ASCO 2021 | Impact of the tumor immune microenvironment on bevacizumab benefit in colon cancer

Katherine Pogue-Geile, PhD, NSABP Foundation/NRG Oncology, Pittsburgh, PA, discusses an examination of tumor immune microenvironment components and their associations with disease prognosis and bevacizumab benefit in the NRG Oncology/NSABP C-08 trial (NCT00096278) in patients with colon cancer. The C-08 trial showed that adding bevacizumab to FOLFOX did not add benefit to the overall population, but was beneficial in the patient subgroup with deficient mismatch repair (MMR). Over 1500 patients were assessed for various markers of T-cells, macrophages, and immune checkpoint proteins. The data showed that MMR status had a significant impact on the associations seen. PD-1, CD8, and CD8/PD-1 cells were associated with bevacizumab harm in the proficient MMR group, but benefit in those with deficient MMR. This interview took place at the American Society of Clinical Oncology (ASCO) 2021 Virtual Meeting.