# Undifferentiated sarcomatoid carcinoma of the pancreas-a single-institution experience with 23 cases

## TL;DR

This study examines 23 rare cases of undifferentiated sarcomatoid carcinoma of the pancreas, finding poor survival rates and identifying factors linked to worse outcomes.

## Contribution

The study provides a detailed clinicopathologic analysis of a rare pancreatic cancer subtype, USCP, and identifies prognostic factors from a single-institution cohort.

## Key findings

- USCP lacks specific symptoms and imaging features, making diagnosis difficult without pathological biopsy.
- Distant metastasis and mesenteric–portal axis invasion are independently associated with poor survival.
- Only one patient survived more than five years, with a median survival of 9.0 months.

## Abstract

The clinical course and surgical outcomes of undifferentiated sarcomatoid carcinoma of the pancreas (USCP) remain poorly characterized owing to its rarity. This study aimed to describe the histology, clinicopathologic features, perioperative outcomes, and overall survival (OS) of 23 resected USCP patients.

We retrospectively described the histology, clinicopathologic features, perioperative outcomes and OS of patients who underwent pancreatectomy with a final diagnosis of USCP in a single institution.

A total of 23 patients were included in this study. Twelve patients were male, the median age at diagnosis was 61.5 ± 13.0 years (range: 35–89). Patients with USCP had no specific symptoms and characteristic imaging findings. The R0 resection was achieved in 21 cases. The En bloc resection and reconstruction of mesenteric–portal axis was undertaken in 9 patients. There were no deaths attributed to perioperative complications in this study. The intraoperative tumor-draining lymph nodes (TDLNs) dissection was undergone in 14 patients. The 1-, 3- and 5-year survival rates were 43.5%, 4.8% and 4.8% in the whole study, the median survival was 9.0 months. Only 1 patient had survived more than 5 years and was still alive at last follow-up. The presence of distant metastasis (p = 0.004) and the presence of pathologically confirmed mesenteric–portal axis invasion (p = 0.007) was independently associated with poor OS.

USCP was a rare subgroup of pancreatic malignancies with a bleak prognosis. To make a diagnose of USCP by imaging was quite difficult because of the absence of specific manifestations. Accurate diagnosis depended on pathological biopsy, and the IHC profile of USCP was mainly characterized by co-expression of epithelial and mesenchymal markers. A large proportion of patients have an early demise, especially for patients with distant metastasis and pathologically confirmed mesenteric–portal axis invasion. Long-term survival after radical resection of USCPs remains rare.