Common Hepatic Artery Abutment or Encasement Is an Adverse Prognostic Factor in Patients with Borderline and Unresectable Pancreatic Cancer

BACKGROUND

Localized and unresectable pancreatic ductal adenocarcinoma (PDA) comprises one third of new diagnoses and includes borderline resectable (BR) and locally advanced (LA) unresectable disease. In a cohort of patients who were treated and followed at a single institution, we assessed clinical and radiographic predictors of outcome.

METHODS

The study included 69 consecutive patients with BR or LA PDA. Serial imaging studies were reviewed by both a pancreatic surgeon and a radiologist for vascular abutment or encasement by cancer, and they were recorded.

RESULTS

The cohort included 25 patients with BR and 44 patients with LA PDA, with median overall survivals (OS) of 15 and 14 months, respectively (p = 0.802). Fifteen patients were resected (22%), with a median OS of 21 months from diagnosis (HR 2.50, p = 0.006) and 13 months from resection. Median OS from diagnosis was 33 months in patients without lymph node metastases at resection (n = 10), but just 17 months with lymph node metastases (n = 5, HR = 8.95, p = 0.011). There were 12 two-year survivors in the total cohort (17%), and seven of them never underwent resection. First-line treatments consisted of gemcitabine (n = 13), modern first-line combinations (FOLFIRNOX or gemcitabine/nab-paclitaxel, n = 24), or alternative multi-agent therapies (n = 32); there were no statistical differences between treatment subgroups (OS of 10, 13, and 16 months, respectively). Common hepatic artery (CHA) abutment or encasement at diagnosis was associated with poor survival (adjusted hazard ratio, CHA abutment = 2.47 (p = 0.015) and CHA encasement = 2.16 (p = 0.036)).

CONCLUSION

In this cohort, common hepatic arterial abutment or encasement and residual lymph node disease at resection portended a particularly poor outcome in patients with localized, unresectable PDA.

Establishing a Murine Pancreatic Cancer CaSm Model: Up-regulation of CaSm Is Required for the Transformed Phenotype of Murine Pancreatic Adenocarcinoma

We have recently shown that the cancer-associated Sm-like protein (CaSm) is overexpressed in human pancreatic adenocarcinoma (PC). However, the role of CaSm in the process of neoplastic transformation remains unclear. To define further the role of CaSm in PC transformation, we have established a murine model based on the murine pancreatic cancer cell lines Panc02 and Panc03. CaSm is overexpressed in the aggressive Panc02 cells and expressed at much lower levels in the more indolent Panc03 cells. Up-regulation of CaSm in Panc03 cells increased in vitro proliferation and anchorage-independent growth and promoted subcutaneous tumor establishment and growth in syngeneic mice. Conversely, adenoviral down-regulation of CaSm in Panc02 led to significant inhibition of cellular proliferation and anchorage-independent growth in vitro and complete abolition of tumor growth and metastasis in vivo. Up-regulation of CaSm in NIH3T3 resulted in loss of contact inhibition and increased soft agar colony formation in vitro. The requirement for CaSm overexpression for neoplastic transformation confirms the concept that CaSm is a critical oncogene and potential target for molecular intervention. Furthermore, establishment of the murine clinically relevant model of pancreatic metastases provides a framework for the generation of preclinical data to support the development of novel molecular therapies targeting CaSm.