ABSTRACT
Purpose@#Biliary tract cancers (BTCs) are rare and show a dismal prognosis with limited treatment options. To improve our understanding of these heterogeneous tumors and develop effective therapeutic agents, suitable preclinical models reflecting diverse tumor characteristics are needed. We established and characterized new patient-derived cancer cell cultures and patient-derived xenograft (PDX) models using malignant ascites from five patients with BTC. @*Materials and Methods@#Five patient-derived cancer cell cultures and three PDX models derived from malignant ascites of five patients with BTC, AMCBTC-01, -02, -03, -04, and -05, were established. To characterize the models histogenetically and confirm whether characteristics of the primary tumor were maintained, targeted sequencing and histopathological comparison between primary tissue and xenograft tumors were performed. @*Results@#From malignant ascites of five BTC patients, five patient-derived cancer cell cultures (100% success rate), and three PDXs (60% success rate) were established. The morphological characteristics of three primary xenograft tumors were compared with those of matched primary tumors, and they displayed a similar morphology. The mutated genes in samples (models, primary tumor tissue, or both) from more than one patient were TP53 (n=2), KRAS (n=2), and STK11 (n=2). Overall, the pattern of commonly mutated genes in BTC cell cultures was different from that in commercially available BTC cell lines. @*Conclusion@#We successfully established the patient-derived cancer cell cultures and xenograft models derived from malignant ascites in BTC patients. These models accompanied by different genetic characteristics from commercially available models will help better understand BTC biology.
ABSTRACT
Background/Aims@#Food retention, which is a characteristic observed in patients with achalasia, can interfere with peroral endoscopic myotomy (POEM).However, there is no established guideline for esophageal preparation for POEM. A previous study has shown that drinking warmwater may reduce the lower esophageal sphincter pressure in patients with achalasia. This study aims to evaluate the possibility ofproper preparation of POEM by instructing the patient to drink warm water. @*Methods@#The warm water preparation was performed in 29 patients with achalasia who underwent POEM. The patients drank 1 L of warm water (60 o C) the night before POEM. We evaluated the esophageal clearness and determined the preparation quality. Twenty-nine patients were prospectively recruited and compared to control group. The control cohort comprised achalasia patients whoseendoscopic image was available from the achalasia database of our institution. A 1:2 propensity score-matched control cohort was established from the database of achalasia subjects (n = 155) to compare the outcome of the preparation. @*Results@#In the warm water preparation group, only 1 patient (3.4%) had some solid retention, but it did not interfere with the POEM procedure. The grade of clearness (P = 0.016) and quality of preparation (P < 0.001) were significantly better in the warm water preparation group than in the matched control group. There was no any adverse event at all related to warm water preparation protocol. @*Conclusions@#Drinking warm water dramatically reduces esophageal food retention and significantly improves the quality of esophageal preparation.This simple protocol is quite useful, safe, and cost-effective in the preparation of achalasia patients for POEM.