Efficacy of chemotherapy containing bevacizumab in patients with metastatic colorectal cancer according to programmed cell death ligand 1

BACKGROUND Bevacizumab,an anti-vascular endothelial growth factor(VEGF)monoclonal antibody,inhibits angiogenesis and reduces tumor growth.Serum VEGF-C,lactate dehydrogenase,and inflammatory markers have been reported as predictive markers related to bevacizumab treatment.Programmed cell death ligand 1(PD-L1)could act upon VEGF receptor 2 to induce cancer cell angiogenesis and metastasis.AIM To investigate the efficacy of bevacizumab-containing chemotherapy in patients with metastatic colorectal cancer(CRC)according to the expression of PD-L1.METHODS This analysis included CRC patients who received bevacizumab plus FOLFOX or FOLFIRI as first-line therapy between June 24,2014 and February 28,2022,at Samsung Medical Center(Seoul,South Korea).Analysis of patient data included evaluation of PD-L1 expression by the combined positive score(CPS).We analyzed the efficacy of bevacizumab according to PD-L1 expression status in patients with CRC.RESULTS A total of 124 patients was included in this analysis.Almost all patients were treated with bevacizumab plus FOLFIRI or FOLFOX as the first-line chemotherapy.While 77%of patients received FOLFOX,23%received FOLFIRI as backbone first-line chemotherapy.The numbers of patients with a PD-L1 CPS of 1 or more,5 or more,or 10 or more were 105(85%),64(52%),and 32(26%),respectively.The results showed no significant difference in progression-free survival(PFS)and overall survival(OS)with bevacizumab treatment between patients with PDL1 CPS less than 1 and those with PD-L1 CPS of 1 or more(PD-L1<1%vs PD-L1≥1%;PFS:P=0.93,OS:P=0.33),between patients with PD-L1 CPS less than 5 and of 5 or more(PD-L1<5%vs PD-L1≥5%;PFS:P=0.409,OS:P=0.746),and between patients with PD-L1 CPS less than 10 and of 10 or more(PD-L1<10%vs PD-L1≥10%;PFS:P=0.529,OS:P=0.568).CONCLUSION Chemotherapy containing bevacizumab can be considered as first-line therapy in metastatic CRC irrespective of PD-L1 expression.

Comprehensive molecular analysis to predict the efficacy ofchemotherapy containing bevacizumab in patients with metastaticcolorectal cancer

Background:Although bevacizumab is an important treatment for metastatic colorectal cancer(CRC),not allpatients with CRC benefit from it;in unselected patient populations,only modest survival benefits have been reported.Methods:We evaluated clinical outcomes in 110 patients using comprehensive molecular characterization to identifybiomarkers for a response to bevacizumab-containing treatment.The molecular analysis comprised whole-exomesequencing,ribonucleic acid sequencing,and a methylation array on patient tissues.Results:Genomic and molecularcharacterization was successfully conducted in 103 patients.Six of 103 CRC samples were hypermutated,and none ofthe non-hypermutant tumors were microsatellite unstable.Among those 103 patients,89 had adenocarcinoma(ADC),15 were diagnosed with mucinous ADC,and six had signet-ring cell carcinoma(SRCC).Consensus molecular subtype(CMS)2 was unique to ADC.Of the four SRCCs,two were CMS1,one was CMS4,and the other was CMS3.APCmutation status was a significantly enriched factor in responders to bevacizumab treatment.Fibroblast growth factorreceptor(FGFR)1/2 signaling was upregulated in non-responders,whereas cell cycle,transfer ribonucleic acidprocessing,nucleotide excision repair,and oxidative phosphorylation pathways were enriched in responders.Inaddition,IGF1 was differentially expressed in non-responders(log2 fold change=−1.43,p=4.11×10^(−5),falsediscovery rate=0.098),and FLT1 was highly methylated in non-responders(p=7.55×10^(−3)).When the molecularpathways were reanalyzed separately according to the backbone chemotherapy(FOLFOX vs.FOLFIRI),thesignificance of the molecular pathways varied according to the backbone chemotherapy.Conclusions:This studysought a subset of CRC patients with a distinct clinical response to chemotherapy containing bevacizumab.Ourresults need to be validated in a large group of homogenous patient cohort and examined according to the differentchemotherapy backbones to create personalized therapeutic opportunities in CRC.

Two Gnaphosid Spiders (Araneae: Gnaphosidae) New to Korean Spider Fauna

Drassyllus yaginumai Kamura, 1987 and Zelotes tortuosus Kamura, 1987 belonging to Gnaphosidae were captured by pitfall trap in maize and soybean fields during the survey of arthropod fauna of agricultural ecosystem in Korea. Present work describes these 2 species with illustrations of taxonomic characters.