Distribution characteristics of immune infiltration and lymphovascular invasion in patients with breast cancer skin recurrence

To assess the distribution characteristics of immune infiltration and lymphovascular invasion in breast cancer skin recurrence patients.

We retrospectively analyzed the clinicopathological data of patients who underwent radical surgery for primary breast cancer and experienced skin recurrence between January 2001 and April 2019. Immune and lymphovascular biomarkers were quantified in primary breast cancers, skin lesions and visceral metastatic lesions. Differences in biomarkers distribution between matched tissues were statistically analyzed using the Wilcoxon signed-rank test and Kruskal–Wallis one-way ANOVA.

A total of 71 female breast cancer patients were reviewed in this study. Our study found that the expression levels of various lymphocyte immune markers in primary tumor specimens were higher than those in skin recurrences. The expression of CD8, CD57 and CD31 in primary breast cancer was higher than those in the skin. Compared to visceral metastatic lesions, D2-40 was highly expressed in the skin, while CD8 tended to decrease. In the skin specimens, the expression of CD8 (P < 0.001), FOXP3 (P = 0.006) and CD68 (P < 0.001) in the intratumoral area was higher, while the expression of CD57 (P < 0.001) was higher in the peritumoral area. Analyzing specimens from the same patient at different time points of skin progression, it was found that the expression of peritumoral CD4 decreased (P = 0.044) as the disease progressed. The low expression of D2-40 and CD163 in the skin lesions suggested a decrease in DFS.

The immune microenvironment of breast cancer skin recurrence may be in a state of suppression, and this suppression may intensify with disease progression. The pattern of skin recurrence may be more inclined toward lymphatic invasion. Our study provides new insights into the biological behaviors of this disease and its response to immunotherapy.