Current trials to reduce surgical intervention in ductal carcinoma in situ of the breast: Critical review

Abstract

The high proportion of ductal carcinoma in situ (DCIS) presented in mammographic screening and the relatively low risk of progression to invasive disease have raised questions related to overtreatment. Following a review of current DCIS management protocols a more conservative approach has been suggested. Clinical trials have been introduced to evaluate the option of avoiding surgical intervention in a proportion of patients with DCIS defined as "low-risk" using certain clinicopathological criteria. These trials can potentially provide evidence-based models of active surveillance (with or without endocrine therapy) as a future management approach. Despite the undisputable fact of our need to address the obvious overtreatment of screen-detected DCIS, some important questions need to be considered regarding these trials including the eligibility criteria and definition of risk, the proportion of patient eligible for inclusion, and the length of time required for proper analysis of the trials' outcome in view of the long-term natural history of DCIS progression particularly the low-risk group. These factors can potentially affect the practicality and future impact of such trials. This review provides critical analysis of current DCIS management trials and highlights critical issues related to their practicality and the expected outcome.

Significant inter- and intra-laboratory variation in grading of ductal carcinoma in situ of the breast: a nationwide study of 4901 patients in the Netherlands

“…Nevertheless, standard treatment of DCIS currently consists of either mastectomy or breast-conserving surgery followed by radiotherapy and/or followed by endocrine therapy [6]. In addition, standard treatment decisions are made regardless of histologic grade, while progression risk or at least speed of progression is higher for high-grade lesions [7, 8]. …”

Behaviour and characteristics of low‐grade ductal carcinoma in situ of the breast: literature review and single‐centre retrospective series

“…Some studies suggest that low‐grade DCIS is being overtreated as it generally carries a very good prognosis. Clinical trials are ongoing to explore the feasibility of active surveillance as opposed to surgical intervention to manage this particular subgroup of DCIS. We recorded only one (0.5%) breast cancer‐specific death in our cohort of patients, and this was due to metastasis from a contralateral IDC.…”

“…As these trials are testing the feasibility of an active surveillance programme, only biopsies of the tumours are taken. This may not be representative of the entire lesion, especially when DCIS is known to be heterogeneous, and intermediate‐, high‐grade or even invasive foci could have been missed …”

“…Currently, the standard management for DCIS is surgical excision, usually with adjuvant radiotherapy, regardless of nuclear grade. Although the majority of DCIS are treated with breast‐conserving surgery (BCS), there is a significant proportion of patients who receive or who are later converted to mastectomy . This has led to concerns of overtreatment, particularly of low‐grade DCIS which, at least when present in a localised limited form, may be less likely to progress to IBC …”

Overcoming overuse: the way forward is not standing still—an essay by Steven Woloshin and Lisa M Schwartz

“…Action to mitigate the harms of overdiagnosis has also led to important changes, perhaps most notably in cancer treatment. Active surveillance is now the preferred option for men with low risk prostate cancers,9 major cancer centres offer this strategy for low risk papillary thyroid cancer,10 and trials are testing it for ductal carcinoma in situ 11…”