1613 Adenosquamous Carcinoma of the Pancreas: A Clinicopathologic Analysis of 33 Cases

Document Type

Conference Proceeding

Publication Date

3-24-2025

Publication Title

Lab Invest

Keywords

adenosquamous carcinoma, adenosquamous carcinoma of the pancreas, adult, aged, aggression, cancer staging, clinical article, cohort analysis, conference abstract, diagnosis, drug therapy, female, fine needle aspiration biopsy, follow up, high throughput sequencing, human, human tissue, male, median survival time, pancreatic ductal carcinoma, special situation for pharmacovigilance, squamous cell carcinoma, tumor volume

Abstract

Disclosures: Kerem Ozcan: None; Brian Theisen: None; Gazala Khan: None; Qing Chang: None; Beena Ahsan: None Background: Adenosquamous carcinoma (ASC) of the pancreas is a rare subtype of cancer. Clinicopathologic and molecular data on this entity remains limited. Here we identify and describe clinical and molecular features on a population of ASC. Design: We identified 33 cases of ASC and performed a detailed analysis of clinicopathologic features and molecular results. ASC cases were compared with a cohort of 70 consecutive conventional pancreatic ductal adenocarcinoma (PDAC) cases. Next Generation Sequencing assay (NGS) was performed on a subset of ASC. Results: Clinicopathologic features of pancreatic ASC and PDAC are summarized in Table. There were slightly more male patients than female patients diagnosed with ASC. Compared to PDAC, ASC patients were older (median: 74, range 54-81, p<.0005), with larger tumor size (median: 4.3 cm, range 1-8.2, p<.00001), higher T stage (T3 or T4: 63% vs 23%, p<.001), and higher clinical stage (Stage III or IV: 60% vs 28.6%, p<.0003). However, ASC did not show higher rate of nodal metastases when compared with PDAC (60.9% vs 54.4%). ASC of the pancreas was more frequently located in the body/tail (51.6% vs 18.6%, p<.01). Radiologic findings of all available patients showed hypodense lesions, with 21% significant for central necrosis. Squamous differentiation was detected on fine needle aspiration for 12 patients and reported as "(adeno)carcinoma with squamous differentiation". In all cases, CK 5/6, p40 or p63 were used to highlight the squamous component. Squamous cell carcinoma was the predominant component in one case. NGS data were available for 13 cases. Most commonly encountered mutations included KRAS (69.2%), TP53 (53.9%), CDKN2A (30.8%), SMAD4 (23.1%), KMT (23.1%) and PIK3CA (15.4%). On follow up, ASC had significantly worse prognosis when compared to PDAC. 27 patients died of disease with a median survival of 6 months (range: 0-39). Only 6 patients were alive with disease with a median follow up of 15.5 months (range: 1--28 months)(Figure 1). Clinicopathologic features of adenosquamous carcinomas of the pancreas and pancreatic ductal adenocarcinomas [Formula presented] [Formula presented] Conclusions: Adenosquamous carcinoma of the pancreas is an aggressive malignancy with an even worse prognosis than PDAC. It presents as a larger mass, in older patients with higher T and clinical stages and has a higher propensity for body/tail. Although an arbitrary 30% cut-off is typically used to diagnose ASC, it is also known that presence of any squamous component is associated with a worse prognosis which aligns with our findings that ASC group diagnosed on FNA having similar behavior with the rest of ASC cohort.

Volume

105

Issue

3

Find It @ Sladen

Share

COinS