Granulocytic immune infiltrates are essential for the efficient formation of breast cancer liver metastases

Breast Cancer Research

Table 2 N2-polarized neutrophils are recruited at the invasive front of breast liver metastases over time

		D7
Location	0 < metastatic lesion area/liver area (%) <1.79
	% N2 neutrophils ^a	Error	P value
Distal	60.84	+/− 9.39
Invasive front	90.19	+/− 6.04	<0.00001
		D14
Location	Low metastatic burden
	2.16 < metastatic lesion area/liver area (%) <4.19
	% N2 neutrophils ^a	Error	P value
Distal	79.58	+/− 5.93
Invasive front	94.92	+/− 3.56	<0.0001
		D14
Location	High metastatic burden
	13.62 < metastatic lesion area/liver area (%) <54.12
	% N2 neutrophils ^a	Error	P value
Distal	88.21	+/− 3.53
Invasive front	93.63	+/− 2.80	0.003

^aOCT-embedded sections from liver metastases were collected either 7 days (D7) or 14 days (D14) following splenic injection of breast cancer cells and subjected to immunohistofluorescence staining with anti-Ly-6G (cyan), MMP9 (red) or Cd11b (green) antibodies. The percentage of pro-tumorigenic (N2)-polarized neutrophils (Cd11b⁺/Ly-6G⁺/MMP9⁺) out of the total number of neutrophils (Cd11b⁺/Ly-6G⁺) was assessed either at the invasive front of the metastatic lesions or in regions distal to the metastases (distal). Representative images can be found in Additional files 3 and 4.

ISSN: 1465-542X