Meta‐analysis on axillary lymph node metastasis rate in ductal carcinoma in situ with microinvasion

Objective To address the question of axillary lymph node staging in ductal carcinoma in situ with microinvasion (DCIS‐MI), we retrospectively evaluated axillary lymph nodes metastasis (ALNM) rate in a cohort of postsurgical DCIS‐MI patients. By analyzing these data, we aimed to generate clinically relevant insights to inform treatment decision‐making for this patient population. Methods A systematic search was conducted on PubMed, Web of Science, Embase, The Cochrane Library, CNKI, Wanfang Database, Wipe, and China Biomedical Literature Database to identify relevant publications in any language. All the analyses were performed using Stata 16.0 software. Results Among the 28 studies involving 8279 patients, the pooled analysis revealed an ALNM rate of 8% (95% CI, 7% to 10%) in patients with DCIS‐MI. Furthermore, the rates of axillary lymph node macrometastasis, micrometastasis, and ITC in patients with DCIS‐MI were 2% (95% CI, 2% to 3%), 3% (95% CI, 2% to 4%), and 2% (95% CI, 1% to 3%), respectively. Moreover, 13 studies investigated the non‐sentinel lymph node (Non‐SLN) metastasis rate, encompassing a total of 1236 DCIS‐MI cases. The pooled analysis identified a Non‐SLN metastasis rate of 33% (95% CI, 14% to 55%) in patients with DCIS‐MI. Conclusion The SLNB for patients with DCIS‐MI is justifiable and could provide a novel therapeutic basis for systemic treatment decisions.