusion Criteria:

  • New diagnosis of DCIS without invasive cancer; date of diagnosis defined as the date of the first pathology report that diagnosed the patient with DCIS.
  • Unilateral, bilateral, unifocal, or multifocal DCIS.
  • ADH/borderline DCIS.
  • A patient who has had a lumpectomy with positive margins as part of their treatment for a current DCIS diagnosis is eligible (post-excision mammogram required at enrollment to establish a new baseline).
  • No previous history of breast cancer (DCIS or invasive cancer) in either breast prior to current DCIS diagnosis.
  • 40 years of age or older at time of DCIS diagnosis.
  • ECOG performance status 0 or 1.
  • No contraindication for surgery.
  • Baseline imaging:
    • Unilateral DCIS: contralateral normal mammogram ≤ 6 months of registration and ipsilateral breast imaging ≤ 120 days of registration (must include ipsilateral mammogram; can also include ultrasound or breast MRI);
    • Bilateral DCIS: bilateral breast imaging ≤ 120 days of registration (must include bilateral mammogram; can also include ultrasound or breast MRI).
  • Pathologic Criteria:
    • All grade I DCIS (irrespective of necrosis/comedonecrosis);
    • All grade II DCIS (irrespective of necrosis/comedonecrosis).
  • Absence of invasion or microinvasion.
  • Diagnosis confirmed on core needle, vacuum-assisted or surgery ≤ 120 days of registration.
  • ER(+) and/or PR(+) by IHC (≥ 10% staining or Allred score ≥ 4).
  • HER2 0, 1+, or 2+ by IHC if HER2 testing is performed.
  • Histology slides reviewed and agreement between two clinical pathologists (not required to be at same institution) that pathology fulfills COMET eligibility criteria. In cases of disagreement between the two pathology reviews about whether or not a case fulfills the eligibility criteria, a third pathology review will be required.
  • At least two sites of biopsy for those cases where mammographic extent of calcifications exceeds 4 cm, with second biopsy benign or both sites fulfilling pathology eligibility criteria.
  • Amenable to follow up examinations.
  • Ability to read, understand and evaluate study materials and willingness to sign a written informed consent document.
  • Reads and speaks Spanish or English.

Exclusion Criteria:

  • Male DCIS.
  • All Grade III DCIS.
  • Concurrent diagnosis of invasive or microinvasive breast cancer in either breast.
  • Documented mass on examination or imaging, or diagnosis of mass as cyst, at site of DCIS prior to biopsy yielding diagnosis of DCIS, with exception of fibroadenoma at a distinct/separate site from site of DCIS (or diagnosis of mass as a cyst). In cases of uncertainty about whether the mass was present on physical examination prior to biopsy, the following criteria should be applied: if mammogram noting abnormal findings is diagnostic MMG = symptomatic/if mammogram noting abnormal findings is screening MMG = asymptomatic.
  • Bloody nipple discharge (ipsilateral breast).
  • Mammographic finding of BIRADS 4 or greater within 6 months of registration at site other than that of known DCIS, without pathologic assessment.
  • Use of investigational cancer agents within 6 weeks prior to diagnosis.
  • Any serious and/or unstable pre-existing medical, psychiatric, or other existing condition that would prevent compliance with the trial or consent process.
  • Pregnancy. If a woman has been confirmed as pregnant she will not be eligible to take part in the trial. If she suspects there is a chance that she may be pregnant, a pregnancy test should be undertaken; however, a pregnancy test for all women of child-bearing potential is not mandatory.
  • Documented history of prior tamoxifen, aromatase inhibitor, or raloxifene in last 6 months.


Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status Contact

Jacksonville, Fla.

Mayo Clinic principal investigator

Sandhya Pruthi, M.D.

Contact us for the latest status

Contact information:

Pulkit Mathur


Rochester, Minn.

Mayo Clinic principal investigator

Sandhya Pruthi, M.D.

Open for enrollment

Contact information:

Jean Jensen


Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

Sandhya Pruthi, M.D.

Open for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office



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