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.