1639P - Feasibility of tumor genomic sequencing on tissue obtained from endoscopic ultrasound in patients with pancreatic cancer

Background

Endoscopic fine needle biopsy (EUS-FNB) is an effective tissue sampling modality for diagnosing pancreatic cancer. Genomic sequencing is becoming essential with the emerging targeted therapies in pancreatic cancer. However, the feasibility of commercial comprehensive next-generation sequencing on tissue obtained from EUS-FNB is unknown. We aimed to examine the success rate of genomic sequencing utilizing tissue from EUS-FNB and correlate it with procedural characteristics.

Methods

We retrospectively reviewed a consecutive cohort of patients who underwent a diagnostic EUS-FNB during the workup of a pancreatic mass, over five years, at our institution. Genomic results, patient demographics, tumor characteristics, and technical aspects of the EUS-FNB were reviewed. The successful completion of sequencing was defined as the generation and reporting of DNA sequencing results.

Results

A total of 396 patients underwent endoscopic ultrasound with pancreatic mass biopsy as part of the routine diagnostic workup. Tumor sequencing from the pancreatic EUS-FNB was requested from 101 patient samples. The remaining samples had no sequencing performed, or sequencing was requested on pancreatectomy samples and/or metastatic sites. Of the 101 patients, sequencing was successful in 88 samples (87%). The median number of needle passes to obtain sufficient tissue for completion of sequencing was 3 (range 1-5). Tumor purity information was available in 71 samples; the average purity was 32% (range 20-90%). Genomic sequencing was unsuccessful in the remaining 13 samples (13%) due to inadequate tissue. The median number of needle passes for these patients was 2 (range 1-5). The cancer stage distribution for patients whose tumor sequencing was requested from pancreatic biopsies was the following: I (9%), II (10%), III (14%), and IV (67%). Genomic sequencing results will be presented at the meeting.

Conclusions

Comprehensive genomic sequencing of all stages of pancreatic cancer is feasible on EUS-FNB. Increasing the number of needle passes can increase the yield for tumor genomic sequencing. This is particularly important for locally advanced, unresectable pancreatic cancers without alternative sites for tissue sampling.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

V. Florou: Financial Interests, Personal, Advisory Role: Deciphera, Incyte. H.P. Soares: Financial Interests, Personal, Advisory Board: TerSera, Ipsen, AstraZeneca, Novartis, ITM. I. Garrido-Laguna: Financial Interests, Personal, Advisory Role: Sotio, Kanaph, Jazz, OncXerna. All other authors have declared no conflicts of interest.