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.

Total neoadjuvant therapy is associated with improved overall survival and pathologic response in pancreatic adenocarcinoma.

BACKGROUND: Few studies have evaluated outcomes of total neoadjuvant therapy (TNT) compared with single modality neoadjuvant therapy (SMNT) or surgery first (SF) for pancreatic ductal adenocarcinoma (PDAC). METHODS: A single-institution retrospective review of PDAC patients who underwent pancreatectomy was conducted (1993-2019). Overall survival (OS) estimates from diagnosis and from surgery were determined using Kaplan-Meier methods; Cox proportional hazards models adjusted for covariates. RESULTS: Surgery was performed upfront (SF) in 168 (46.9%), while 111 (31.0%) had chemotherapy or chemoradiation before resection (SMNT), and 79 (22.1%) underwent TNT (chemotherapy and chemoradiation). Resection margins were more frequently R0 in the TNT group (86.1%) compared with SMNT (64.0%) and SF (72%) (p < 0.001). Complete pathologic response was more common in the TNT group (10.1%) compared with SMNT (3.6%) or SF (0.6%) (p = 0.001), resulting in prolonged survival (median OS = 100.2 months). TNT patients demonstrated longer median OS from surgery (33.6 months) compared with SF (19.1 months) and SMNT (17.4 months) (p = 0.010), which persisted after controlling for covariates. CONCLUSIONS: TNT is associated with more frequent complete pathologic response, a higher rate of margin negative resection, and prolonged OS as compared with SF or SMNT. Additional studies to identify subgroups that derive the greatest benefit are warranted.

Predicting positive peritoneal cytology in pancreatic cancer.

INTRODUCTION: Positive cytology from peritoneal washings obtained prior to potential resection of pancreatic cancer is associated with grim prognosis, equivalent to M1 disease. We examine our experience with pancreatic cancer patients who underwent pre-resection lavage in an attempt to predict who would have malignant cells on peritoneal cytology. METHODS: We conducted a retrospective review of patients undergoing pancreatectomy for pancreatic adenocarcinoma at a tertiary care institution from 1995 to 2019 and had pre-resection lavage performed. Demographic and clinicopathologic data were collected. Logistic regression models were used to identify predictors of positive cytology. RESULTS: Three hundred ninety-nine patients underwent pancreatic resection and had lavage performed. Forty-three (10.8%) had positive peritoneal cytology. Those with positive cytology had higher median Ca19-9 value than those with negative cytology at diagnosis (368.5 vs 200 U/mL, p = 0.007) and after neoadjuvant therapy (100.3 vs 43 U/mL, p = 0.013). After controlling for preoperative therapy received, an initial Ca19-9 greater than 1220 U/mL (OR 2.72, 95% CI 1.07-6.89, p = 0.035), locally advanced disease (OR 4.86, 95% CI 1.31-18.09, p = 0.018), and BMI ≥ 25 kg/m2 (OR 2.67, 95% CI 1.04-6.97, p = 0.042) were associated with positive cytology in multivariate logistic regression model. The associated ROC curve had an AUC of 0.7507, suggesting adequate discrimination of those with positive peritoneal cytology. CONCLUSION: Diagnostic laparoscopy remains an important adjunct to the workup, diagnosis, and staging of pancreatic adenocarcinoma. Patients with locally advanced disease, significantly elevated serum Ca19-9 at diagnosis, and BMI ≥ 25 kg/m2 may be at higher risk for positive peritoneal cytology, regardless of whether neoadjuvant therapy is administered.

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.