Abstract 96P
Background
This study is the first stage of prospective study of NGS-based testing of ctDNA in pts with various types of cancer and it's utility in routine oncological practice.
Methods
This prospective, single-center, sample collection study; pts with various cancers were included. For the detection of сtDNA, an assay based on a combination of targeted NGS and ddPCR was developed. Tumor somatic mutations were determined by target sequencing of DNA from FFPE tumor. Sequencing was performed using the small (96 amplicon) NGS panel covering regions of frequent cancer somatic mutations. Tumor-specific mutations were monitored in plasma samples. Mutations of plasma ctDNA were determined by ddPCR. The plasma sample was considered "positive” if the content of ctDNA was more than 0.5 copies of mutant DNA in ml plasma.
Results
The study comprised 599 pts, including pts with gastric cancer (62, 10%), pancreatic cancer (62, 10%), colorectal cancer (197, 33%), ovarian cancer (102, 17%), breast cancer (75, 12%), renal cancer (11, 2%), bladder cancer (6, 1%), and lung cancer (84, 14%). Distribution of cases by the stage was: I stage, 12%; II stage, 28%; III stage, 38%; and IV stage, 22%. Tumor-derived mutations were found in plasma with sensitivity of 60% for gastric cancer, 64% for pancreatic cancer, 89% for colorectal cancer, 74% for ovarian cancer, 73.6% for breast cancer, 36.4% for renal cancer, 66.6% for bladder cancer and 67.8% for lung cancer.
Conclusions
A robust and economical assay of ctDNA detection is sensitive (relative to the values founded in recent studies) for all examined types of tumors, except for renal cancer.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
This research is conducted under the auspices of the experimental governmental assignment of the Ministry of Health of the Russian Federation and coordinated by the FSBI “Centre for Strategic Planning and Management of Biomedical Health Risks” of the Ministry of Health of the Russian Federation.
Disclosure
All authors have declared no conflicts of interest.