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.

Gastric leptomeningeal carcinomatosis: Multi-center retrospective analysis of 54 cases

AIM: To identify the clinical features and outcomes of infrequently reported leptomeningeal carcinomatosis (LMC) of gastric cancer.METHODS: We analyzed 54 cases of cytologically confirmed gastric LMC at four institutions from 1994 to 2007.RESULTS: The male-to-female ratio was 32:22, and the patients ranged in age from 28 to 78 years (median,48.5 years). The majority of patients had advanced disease at initial diagnosis of gastric cancer. The clini-cal or pathologic tumor, node and metastasis stage ofthe primary gastric cancer wasin 38 patients (70%).The median interval from diagnosis of the primarymalignancy to the diagnosis of LMC was 6.3 mo, rang-ing between 0 and 73.1 mo. Of the initial endoscopic f indings for the 45 available patients, 23 (51%) of the patients were Bormann typeand 15 (33%) patientswere Bormann type. Pathologically, 94% of cases proved to be poorly differentiated adenocarcinomas. Signet ring cell component was also observed in 40% of patients. Headache (85%) and nausea/vomiting (58%) were the most common presenting symptoms of LMC. A gadolinium-enhanced magnetic resonance imaging was conducted in 51 patients. Leptomeningeal enhancement was noted in 45 cases (82%). Intrathecal (IT) chemotherapy was administered to 36 patients-primarily methotrexate alone (61%), but also in combi-nation with hydrocortisone/± Ara-C (39%). The median number of IT treatments was 7 (range, 1-18). Concomitant radiotherapy was administered to 18 patients, and concomitant chemotherapy to seven patients. Sev-enteen patients (46%) achieved cytological negative conversion. Median overall survival duration from the diagnosis of LMC was 6.7 wk (95% CI: 4.3-9.1 wk). In the univariate analysis of survival duration, hemoglobin, IT chemotherapy, and cytological negative conversion showed superior survival duration (P = 0.038, P = 0.010, and P = 0.002, respectively). However, in our multivariate analysis, only cytological negative conversion was predictive of relatively longer survival duration (3.6, 6.7 and 14.6 wk, P = 0.030, RR: 0.415, 95% CI: 0.188-0.918).CONCLUSION: Although these patients had a fatal clinical course, cytologic negative conversion by IT chemotherapy may improve survival.

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.