scholarly journals Next Generation Sequencing of Tumor and Matched Plasma Samples: Identification of Somatic Variants in ctDNA From Ovarian Cancer Patients

2021 ◽  
Vol 11 ◽  
Author(s):  
Ana Barbosa ◽  
Pedro Pinto ◽  
Ana Peixoto ◽  
Joana Guerra ◽  
Manuela Pinheiro ◽  
...  

Genetic testing to detect somatic alterations is usually performed on formalin-fixed paraffin-embedded tumor samples. However, tumor molecular profiling through ctDNA analysis may be particularly interesting with the emergence of targeted therapies for ovarian cancer (OC), mainly when tumor is not available and biopsy is not viable, also allowing representation of multiple neoplastic subclones. Using a custom panel of 27 genes, next-generation sequencing (NGS) was performed on tumor and matched plasma samples from 96 OC patients, which were combined in two groups (treatment naive and post-treatment). Overall, at least one somatic variant present in the tumor sample was also detected in the matched plasma sample in 35.6% of the patients, a percentage that increased to 69.6% of the treatment naive patients and 83.3% of those with stage IV disease, showing the potential of ctDNA analysis as an alternative to identify somatic variants in these patients, namely those that have predictive value for targeted therapy. In fact, of the two treatment-naive patients with somatic BRCA1 variants identified in tumor samples, in one of them we detected in ctDNA a BRCA1 somatic variant that was present in the tumor with a VAF of 53%, but not in the one that had a VAF of 5.4%. We also showed that ctDNA analysis has a complementary role to molecular unraveling of inter- and intra-tumor heterogeneity, as exemplified by one patient diagnosed with bilateral OC in which different somatic variants from both tumors were detected in ctDNA. Interestingly, as these bilateral tumors shared a rare combination of two of the three variants identified in ctDNA, we could conclude that these morphologically different tumors were clonally related and not synchronous independent neoplasias. Moreover, in the post-treatment group of patients with plasma samples collected after surgery, those with detectable somatic variants had poor prognosis when compared with patients with no detectable somatic variants, highlighting the potential of ctDNA analysis to identify patients at higher risk of recurrence. Concluding, this study demonstrated that somatic variants can be detected in plasma samples of a significant proportion of OC patients, supporting the use of NGS-based ctDNA testing for noninvasive tumor molecular profiling and to stratify patients according to prognosis.

2019 ◽  
Vol 60 (10) ◽  
pp. 914 ◽  
Author(s):  
Yong Jae Lee ◽  
Dachan Kim ◽  
Hyun-Soo Kim ◽  
Kiyong Na ◽  
Jung-Yun Lee ◽  
...  

2020 ◽  
pp. 104063872096750
Author(s):  
Yasuyuki Momoi ◽  
Aya Matsuu

We used unbiased next-generation sequencing (NGS) to detect unknown viruses in cats. Serum or plasma samples were obtained from clinically ill cats with suspected acute viral infections. Nucleic acid was extracted from serum or plasma samples to construct a complementary DNA library for NGS. Comprehensive nucleotide sequencing analyses enabled detection of the genomes of various viruses, including the severe fever with thrombocytopenia syndrome virus, feline immunodeficiency virus, feline morbillivirus, parvovirus, and Torque teno felis virus. Our findings indicate that comprehensive nucleotide analyses of serum or plasma samples can be used to detect infections with unknown viruses in cats.


2015 ◽  
Vol 4 (11) ◽  
pp. e1030561 ◽  
Author(s):  
Miran Jang ◽  
Poh-Yin Yew ◽  
Kosei Hasegawa ◽  
Yuji Ikeda ◽  
Keiichi Fujiwara ◽  
...  

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