A prospective comparative trial to determine the optimal number of EUS-guided fineneedle passes for successful organoid creation in pancreatic ductal adenocarcinoma.

Introduction: EUS-guided fine-needle organoid creation (EUS-FNO) from pancreatic cancer (PC) has been increasingly important for precision medicine. The cost for pancreatic organoid creation is substantial and close to 2000 USD/specimen in our institution, and the specimen has to be processed immediately after tissue acquisition so the more passes and specimens, the higher cost of organoid creation will incur. To date, no prospective comparison trial has answered how many needle passes of EUS-FNO needed for a successful organoid creation.

Methods: A prospective trial comparing the success rate of EUS-FNO between the first-pass (group A) versus combination of the first and the second-pass group (group B) was conducted at King Chulalongkorn Memorial Hospital, Thailand. Successful EUS-FNO in group B was defined as positive EUS-FNO from either 1 of 2 passes of EUS-FNO. Techniques for taking tissue from pancreatic cancer are the standard technique of EUS-guided fine needle biopsy (EUS-FNB) using a 20-gauge forward-bevel needle. Tissues from the first and second puncture were collected into separate test tubes that were frozen to control temperature and taken to a laboratory room for organoid culture. The success in pancreatic organoid creation is considered initial success when we could isolate organoids (P0). When organoids grow and are confluent in the Matrigel plate, we would pass the cell to grow in the other Matrigel plate and repeat the passing process until 5 passages of growth. Complete success is defined when we could establish pancreatic organoid lines for ≥5 passages of growth (P5). These processes were performed before standard EUS-FNB for histopathology. We then compared the success rate of pancreatic organoid establishment (P5) in cell culture between single versus two passages. McNemar's test was used for comparison between 2 groups.

Results: Fifty-two patients (33 females, 19 males) with PC underwent EUS-FNO during the period from September 15, 2020, to February 28, 2022, were recruited. Median age (range) was 64.0 (46-88) years. Median BMI (range) was 20.0 (14.6-30.8) kg/m². Tumors were located on the pancreatic head, neck, body, and tail of the pancreas at 57.7%, 7.7%, 25.0%, and 9.6%, respectively. Median size (range) of tumors was 41 (20-134) mm. Median CA19-9 level (range) was 187 units/mL (2.35-35,474). All initially generated pancreatic organoids (P0) could be successfully established (P5). The success rate of EUS-FNO from group A versus B was equally 78.8% (41 from 52 patients) versus 80.8% (42 from 52 patients) (P = 1.00).

Conclusion: Results from this current prospective trial showed that a single pass of EUS-FNO from a PC by using a 20-G forward-bevel needle provided a high success rate. Adding the second pass did not increase the success rate of EUS-FNO.