Active Monitoring With or Without Endocrine Therapy for Low-Risk Ductal Carcinoma In Situ: The COMET Randomized Clinical Trial

E Shelley Hwang ¹, Terry Hyslop ², Thomas Lynch ¹

¹Department of Surgery, Duke University, Durham, North Carolina.
²Department of Pharmacology, Physiology, and Cancer Biology, Thomas Jefferson University, Philadelphia, Pennsylvania.
³Departments of Population Health Sciences and Mathematics, Duke University, Durham, North Carolina.
⁴Department of Surgery/Oncology, University of Rochester, Rochester, New York.
⁵Alliance Foundation Trials, Boston, Massachusetts.
⁶Aurora Health Care, Milwaukee, Wisconsin.
⁷Department of Radiology, Duke University, Durham, North Carolina.
⁸Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts.
⁹Department of Pathology and Laboratory Medicine, Emory University, Atlanta, Georgia.
¹⁰Department of Pathology, Duke University, Durham, North Carolina.
¹¹COMET Study Patient Leadership Team, Alliance Foundation Trials, Boston, Massachusetts.
¹²Department of Pathology and Immunology, Washington University in St Louis, St Louis, Missouri.
¹³Department of Pathology, Stanford University, Stanford, California.
¹⁴The VA Outcomes Group, Department of Veterans Affairs Medical Center, White River Junction Vermont and Geisel School of Medicine at Dartmouth, Hanover, New Hampshire.
¹⁵Population Health Sciences, University of Bristol, Bristol, United Kingdom.
¹⁶Division of Biostatistics/Bioinformatics, Thomas Jefferson University, Philadelphia, Pennsylvania.
¹⁷Duke Cancer Institute Biostatistics Shared Resource, Duke University, Durham, North Carolina.
¹⁸Department of Health Policy and Management, University of North Carolina at Chapel Hill.
¹⁹Division of Epidemiology, Weill Cornell University, New York, New York.
²⁰School of Medicine, Yale University, New Haven, Connecticut.
²¹Division of Breast Surgery, Medstar Washington Hospital Center, Washington, DC.
²²Department of Surgery, Cedars-Sinai Medical Center, Los Angeles, California.
²³Department of Surgery, The University of Kansas Health System, Kansas City.
²⁴Cancer Research Consortium of West Michigan NCORP, Grand Rapids.
²⁵Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania.
²⁶Metro MN Community Oncology Research Consortium, St Louis Park, Minnesota.
²⁷Department of Breast Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston.
²⁸Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill.
²⁹Department of Surgery, Baylor College of Medicine, Houston, Texas.
³⁰Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, Massachusetts.

⁰Department of Surgery, Duke University, Durham, North Carolina.

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December 12, 2024

View abstract on PubMed

Summary

Active monitoring for low-risk ductal carcinoma in situ (DCIS) is as safe as standard care. This study found no increased risk of invasive breast cancer with active monitoring over two years.

Area Of Science

Oncology
Breast Cancer Research
Clinical Trials

Background

Active monitoring for low-risk ductal carcinoma in situ (DCIS) is being explored as an alternative to standard treatment.
The safety and efficacy of active monitoring compared to guideline-concordant care for DCIS remain unknown.

Purpose Of The Study

To compare the incidence of invasive breast cancer in patients with low-risk DCIS undergoing active monitoring versus guideline-concordant care.
To determine if active monitoring is a non-inferior treatment option for low-risk DCIS.

Main Methods

A prospective, randomized noninferiority trial involving 995 women aged 40+ with low-risk DCIS.
Participants were randomized to either active monitoring (regular imaging and exams) or guideline-concordant care (surgery with or without radiation).
The primary outcome was the 2-year cumulative risk of ipsilateral invasive cancer.

Main Results

The 2-year cumulative rate of ipsilateral invasive cancer was 4.2% for active monitoring versus 5.9% for guideline-concordant care.
Active monitoring was found to be non-inferior to guideline-concordant care, with a difference of -1.7% (upper 95% CI limit of 0.95%).
No significant differences in invasive tumor characteristics were observed between the two groups.

Conclusions

Active monitoring is a safe alternative for women with low-risk DCIS, showing no increased rate of invasive cancer compared to standard care.
These findings support active monitoring as a viable option, potentially reducing overtreatment for selected DCIS patients.