Rethinking the Standard for Ductal Carcinoma In Situ Treatment

Abstract

The original goal of mammographic screening was to identify invasive cancers at the earliest stage, because of the superior prognosis of stage I cancers. Prior to the advent of screening, ductal carcinoma in situ (DCIS) made up approximately 3% of breast cancers detected. As we pushed to find smaller and smaller cancers, and targeted calcifications instead of just masses, we began to identify DCIS more frequently. Now DCIS accounts for approximately 20% to 25% of screen-detected breast cancers. The cells that make up DCIS look like invasive cancer both pathologically and molecularly, and therefore the presumption was made that these lesions were the precursors of cancer and that early removal and treatment would reduce cancer incidence and mortality. However, long-term epidemiology studies have demonstrated that the removal of 50 000 to 60 000 DCIS lesions annually has not been accompanied by a reduction in the incidence of invasive breast cancers.1 This is in contrast to the experience with removal of colonic polyps and intraepithelial neoplasia lesions of the cervix, in which the removal of precursor lesions has led to a decrease in the incidence of colon and cervical cancer, respectively. 2 We now know that breast cancer encompasses a range of behaviors, from aggressive to indolent; the latter are more likely to surface with screening. 3 The analysis of Narod et al 4 fuels a growing concern that we should rethink our strategy for the detection and treatment of DCIS. As demonstrated by Narod and colleagues 4 in this large observational study of more than 100 000 women with a diagnosis of DCIS, the risk of dying from breast cancer is low. Less than 1% of patients in this 20-year study died of breast cancer (compared with 5% of patients who died of other causes). Using the Kaplan-Meier method, the breast cancer-specific mortality rate is 3.3% at 20 years, not dissimilar to the statistic that the American Cancer Society 5 says is the chance that the average woman will die of breast cancer. This is welcome news and suggests that we can embrace evaluation of alternative strategies to surgery and radiation therapy. CALGB 40903, 6 a neoadjuvant study of 6 months of letrozole therapy, is an example of a new approach and should open the door to trials of observation and endocrine risk-reducing therapy. If invasive cancer develops after DCIS, the risk of dying of breast cancer increases substantially. Because the biological characteristics of DCIS often predict the type of cancer that may develop in the future, the value of a DCIS diagnosis may be in providing a clue about how to more specifically prevent a potentially lethal breast cancer.A second important insight from the article by Narod et al 4 is that there are uncommon cases in which DCIS has a higher risk than has been appreciated. When DCIS is diagnosed before the age of 35 or even 40 years, some of these lesions do pose an increased risk of breast cancer-specific mortality. Ductal carcinoma in situ diagnosed before the age of 40 years is likely different becaus...

Wherein the Authors Attempt to Minimize the Confusion Generated by Their Study “Breast Cancer Mortality after a Diagnosis of Ductal Carcinoma In Situ” by Several Commentators Who Disagree with Them and a Few Who Don’t: A Qualitative Study

“…We soon realized that many of the news articles referred not to our study, but to an accompanying editorial 14 in which Dr. Laura Esserman suggested that our findings support the notion (hers) that women with dcis might not need surgery at all and that the right approach might be to "actively monitor these women, only treating if the cancer progresses" 13 . But all the women in our study underwent surgery for dcis, and based on our findings, we cannot recommend active surveillance or withholding of treatment.…”

Upgraded Malignancy from High-Risk and Borderline Breast Lesions: Immunohistochemical and Clinical Characteristics

“…Rethinking the standard for DCIS treatment is the current research trend (15). There are many papers that distinguish prognosis or analysis of DCIS, an early cancer without invasion, from invasive ductal carcinoma (IDC) (3,15,16).…”

“…There are many papers that distinguish prognosis or analysis of DCIS, an early cancer without invasion, from invasive ductal carcinoma (IDC) (3,15,16). In this study, we also analyzed the cases that were upgraded to DCIS and IDC.…”

3D Supine Automated Ultrasound (SAUS, ABUS, ABVS) for Supplemental Screening Women with Dense Breasts

“…Increase of incremental cancer detection rate (around 2/1000 examinations) and absolute decrease of recall rate (about 1-1.5%) have been observed after implementation of 3D digital breast tomosynthesis in population-based screening trials (30)(31)(32)(33). Many logistical issues and the role of potential over-diagnosis of DCIS need further evaluation to determine the potential implications and cost of supplemental HHUS, SAUS, combined 2D + supplemental 3D mammographic screening (30)(31)(32)(33)(34)(35)(36). At present, the available data strongly support investment in new large-scale population screening trials that should use a randomized and prospective design.…”