Is axillary surgery still justified in DCIS diagnosed via vacuum-assisted biopsy?

Background: The role of axillary surgery in ductal carcinoma in situ (DCIS) remains controversial, particularly for cases diagnosed via vacuum-assisted biopsy (VAB), which may reduce "upstage" to invasive disease. This study evaluates the incidence of axillary metastasis and pathologic upstaging in DCIS to identify subgroups where axillary staging can be safely omitted.

Methods: A retrospective cohort of 494 patients with pure DCIS diagnosed by VAB (2011-2019) was analyzed. Patients were stratified by age, nuclear grade, comedonecrosis, and surgical approach (breast-conserving surgery [BCS] vs. mastectomy). Axillary management included sentinel node biopsy (SNB), axillary dissection (AD), or omission. Multivariate logistic regression identified predictors of axillary surgery and upstaging to invasive carcinoma.

Results: Most patients underwent BCS (72.7%), with axillary evaluation performed in 35.1% of BCS cases versus 91.9% of mastectomies (p < 0.001). Only 3.8% (19/494) were upstaged to invasive carcinoma, and nodal involvement occurred in 1.2% (3/250) of axillary procedures-all in patients with invasive foci on final pathology. No pure DCIS cases had nodal metastasis. Younger age (< 40 years, p = 0.039), high nuclear grade (grade 3, p = 0.006), and mastectomy (p < 0.001) independently predicted axillary surgery. Comedonecrosis and palpable lesions were associated with higher SNB rates but not nodal positivity.

Conclusions: Routine axillary surgery is unnecessary in VAB-diagnosed DCIS. Omission of SNB appears safe for patients undergoing BCS without high-risk features (palpability, high grade). Axillary staging may be reserved for mastectomy candidates or those with suspicions imaging of invasive disease.