Comparing an Operation to Monitoring, With or Without Endocrine Therapy (COMET) Trial For Low Risk DCIS

Overdiagnosis and overtreatment resulting from mammographic screening have been estimated to be as high as 1 in 4 patients diagnosed with breast cancer although the absence of standard definitions for measuring overdiagnosis has led to much uncertainty around this estimate. The national health care expenditure resulting from false positive mammograms and breast cancer overdiagnosis has been estimated to approach $4 billion annually. There is general consensus that much of this burden derives from the treatment of DCIS; for those estimated 40,000 women per year whose DCIS may never have progressed even without treatment, medical intervention can only harm. In those women who undergo surgical management of DCIS, there is risk of developing persistent pain at the surgical site, with estimates ranging from 25-68%. Importantly, persistent pain after lumpectomy may be as prevalent as that after total mastectomy. Persistent postsurgical pain is rated by patients as the most troubling symptom, leading to disability and psychological distress, and is often resistant to management. Although prospective population-based data have demonstrated significant patient and surgical focus on pain with remarkably high levels of chronic pain 4 and 9 months after breast surgery, much of these data have been collected in women with invasive cancer, with little data directly relevant to patients with DCIS. The overarching hypothesis of the study is that management of low-risk DCIS using an active monitoring (AM) approach does not yield inferior cancer or quality of life outcomes compared to surgery.