Although microinvasion (Mi) is often thought to be an interim stage between ductal carcinoma in situ (DCIS) and established invasive ductal carcinoma, survival outcomes and biological behaviour of DCIS-Mi are still poorly understood. This study investigated the potential influence of Mi on disease-free survival (DFS) and assessed its correlations with clinicopathological parameters, prognosis, molecular, and immune markers. CD4, CD8, forkhead box P3 (FOXP3), CD68, CD163, programmed cell death protein 1 (PD-1), and its ligand (PD-L1) expression in pure DCIS and DCIS-Mi, from a cohort of 198 patients, were determined by immunohistochemistry. DFS, clinicopathological parameters, immune markers, and biomarker expression were correlated with presence of Mi. Twelve out of 198 DCIS cases were associated with Mi. DCIS-Mi was significantly linked with ipsilateral invasive recurrence (p = 0.032). Kaplan-Meier analysis revealed that DCIS-Mi had worse DFS for ipsilateral invasive recurrence (p = 0.011) and this was affirmed by multivariate Cox regression analysis (95% CI 1.181–9.010, HR = 3.262, p = 0.023). DCIS-Mi was associated with higher densities of immune infiltrates positive for CD4 (p = 0.037), FOXP3 (p = 0.037), CD163 (p = 0.01), and PD-L1 (p = 0.015). This study demonstrated that DCIS-Mi was correlated with high densities of immune infiltrates and predicted ipsilateral invasive recurrence.

虽然微浸润（Mi）通常被认为是导管原位癌（DCIS）和已建立的浸润性导管癌之间的过渡阶段，但对DCIS-Mi的生存结果和生物学行为仍知之甚少。这项研究调查了Mi对无病生存（DFS）的潜在影响，并评估了其与临床病理参数，预后，分子和免疫标志物的相关性。来自198例患者的CD4，CD8，叉头盒P3（FOXP3），CD68，CD163，程序性细胞死亡蛋白1（PD-1）及其配体（PD-L1）在纯DCIS和DCIS-Mi中的表达，通过免疫组织化学确定。DFS，临床病理参数，免疫标记和生物标记表达与Mi的存在相关。在198例DCIS病例中，有12例与Mi有关。DCIS-Mi与同侧浸润复发显着相关（p  = 0.032）。Kaplan-Meier分析显示，DCIS-Mi对同侧浸润性复发的DFS较差（p  = 0.011），多因素Cox回归分析证实了这一点（95％CI 1.181–9.010，HR = 3.262，p = 0.023）。DCIS-Mi与CD4（p  = 0.037），FOXP3（p  = 0.037），CD163（p  = 0.01）和PD-L1（p  = 0.015）阳性的更高免疫浸润密度有关。这项研究表明，DCIS-Mi与高密度的免疫浸润和预期的同侧浸润复发相关。