Comparison of Operation to Monitoring With/Without Endocrine Therapy For Low Risk DCIS


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. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria:

  • Diagnosis of unilateral, bilateral, unifocal, multifocal, or multicentric DCIS without invasive breast cancer (date of diagnosis defined as the date of the first pathology report that diagnosed the patient with DCIS) OR: atypia verging on DCIS OR: DCIS + LCIS (mix and/or separate locations in the same breast).
  • A patient who has had a lumpectomy or partial mastectomy with margins positive for DCIS (i.e. < 2 mm/ink on tumor) as part of their treatment for a current DCIS diagnosis is also eligible (post-excision bilateral mammogram required at enrollment to establish a new baseline).
  • No previous DCIS or invasive breast cancer in ipsilateral breast 5 years 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 (must include dimensions):
    • 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);
    • DCIS s/p lumpectomy:  post excision mammogram on side of excision ≤ 60 days of registration.
  • Pathologic criteria:
    • All grade I DCIS (irrespective of necrosis/comedonecrosis);
    • All grade II DCIS (irrespective of necrosis/comedonecrosis);
    • Absence of invasion or microinvasion;
    • Diagnosis of DCIS confirmed on core needle biopsy, vacuum-assisted biopsy, or surgery ≤ 120 days of registration;
    • ER(+) and/or PR(+) by IHC (≥ 10% staining or Allred score ≥ 4) unless atypia verging on DCIS in which case biomarker criterion does not apply;
    • 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 fulfils COMET eligibility criteria. In cases of disagreement between the two pathology reviews about whether or not a case fulfils the eligibility criteria, a third pathology review will be required.
  • At least two sites of biopsy for those cases where individual mammographic extent of calcifications exceeds 4 cm, with second biopsy benign or both sites fulfilling pathology eligibility criteria (ER/PR testing required for second biopsy).
  • 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:

  • All grade III DCIS.
  • Male DCIS.
  • Concurrent diagnosis of invasive or microinvasive breast cancer in either breast.
  • Documented mass on examination or mass/hypoechoic area on imaging at site of DCIS prior to biopsy yielding diagnosis of DCIS, with exception of: subsequent lumpectomy or partial mastectomy (with positive DCIS margins; i.e., < 2 mm/ink on tumor) followed by a post-surgery MMG; fibroadenoma at a distinct/separate site from site of DCIS; or diagnosis of mass/hypoechoic area as a cyst or a papilloma. 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. If a patient has a mass on imaging that is biopsied (worked-up) and does not show invasive breast cancer, they are eligible. If a patient has a mass on initial MMG that is not seen on subsequent MMG, they are eligible (if initial mass occurred due to additional work-up).
  • Any color/bloody nipple discharge (ipsilateral breast).
  • Mammographic finding of BIRADS 4 or greater within 6 months prior to registration at site of breast other than that of known DCIS, without pathologic assessment.
  • Use of investigational cancer agents within 6 weeks prior to diagnosis of DCIS.
  • 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, although a pregnancy test for all women of child-bearing potential is not mandatory. In addition, if a woman becomes pregnant once registered to the trial, she can continue to be followed (endocrine therapy is not a mandatory requirement of the study).
  • Documented history of prior tamoxifen, aromatase inhibitor, or raloxifene use in the 6 months prior to registration.
  • Current use of exogenous hormones (i.e., oral progesterone).

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Jacksonville, Fla.

Mayo Clinic principal investigator

Sarah McLaughlin, M.D.

Closed for enrollment

Contact information:

Pulkit Mathur

Rochester, Minn.

Mayo Clinic principal investigator

Sandhya Pruthi, M.D.

Closed for enrollment

Contact information:

Jean Jensen

(507) 538-1115

Scottsdale/Phoenix, Ariz.

Mayo Clinic principal investigator

Patricia Cronin, M.D.

Closed for enrollment

Contact information:

Cancer Center Clinical Trials Referral Office

(855) 776-0015

More information


  • The significant increase in the detection and treatment of ductal carcinoma in situ (DCIS) since the introduction of screening mammography has not been accompanied by the anticipated reduction in invasive breast cancer (IBC) incidence. The prevalence of DCIS requires a reexamination of the population level effects of detecting and treating DCIS. To further our understanding of the possible impact of DCIS diagnosis and treatment on IBC incidence in the U.S., we simulated breast cancer incidence over 25 years under various assumptions regarding the baseline incidence of IBC and the progression of DCIS to IBC. The simulations demonstrate a tradeoff between the expected increased incidence of IBC absent any DCIS detection and treatment and the rate of progression of DCIS to IBC. Our analyses indicate that a high progression of DCIS to IBC implies a significant increase in incidence of IBC over what is observed had we not detected and treated DCIS. Conversely, if we assume that there would not have been a significant increase over and above the observed incidence evident in SEER, then our model indicates that the rate of DCIS progression to clinically significant IBC is low. Given the tradeoff illustrated by our model, we must reevaluate the assumption that DCIS is a short-term obligate precursor of invasive cancer and instead focus on further exploration of the true natural history of DCIS. Read More on PubMed
  • Ductal carcinoma in situ represents about 20% of all tumours diagnosed within mammographic screening programs. The natural history of DCIS is poorly understood, as it cannot be observed directly. Estimates of the proportion of DCIS that progress to invasive cancer, as well as factors that may influence progression, are important for clinical management. Here we review various sources of evidence regarding the natural history of DCIS. Read More on PubMed
  • With the large number of women having mammography-an estimated 28.4 million U.S. women aged 40 years and older in 1998-the percentage of cancers detected as ductal carcinoma in situ (DCIS), which has an uncertain prognosis, has increased. We pooled data from seven regional mammography registries to determine the percentage of mammographically detected cancers that are DCIS and the rate of DCIS per 1000 mammograms. Read More on PubMed
  • Despite encouraging results from screening trials the efficacy of mammography in reducing mortality remains somewhat controversial. Five studies have been done in Sweden. This overview, based on 282,777 women followed for 5-13 years in randomised trials in Malmö, Kopparberg, Ostergötland, Stockholm, and Gothenburg, reveals a 24% (95% confidence interval 13-34%) significant reduction of breast cancer mortality among those invited to mammography screening compared with those not invited. To avoid the potential risk of differential misclassification causes of death were assessed by an independent end-point committee after a blinded review of all fatal breast cancer cases. The mortality reduction was similar, irrespective of the end-point used for evaluation ("breast cancer as underlying cause of death" or "breast cancer present at death"). There was a consistent risk reduction associated with screening in all studies, although the point estimate of the relative risk for all ages varied non-significantly between 0.68 and 0.84. The cumulative breast cancer mortality by time since randomisation was estimated at 1.3 per 1000 within 6 years in the invited group compared with 1.6 in the control group. The corresponding figures after 9 years are 2.6 and 3.3 and after 12 years 3.9 and 5.1. The largest reduction of breast cancer mortality (29%) was observed among women aged 50-69 at randomisation. Among women 40-49 there was a non-significant 13% reduction. In this younger age group cumulative breast cancer mortality was similar in the invited and control group during the first 8 years of follow-up. After 8 years there was a difference in favour of the invited women. There was no evidence of any detrimental effect of screening in terms of breast cancer mortality in any age group. Among women aged 70-74 years screening seems to have had only a marginal impact. Read More on PubMed

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