P53 Immunolabeling in EUS‐FNA Biopsy Can Predict Low Resection Rate and Early Recurrence in Resectable or Borderline Resectable Pancreatic Cancer Treated with Neoadjuvant Therapy

PurposeKRAS, P16, TP53, and SMAD4/DPC4 mutations are common in pancreatic ductal adenocarcinoma (PDAC). The study aimed to evaluate the association between gene mutations in pre-treatment endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) samples and clinical outcomes of patients with PDAC. MethodsThere were 43 patients with resectable (R) PDAC and 41 patients with borderline resectable (BR) PDAC. CDKN2A/p16, TP53, and SMAD4/DPC4 were evaluated through immunohistochemistry (IHC) of pretreatment EUS-FNA (n = 84) and resected specimens (n = 71). All patients received neoadjuvant therapy. ResultsIHC of EUS-FNA specimens revealed p16 loss in 61 (73%), abnormal p53 in 61 (73%), and Smad4 loss in 38 (45%) patients. Abnormal p53 was associated with a lower resection rate (p = .017). Abnormal p53 and Smad4 loss were associated with recurrence within 6 months post-pancreatectomy (p = .03, p = .03, respectively). Univariate Cox regression analysis was conducted to reveal that abnormal p53 (p = .07), p16 loss and abnormal p53 (p = .04), and Smad4 and p16 loss (p = .03) were associated with poor prognosis. ConclusionsPre-treatment abnormal labeling of p53 in EUS-FNA specimen was associated with a lower resection rate and an early recurrence in R or BR PDAC cases.