Methodological Design Of Circulating Tumor DNA To Predict Chemotherapy Efficacy In Neuroendocrine Neoplasms

Objective:Metastatic neuroendocrine neoplasms(mNENs)is a relatively rare tumor.Despite the availability of drugs,there are still few options,requiring precise monitoring and selection.Currently,evaluation of outcomes in patients with neuroendocrine tumors relies on imaging(e.g.response evaluation criteria in solid tumors[RECIST]1.1),combined with tumor markers(e.g.chromogranin A[CgA],Neuron-specific enolace[NSE],progastrin-releasing peptide(ProGRP)).However,imaging examination is not easy to detect small and hidden metastatic lesions,and traditional tumor markers such as CgA,NSE and ProGRP lack sensitivity and specificity.The purpose of this study was to design a methodology to explore a novel tumor marker circulating tumor DNA(ctDNA)for monitoring the efficacy of chemotherapy in patients with metastatic neuroendocrine tumors.Content:In this study,primary or metastatic lesion tissue,blood samples were collected from patients with metastatic neuroendocrine tumors receiving chemotherapy based on the S-1 and temozolomide regimen,prior to chemotherapy,and during treatment.Whole exon sequencing(WES)was performed on tumor tissue,and ctDNA testing was performed on blood samples.By analyzing mutations during the treatment process,and collecting imaging monitoring results during the treatment process,the feasibility of using ctDNA to monitor chemotherapy in patients with metastatic neuroendocrine tumors was explored.Method:Collect tumor tissue from patients with metastatic neuroendocrine tumors at their primary or metastatic sites for full exon sequencing,accurately identify single nucleotide variations(SNV)sites,and develop personalized kits for each patient based on the specific SNV.Collect blood samples from patients before using chemotherapy drugsbaseline blood.During the treatment process,collect blood samples from patients every 2 or 3 cycles,extract cfDNA from plasma,and conduct targeted enrichment sequencing(Raceseq)and low depth sequencing technology after the establishment of the database.Through bioinformatics analysis,dynamically track mutations at each blood collection point.The sensitivity and specificity of ctDNA monitoring for chemotherapy in patients with metastatic neuroendocrine tumors were analyzed based on the clinical information of the patients and the results of imaging evaluation according to the RECIST 1.1 standard.Objective: Owing to the scarcity of reported cases of primary neuroendocrine breast carcinomas(NEBCs),this study was aimed to explore the prognostic factors for NEBCs in Chinese and US cohorts.Contents: In this multicenter retrospective study,tiie prognostic factors for patients with primary NEBCs who underwent surgery and had a pathologically confirmed diagnosis of neuroendocrine carcinoma in China and the United States were examined.The endpoints were disease-free survival(DFS)and overall survival(OS).Methods: Data of patients who visited the Cancer Hospital Chinese Academy of Medical Sciences between 2000 mid 2018 were retrospectively collected,and the information on the survival status of patients was obtained by telephone follow-up.Data of patients in Beijing Cancer Hospital were collected from the database,based on a published article and the National Cancer Institute database(The Surveillance,Epidemiology,and End Results,SEER)obtained data on primary NEBCs patients in Beijing Cancer Hospital from 2000 to 2018,Beijing Hospitals from 2008 to 2017 and in the US from 2010 to2015.Chi-square test,Fisher’s precision probability test and rank-sum test were used for statistical analysis,Cox regression model was established for survival mialysis,and random effects model was used for combined analysis.Results: A total of 51 Chinese patients and 98 US patients were included.In the Chinese cohort,tumor grade and Ki-67 levels were prognostic factors for DFS in univariate analysis(hazard ratio [HR] = 5.11 [1.67-15.60],P = 0.004;HR = 57.70 [6.36-523.40],P < 0.001,respectively)and multivariate analysis(HR = 100.52 [1.33-7570.21],P = 0.037;HR = 31.47 [1.05-945.82],P = 0.047,respectively).In the US cohort,age was an important prognostic factor for OS in univariate analysis(HR = 1.09 [1.04-1.15],P = 0.001).The random effects model for the combined cohorts revealed age and positive expression of estrogen receptor(ER)as potential prognostic factors for OS(HR = 1.08[1.01-1.14],P= 0.015;HR= 0.10 [0.02-0.44],P= 0.003,respectively).Conclusions: Tumor grade and Ki-67 levels are important prognostic factors for DFS of patients with primary NEBCs.Age and ER status are important prognostic factors for OS of patients with primary NEBCs.