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What is the COMET Study?

COMET stands for Comparison of Operative to Monitoring and Endocrine Therapy for low-risk ductal carcinoma in situ (DCIS). This is the first large phase III randomized clinical trial in the United States (US) to look at different management strategies for low-risk DCIS. The COMET Study will enroll 1200 women with low-risk DCIS at about 100 cancer centers throughout the US. The study is funded by the Patient-Centered Outcomes Research Institute (PCORI).

Why is the COMET Study needed?

Currently, many types of DCIS are treated the same as invasive breast cancer. Surgery and radiation are considered standard care in the US. Endocrine (hormone-blocking) therapy is also often recommended. This is usually a pill taken once a day for five years. These treatments may bring significant physical, emotional, and financial burdens to a woman’s life. Potential side effects of surgery may be short or long term and include pain, infection, scarring, loss of feeling, depression, and anxiety; potential side effects of radiation include damage to lungs, heart, thyroid, bones, joints and other organs, as well as increased risk of other cancers.

Studies have shown 70-80% of DCIS may never become invasive breast cancer even when DCIS is left untreated. Many breast cancer doctors and researchers now believe that low-risk DCIS is being over-treated. They also suggest that these women may have the same excellent outcomes with close monitoring. This is known as active surveillance. Instead of having immediate surgery, a woman will be monitored with more frequent follow-up exams and tests such as mammograms. A biopsy or surgery will be recommended if tests show changes that require further evaluation.

The COMET Study will provide information to better understand low-risk DCIS. In particular, it will provide information on the trade-offs between immediate standard treatment (surgery and possibly radiation) and active surveillance. This will help determine if more patients are able to avoid aggressive ‘cancer’ treatments and their potential side effects. It will also help to personalize treatment choices. These choices may better reflect individual values and preferences. Currently, all women diagnosed with DCIS are treated as if they have invasive breast cancer. We hope that the COMET Study will show that active surveillance is equally as safe and effective as surgery for women with low-risk DCIS.

What can I expect if I participate in the COMET Study?

The COMET study will look at two different interventions for DCIS:

  1. Standard care. This is likely to include surgery (lumpectomy or mastectomy) and possibly radiation therapy. Follow-up exams are every six months and mammograms are yearly.
  2. Active surveillance. This includes mammograms and physical exams every six months. Surgery is only recommended if needed.

In either group, you and your doctor will decide whether endocrine (hormone-blocking) therapy is a good option.

Once you join the trial, you will be randomized to one of these two groups. This will be done by chance, using a computer. You will not get to choose which group you are assigned to. This is done to achieve the best study results. It ensures that both groups are similar and avoids any bias. It is also done because we don’t know if one intervention is better than the other.

Throughout the study, you will be asked to complete surveys. These surveys will ask about your quality of life and treatment or surveillance experience. The surveys are very important. They will help to compare risks and benefits between standard care and active surveillance. They will also enable a better understanding of the DCIS experience.

The study will last a minimum of five years. However, the study team may ask you to remain in the study and follow your progress for up to ten years.

How will I be monitored in the COMET Study?

Throughout the study, you will be regularly monitored by your surgeon and possibly a medical or radiation oncologist. In addition, you will have a clinical trial support team. Over the course of the five-year study, you will receive periodic screening and access to specialist advice. Regular follow-up examinations will include mammograms, ultrasounds or MRIs. If you are assigned to the active surveillance group, you will have a mammogram every six months (as opposed to every 12 months in the standard care group).

If changes in the breast are found on a mammogram, a biopsy (tissue sample taken from the breast) may be recommended. If the biopsy shows invasive cancer you may be treated with standard care (breast surgery and sometimes radiation therapy). Endocrine (hormone-blocking) therapy may also be recommended.

What happens if I want to leave the COMET Study?

You are free to leave the COMET Study at any time. For example, if you are assigned to a group that you do not wish to join, you can leave, although we will request that you continue to complete the surveys. There will be no penalty or loss of benefits to you, and you will not lose medical care or any legal rights. During the course of this study, the clinical trial staff and your physician will help guide you through these decisions.

The COMET Study Team

This website aims to provide information for women diagnosed with DCIS, such as new progress in DCIS research, support materials for making decisions and a list of frequently asked questions. The website also provides specific details about the Comparison of Operative to Monitoring and Endocrine Therapy for Low-Risk DCIS (COMET) Study, a clinical trial hosted within a national co-operative group network — the Alliance for Clinical Trials in Oncology — and funded by the Patient-Centered Outcomes Research Institute (PCORI). The Principal Investigator (PI) of COMET is Dr. Shelley Hwang, Professor of Surgery and Chief of Breast Surgical Oncology at the Duke University Medical Center and Duke Cancer Institute. Co-PIs of the study are Dr. Alastair Thompson, a breast Surgical Oncologist and Professor of Surgery at MD Anderson Cancer Center, and Dr. Ann Partridge, a breast Medical Oncologist and Associate Professor of Medicine at Harvard Medical School. Much of the material that you will see on the website has been compiled by the COMET Study Patient Leadership Team (PLT): Liz Frank; Deborah Collyar; Desiree Basila; and Donna Pinto. Members of the PLT possess vast DCIS experience and expertise including: engagement in breast cancer research for over 20 years; undergoing active surveillance for DCIS; publishing a DCIS e-book; developing a patient advocate research organization; and hosting a DCIS website. Translation of materials into Spanish has been provided by Celia Kaplan, PhD, a patient advocate and Professor in the Department of Medicine, Division of General Internal Medicine, University of California, San Francisco. The Project Manager of the COMET study is Thomas Lynch, PhD, a researcher working in the Division of Surgical Oncology at Duke University Medical Center.


Some members of the COMET Study Patient Leadership Team

Some members of the COMET Study Patient Leadership Team

Dr. Shelley Hwang, Principal Investigator of the COMET Study

Dr. Shelley Hwang, Principal Investigator of the COMET Study

Some members of the COMET Study Team

Some members of the COMET Study Team

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