Recombinant humanized anti-VEGF monoclonal antibody(Stainwei Biotech)

Carcinoembryonic antigen (CEA) is the most widely used tumor marker in metastatic colorectal cancer (mCRC). However, its potential as a predictive marker of progression in mCRC during systemic chemotherapy, particularly in patients receiving monoclonal antibodies as a combination therapy, has remained of interest. Herein, we investigated whether CEA changes could predict disease progression and clinical outcomes in patients with mCRC cotreated with systemic chemotherapy and/or biologic agents. A total of 1261 patients with mCRC undergoing a first-line systemic treatment were included in this retrospective study. We analyzed the optimal cut-off value for CEA changes to predict progression at the first response evaluation by the treatment arm (chemotherapy alone, chemotherapy plus anti-vascular endothelial growth factor (VEGF) monoclonal antibody [mAb], and chemotherapy plus anti-epidermal growth factor receptor [EGFR] mAb). These cut-off values were then used to predict overall survival (OS) and progression-free survival (PFS). When stratified by their treatment arm, 891 (70.6%), 266 (21.0%), and 104 (8.2%) of the study patients were included in the chemotherapy alone-, anti-VEGF mAb, and anti-EGFR mAb groups, respectively. The optimal CEA cut-off values were 16.5% and 38.9% increase in the whole cohort and anti-EGFR mAb group, respectively, and these values showed high sensitivity and specificity for predicting disease progression. The patients in the entire population and anti-EGFR mAb group with CEA changes below these cut-off values showed significantly better OS and PFS outcomes compared those whose changes were above cut-off values. Among the patients with mCRC treated with anti-VEGF mAb, no associations were found between OS or PFS outcomes and CEA changes. CEA is potentially a good surrogate marker for predicting disease progression and survival outcomes in patients with mCRC receiving first-line systemic chemotherapy alone or chemotherapy with anti-EGFR mAb, whereas it is less effective in those treated with anti-VEGF mAb.

Chemotherapy combined with anti-EGFR or anti-VEGF monoclonal antibodies (mAb) is widely used to treat patients with metastatic colorectal cancer (mCRC). Here, we investigated the effects of these antibodies on T-cell infiltration and T-cell receptor (TCR) repertoire variation in CRC liver metastases.

Ten patients with mCRC received chemotherapy in combination with anti-EGFR (n=6) or anti-VEGF (n=4) mAb. T-cell infiltration was examined for CD3 and CD8 by carrying out immunohistochemistry on biopsy or surgical specimens from liver metastases before and after treatment. TCR repertoire analysis was carried out on specimens with post-treatment CD3⁺ T-cell infiltration.

T-cell infiltrations were approximately 83% (5/6) and 50% (2/4), following treatment with anti-EGFR or anti-VEGF mAb, respectively. TCR repertoire analysis revealed higher clonality and lower diversity of TCR alpha and beta (TRA and TRB) in the anti-VEGF mAb group than that in the anti-EGFR group mAb. Furthermore, the percentage of the common TCR clones between infiltrating T cells and T cells in peripheral blood was significantly lower in the anti-VEGF mAb group compared to that in the anti-EGFR mAb group.

The population of T cells infiltrating liver metastases in the anti-VEGF mAb group differed from that in the anti-EGFR mAb group.