So, we have an underestimation of invasive breast cancer at DCIS diagnosis. A very elegant meta-analysis of 7,350 patients reported that even if we take patients with non–high-grade, very-small DCIS, we’re still looking at an upgrade to invasive cancer of about 20% (Radiology 2011;260:119-28). The best and most recent studies of MRI and DCIS again found a diagnostic upgrade of about 27%. There were no MRI features correlating with invasive breast cancer, and this resulted in a 31% increase in procedures and more biopsies with the use of MRI.
So where are we? In active surveillance of 14 patients with DCIS at the University of California, San Francisco, 8 went on to surgery at a median follow-up of 28 months, and 5 of the 8 (62%) had invasive breast cancer (The Breast 2011;20:529-33).
What’s the cost to the health care system of surveillance if we biopsy only the DCIS and follow it without surgery or other adjuvant therapies? The psychological cost to our patients? What is the natural history of DCIS if left in place? What will be the result of microcalcifications? How are we going to follow this? What are the criteria that we will use for repeat biopsy? This really is not known.
Which are the patients that we’re going to select for observation alone? There are trials in Europe that have begun or will begin to address the safety of just observing DCIS without surgery and other therapies.
The United Kingdom Low-Risk DCIS Trial is randomizing patients with low and intermediate grade DCIS of any size to biopsy alone without surgical intervention (active monitoring) or standard therapy. Another trial, a joint Dutch Breast Cancer Research Group and European Organization for the Research and Treatment of Cancer trial is randomizing women with low-risk, low-grade DCIS to active surveillance or standard treatment. If we look at M.D. Anderson’s data and our National Cancer Database, only about 10%-15% of patients would be eligible for the latter study. I don’t think with these numbers we’d have a great impact, but it is a start.
I submit that the best U.S. patients to study will be patients with a diagnosis of atypical ductal hyperplasia (generally the smallest lesions and perhaps the earliest form of DCIS) because we have about 100,000 cases each year.
What’s the patient’s perspective? What about the need for continued repeat biopsies, and how this will affect their overall quality of life? Do patients in the United States really want to observe the DCIS in an era when our patients are requesting more and more mastectomy with reconstruction and contralateral mastectomy at diagnosis of DCIS? I seriously doubt that our patients in the United States would agree to be randomized in DCIS trials to no treatment at all. I really don’t know.
Dr. Kuerer is a professor of surgery at the University of Texas M.D. Anderson Cancer Center, Houston. He reported financial associations with Gerson Lehrman Group and McGraw-Hill Publishing.