The Study Of The Application Of Endoscopic Ultrasound-guided Fine-needle Biopsy In The Individualized Treatment Of Pancreatic Ductal Adenocarcinoma

Background and Objective: Pancreatic ductal adenocarcinoma(PDAC)is one of the most lethal malignant tumors in the world,with a poor 5-year survival rate of 9%.Since 80%-85% of PDAC patients are diagnosed at an advanced stage and lose the opportunity for surgery,chemotherapy is still the main treatment for most PDAC patients.The formulation of chemotherapy regimens should consider not only the pathological type of the tumor,but also the heterogeneity of the tumor,which leads to different sensitivities of patients to different drugs.Therefore,individualized treatment is an important treatment strategy for PDAC.To achieve individualized treatment,we must first obtain tumor tissue samples.Since only 15%-20% of patients have the opportunity to receive surgical treatment,endoscopic ultrasound-guided fine-needle biopsy(EUS-FNB)technique,which can be applied in all clinical stages of PDAC,has become an important means to obtain tumor samples and realize individualized treatment.However,can specimens obtained by EUS-FNB be used to culture PDAC primary cells to guide individualized therapy? At present,there are few studies at home and abroad in this field.Meanwhile,it is not clear about the optimal needle type,gauge(G),and puncture technique in the process of obtaining specimens,as well as the amount of specimen required to successfully culture primary cells,and the accuracy of primary cell drug screening results.Therefore,the aim of this study is to prospectively explore the puncture technique which can obtain more highquality specimens of pancreatic solid lesions,and evaluate the amount of specimens required to successfully culture PDAC primary cells.Then,patient-derived primary cells were used to screen sensitive chemotherapy drugs.Simultaneously,in order to evaluate the feasibility of primary cells from EUS-FNB samples for individualized treatment,we compared the differences in the culture success rate and culture time,as well as analyzed the consistency and accuracy of drug screening results between the primary cells derived from EUS-FNB specimens and surgical specimens.We hope that with this approach,the drug screening results can guide the formulation or adjustment of chemotherapy regiments for PDAC patients in a short time,so as to improve the chemotherapy effect of patients.Methods:(1)To explore a more efficacy method to obtain tissue specimens of pancreatic solid lesions: A prospective,single-blind,randomized,self-controlled,crossover study was designed.Patients with pancreatic solid lesions were screened according to the inclusion and exclusion criteria.The differences in specimen adequacy,macroscopic visible core(MVC)length,blood contamination,diagnostic yields,and adverse events between EUS-FNB with dry suction technique(DST)and EUS-FNB with modified wet suction technique(MWEST)in pancreatic solid lesions had been compared.(2)To explore the minimum amount of specimens required to successfully culture patient-derived primary cells(PDC): A prospective,double-blind,randomized,self-controlled,crossover study was designed.Patients with PDAC were screened according to the inclusion and exclusion criteria.We compared the differences in the success rate and culture time of primary cells obtained by EUS-FNB with MWEST in PDAC between 1 needle pass and 2 needle passes,and analyzed the minimum amount of specimens required for successful primary cell culture.(3)To explore the clinical application value of EUS-FNB with MWEST-PDC-drug screening system in individualized treatment of PDAC: The EUS-FNB specimens and surgical specimens from PDAC patients were collected prospectively.Immunofluorescence(IF)technique was used to verify whether the primary cells were PDAC cells.The differences in culture success rate and culture time of primary cells between the two groups were compared,and the consistency of drug screening results between the two groups as well as between the lab results and clinical efficacy had been analyzed.Results:(1)To explore a more efficacy method to obtain tissue specimens of pancreatic solid lesions: Between January 2019 and September 2019,a total of 50 patients with pancreatic solid lesions were screened and included in the final analysis.MWEST was significantly better than DST in specimen adequacy(per lesion analysis: P=0.026)and MVC length(P=0.036).Comparing to DST,MWEST was inferior in blood contamination(cytology: P=0.021;histology: P=0.042).At the aspect of diagnostic yields,MWEST was comparable with DST in overall analysis(P=0.084)and cytological analysis(P=0.121),however,better than DST in histological analysis(P=0.014).No serious adverse events related to EUS-FNB occurred in all patients.(2)To explore the minimum amount of EUS-FNB specimens required to successfully culture primary cells: Between January 2021 and November 2021,a total of 43 patients with PDAC were screened and included in the final analysis.In the comparison of the success rate of primary cells P0 and P3 culture(P0: P=0.820;P3: P=0.506)and the P1(P=0.547),P2(P=0.149),P3(P=0.549)culture time,there was no significant difference between the 1 needle group and the 2 needle group.The receiver operator characteristic(ROC)curve of MVC length required for successful culture of primary cells P0 showed that when MVC≥2.5cm,area under the curve(AUC)was 0.764(95% CI: 0.662-0.865,P<0.001),and the sensitivity and specificity of successful culture were 66.7% and69%,respectively.No serious adverse events related to EUS-FNB occurred in all patients.(3)To explore the clinical application value of EUS-FNB with MWEST-PDC-drug screening system in individualized treatment of PDAC: Between January 2021 and November 2021,43 and 23 patients with PDAC who respectively underwent EUS-FNB and surgery were screened and included in the final analysis.IF results showed that the primary cells were PDAC cells.There was no significant difference between the EUS-FNB group and the surgical group in the culture success rate of primary cell P0(66.28% vs.73.91%,P=0.486).The culture success rate of primary cell P3 in EUS-FNB group was 39.53%,which was significantly different from that in surgical group(66.22%)(P=0.028).The culture time of primary cell P1 was significantly shorter in the surgical group than that in the EUS-FNB group(P=0.002).However,there was no significant difference between the two groups in the culture time of P2(P=0.97)and P3(P=0.081).Among the 3 patients who had drug screening results of both groups,the intraclass correlation coefficient(ICC)of drug screening results between EUS-FNB 1 needle group and surgical group was 0.822,and the ICC of drug screening results between EUS-FNB 2needle group and surgical group was 0.932,all of them had good consistency.Among the 5 patients with both primary cell drug screening results and clinical treatment data,the drug screening results were consistent with the clinical treatment effect of the patients.Conclusions:(1)Compared to EUS-FNB with DST,EUS-FNB with MWEST can improve the specimen quality and histological diagnostic yield in pancreatic solid lesions.(2)EUS-FNB with MWEST(using a 22 G Procore needle)for 1needle puncture can have a good success rate of PDC culture,which was comparable to that of 2 needle puncture.When the MVC length is ≥ 2.5cm,the culture of primary cells of PDAC is prone to success.EUS-FNB with MWEST has the potential to be the best method to obtain primary cell materials.(3)The PDC generated from EUS-FNB specimens can obtain individualized sensitive drug screening results in a relatively short period of time,and the results are consistent with the PDC drug screening results generated from surgical specimens and the clinical effect of patients.EUSFNB with MWEST-PDC-drug screening system has a good application prospect in the individualized treatment of PDAC.