Ggesting EMT [114]. A report of two EML4-ALK+ NSCLC instances below TKI further highlighted the predictive value of CTC liquid biopsy, which permitted to differentiate the two sufferers in their clinical course: re-emergence of CTCs through follow-up correlated with disease progression [115]. Ultimately, though CTC count can have prognostic value in ALK+ NSCLC, CTCs can also be made use of to shed light on drug resistance mechanisms: an L1196M mutation (Table two) was foundCancers 2021, 13,8 ofby CTC gene sequencing inside the peripheral blood of sufferers with acquired resistance to crizotinib [116]. Pailler et al. detected drug-resistant mutations in CTCs from 17 sufferers progressed on crizotinib (n = 14) and lorlatinib (n = 3). Interestingly, one particular lorlatinib-resistant patient showed two distinct compound ALK mutations in distinct CTCs, sharing the refractory G1202R substitution [117].Table 2. ALK mutational information obtained by liquid biopsy in numerous ALK+tumors. Study Gambacorti-Passerini et al. Wang et al. Zhang et al. Pailler et al. Aggarwal et al. Ref. [54] [89] [116] [117] [100] Tumor ALCL NSCLC NSCLC NSCLC NSCLC Material RNAMethod PCR capture PCR PCR capture, PCRVariant(s) I1171N, M1328I L1152R, I1171T, L1196M L1196M G1202R+F1174C, G1202R+T1151M I1171S/T, F1174L, L1196Q, G1202R, G1123S I1171N, F1174C/L, L1196M, G1202R, D1203N, E1210K, I1171N+G1202R G1269A, S1206F, G1202R; others at low freq. F1174C/L, G1269A G1202R, L1196M, I1171N/T/S, V1180L, G1269A, D1203N, G1202R+L1196M, D1203N+I1171N; other folks at low freq. G1269A, G1202R, F1174X , L1196M, I1171X ; others at low freq. L1196M+G1202R G1269A, G1202R G1202R L1196M, G1202R F1174L, R1275Q H1030P, F1174L, L1196M Disperse Red 1 Autophagy F1174L F1174C F1174L/C, G1128A, F1245VTherapy Crizotinib Crizotinib Crizotinib Lorlatinib n.r. Ceritinib, Alectinib, Brigatinib Crizotinib or Crizotinib + 2nd gen. TKI CrizotinibctDNA CTC CTC ctDNADagogo-Jack et al.[103]NSCLCctDNAcaptureHorn et al. Dietz et al.[104] [118]NSCLC NSCLCctDNA ctDNAcapture captureDagogo-Jack et al.[107]NSCLCctDNAcaptureMultiple sequential TKIsShaw et al. Sharma et al. S chez-Herrero et al. K ig et al. Brinkmann et al. Combaret et al. Chicard et al. Cimmino et al. cis-4-Hydroxy-L-proline In Vitro Carneiro et al. Siravegna et al.[108] [119] [120] [121] [122] [123] [124] [125] [126] [127]NSCLC NSCLC NSCLC NSCLC NSCLC NB NB NB PCa CRCctDNA ctDNA ctDNA ctDNA exosomes ctDNA ctDNA ctDNA ctDNA ctDNAcapture PCR PCR n.r. PCR PCR capture capture capture PCRVarious TKIs Brigatinib Crizotinib and Ceritinib Ceritinib n.r. Pre-treatment Pre-treatment, chemo Pre-treatment Pre-treatment Entrectinibtotal RNA obtained from peripheral blood mononuclear cells. X indicates numerous possible substitutions; NB, neuroblastoma; PCa, prostate carcinoma; CRC, colorectal cancer; n.r., not reported.3.two.two. Circulating DNA ctDNA detection in earlier studies relied on the use of allele-specific PCR [27]. On the other hand, the technique suffered from many limitations like the limit of detection and essential prior knowledge from the specific mutations. Within this regard, gene fusions are extra effortlessly assessed by PCR than single nucleotide variants, as they create fully newCancers 2021, 13,9 ofsequences which are not present in regular tissue. Anyway, novel NGS-based tactics happen to be created that offer higher sensitivity and throughput for ctDNA variant detection [22,32,33,107,108]. ALK-Positive Individuals in Massive Cohorts Various big research evaluating the diagnostic and prognostic use of ctDNA in NSCLC, that integrated some ALK+ sufferers, are ava.
