Total Neoadjuvant Treatment for Pancreatic Ductal Adenocarcinoma Is Associated With Limited Lymph Node Yield but Improved Ratio.

INTRODUCTION: The lymph node yield (LNY) and lymph node ratio (LNR) of nodal metastases following pancreatoduodenectomy (PD) have been reported as prognostic parameters in patients with pancreatic ductal adenocarcinoma (PDAC). However, they have not been compared in the setting of various neoadjuvant therapy modalities. METHODS: A single institutional retrospective study identified 134 patients diagnosed with resectable, BLR- and LA-PDAC who underwent PD at Fox Chase Cancer Center between 2010 and 2019. Patients were categorized based on first-line treatment as follows: surgery first (SF), total neoadjuvant therapy (TNT), and single modality neoadjuvant therapy (SMNT). The histopathological reports of the surgical specimens were examined to obtain LNY and determine the counts of lymph nodes with metastases. Subsequently, LNR was calculated as the number of positive lymph nodes divided by the number of lymph nodes examined. RESULTS: Overall, 49, 38, 27, 12, and 8 patients underwent SF approach, SMNT, incomplete TNT, induction TNT, and consolidation TNT, respectively. There was no difference in R0 resection and vascular resection between the groups (P = 0.096 and 0.794, respectively). The median counts of LNY were 22, 15, 21, 11.5, and 10, respectively (P < 0.001). The average LNR was 0.16, 0.07, 0.03, 0.02, and 0.02, respectively (P < 0.001). There were statistically significant differences in overall survival in the TNT groups (log-rank test P = 0.030). CONCLUSIONS: PDAC patients who undergo the TNT modality exhibit lower LNY and improved LNR compared with the SF approach and SMNT neoadjuvant therapy groups. This is likely explained by the increased treatment response and lymph node obliteration associated with the TNT approach. Our results question the minimal requirement of 11-18 harvested lymph nodes for PD following TNT.

Clinical and Histological Basis of Adenosquamous Carcinoma of the Pancreas: A 30-year Experience.

BACKGROUND: Adenosquamous carcinoma (ASC) of the pancreas is a rare form of malignancy with a poor prognosis. We herein report our case series with review of the contemporary literature. METHODS: With institutional review board approval, we identified 23 patients with pancreatic ASC. RESULTS: ASC was more common in women (61%), with a median age of 73 y at presentation. The tumor was in the head of the pancreas in 65% of cases. Six cases (26%) had resectable disease, three (13%) were borderline resectable, and eight (34.7%) were locally advanced or metastatic. First-line treatment included pancreatic resection in eight cases (34.8%), concurrent neoadjuvant chemoradiation in three (13%), and neoadjuvant chemotherapy in two (8.7%). Most resected tumors had pathological T3 stage (80%). Pathological nodal disease was demonstrated in 60%, and margins were positive in three cases. Complete pathological response was not observed, although fibrosis presented in only one case (10%). Eventually, twenty patients developed metastatic disease. Overall survival is 11.5 [95% confidence interval 6, 14.5] months. CONCLUSIONS: ASC demonstrates a more aggressive malignant phenotype and carries a worse prognosis. Oncological resection is the mainstay of treatment. Neoadjuvant chemoradiation is an emerging approach in the management of ASC that has been extrapolated from the adenocarcinoma neoadjuvant trials.