Conclusions:
- In our patient cohort, immune cells in the TME of liver metastatic sites were less abundant.
- The paucity of immune cells suggests breast cancer metastases to the liver harbors a less immunogenic niche.
- Increased TMB in all metastatic sites uncovers the heterogeneity among different tumor sites.
- Immunosuppressive cells of myeloid and lymphoid origin prevent further immune cell infiltration in the TME.
- Lack of PD-L1 expression among liver metastatic sites suggests another possible mechanism explaining the lack of response to ICIs in certain patients.
- In our patient cohort, immune cells in the TME of liver metastatic sites were less abundant.
- The paucity of immune cells suggests breast cancer metastases to the liver harbors a less immunogenic niche.
- Increased TMB in all metastatic sites uncovers the heterogeneity among different tumor sites.
- Immunosuppressive cells of myeloid and lymphoid origin prevent further immune cell infiltration in the TME.
- Lack of PD-L1 expression among liver metastatic sites suggests another possible mechanism explaining the lack of response to ICIs in certain patients.