MRI-Based Tumor Necrosis Depiction in Pancreatic Ductal Adenocarcinoma: Can It Predict Tumor Aggressiveness?

SIMPLE SUMMARY: Pancreatic adenocarcinoma is a leading cause of cancer related deaths worldwide. Since surgical treatment involves serious risk and morbidity, guiding patients appropriately to surgery for only those that stand to benefit is crucial to avoid unnecessary morbidity. Imaging may provide value in predicting patient prognosis and guiding therapeutic options. Tumor necrosis has been associated with higher tumor grade and worse cancer-specific survival in multiple types of cancers. The purpose of this study was to investigate whether tumor necrosis depicted on abdominal MRI can predict tumor aggressiveness in pancreatic ductal adenocarcinoma. We found that MRI tumor necrosis was associated with higher rates of lymphadenopathy, metastatic disease, and advanced tumor stage compared to pancreatic cancer patients without MRI detectable necrosis. MRI may therefore be prognostically valuable and help guide therapy for patients with pancreatic cancer. ABSTRACT: The purpose of this study was to investigate whether tumor necrosis depicted on contrast-enhanced abdominal MRI can predict tumor aggressiveness in pancreatic ductal adenocarcinoma (PDAC). In this retrospective analysis, we included 71 patients with pathology-proven PDAC who underwent contrast-enhanced MRI from 2006 to 2020. Assessment for the presence/absence of imaging detected necrosis was performed on T2-weighted and contrast-enhanced T1-weighted images. Primary tumor characteristics, regional lymphadenopathy, metastases, stage, and overall survival were analyzed. Fisher’s exact and Mann-Whitney U tests were used for statistical analysis. Of the 72 primary tumors, necrosis was identified on MRI in 58.3% (42/72). Necrotic PDACs were larger (44.6 vs. 34.5 mm, p = 0.0016), had higher rates of regional lymphadenopathy (69.0% vs. 26.7%, p = 0.0007), and more frequent metastases (78.6% vs. 40.0%, p = 0.0010) than those without MRI-evident necrosis. A non-statistically significant reduction in median overall survival was observed in patients with versus without MRI-evident necrosis (15.8 vs. 38.0 months, p = 0.23). PDAC tumor necrosis depicted on MRI was associated with larger tumors and higher frequency of regional lymphadenopathy and metastases.