From overtreatment to precision: a new clinical standard for DCIS management

Article Figures & Data

Table 1

Margin width and radiotherapy decision grid in DCIS

Margin status	Radiotherapy use	Clinical interpretation
≥ 2 mm	Yes	Optimal balance between local control and cosmetic outcome
> 2 mm	Yes	No evidence that wider margins further reduce recurrence risk
< 2 mm	Yes	Re-excision may be considered based on extent of disease, imaging findings, and surgical feasibility
Any margin	No	Higher risk of ipsilateral breast events; careful patient selection required

Table 2

Key clinical trials evaluating active surveillance and biological risk stratification in DCIS

Study/Trial	Population	Management strategy	Key findings
COMET	Low-risk, hormone receptor-positive DCIS	Active surveillance vs. guideline-concordant standard therapy	Non-inferior short-term invasive cancer rates; quality-of-life advantages under evaluation
LORIS	Screen-detected low- or intermediate-grade DCIS	Surgery vs. active surveillance	Approximately 20% upgrade to invasive carcinoma at surgical excision
LORD	Low-grade (grade I–II) DCIS	Active surveillance	Feasibility demonstrated; long-term oncologic safety pending
ECOG-ACRIN E5194/Ontario cohort	Selected DCIS treated with excision alone	Genomic risk stratification	DCIS score™ predicts both invasive and in situ recurrence

Table 3

Clinical risk stratification framework for DCIS

Risk category	Defining features	Recommended management approach
Low risk	Low- to intermediate-grade DCIS, small lesion size, favorable biology, low DCIS score™	Breast-conserving surgery ± endocrine therapy; consideration of treatment de-escalation within clinical trials
Intermediate risk	Discordant clinicopathologic features, intermediate DCIS score™, close but negative margins	Breast-conserving surgery with radiotherapy and/or endocrine therapy; individualized decision-making
High risk	High-grade disease, comedo necrosis, extensive disease, high DCIS score™, or suspicion of invasion	Surgery with radiotherapy ± endocrine therapy; sentinel lymph node biopsy when mastectomy is planned or when invasion can not be excluded