Prognostic significance of intraoperative peritoneal washing cytology for patients with potentially resectable pancreatic ductal adenocarcinoma

Clinical impact of high-quality testing for peritoneal lavage cytology in pancreatic cancer

In pancreatic ductal adenocarcinoma (PDAC) patients, the importance of peritoneal lavage cytology, which indicates unresectability, remains controversial. This study sought to determine whether positive peritoneal lavage cytology (CY+) precludes pancreatectomy. Furthermore, we propose a novel liquid biopsy using peritoneal lavage fluid to detect viable peritoneal tumor cells (v-PTCs) with TelomeScan F35, a telomerase-specific replication-selective adenovirus engineered to express green fluorescent protein. Resectable cytologically or histologically proven PDAC patients (n = 53) were enrolled. CY was conducted immediately following laparotomy. The resulting fluid was examined by conventional cytology (conv-CY; Papanicolaou staining and MOC-31 immunostaining) and by the novel technique (Telo-CY; using TelomeScan F35). Of them, 5 and 12 were conv-CY+ and Telo-CY+, respectively. All underwent pancreatectomy. The two double-CY+ (conv-CY+ and Telo-CY+) patients showed early peritoneal recurrence (P-rec) postoperatively, despite adjuvant chemotherapy. None of the three conv-CY+ Telo-CY- patients exhibited P-rec. Six of the 10 Telo-CY+ conv-CY- patients (60%) relapsed with P-rec. Of the remaining 38 double-CY- [conv-CY-, Telo-CY-, conv-CY± (Class III)] patients, 3 (8.3%) exhibited P-rec. Although conv-CY+ status predicted poor prognosis and a higher risk of P-rec, Telo-CY was more sensitive for detecting v-PTC. Staging laparoscopy and performing conv-CY and Telo-CY are needed to confirm the indication for pancreatectomy.

Preoperative predictive factors for positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas: a retrospective study

BACKGROUND

The clinical importance of positive peritoneal cytology results in patients with pancreatic ductal adenocarcinomas remains controversial. We evaluated the prognosis of these patients and the predictive preoperative risk factors for positive peritoneal cytology results.

METHODS

We retrospectively reviewed patients who underwent curative-intent surgery at our institution between May 2010 and June 2020. Preoperative risk factors for positive peritoneal cytology results were identified using logistic regression analysis. A scoring model was constructed using the total number of significant independent predictors for positive peritoneal cytology results.

RESULTS

Of 233 patients, 18 (7.7%) had positive peritoneal cytology results. The recurrence-free survival and cancer-specific survival were markedly worse in patients with positive peritoneal cytology results than in those with negative peritoneal cytology results (recurrence-free survival: 6.0 months vs. 16.6 months, p = 0.050; cancer-specific survival: 19.4 months vs. 47.5 months, p = 0.034). Tumor location (odds ratio: 3.760, 95% confidence interval: 1.099-11.818, p = 0.023), tumor size > 25 mm (odds ratio: 3.410, 95% confidence interval: 1.031-11.277, p = 0.046), preoperative serosal invasion (odds ratio: 5.193, 95% confidence interval: 1.099-24.531, p = 0.038), and preoperative carcinoembryonic antigen level > 5.6 ng/mL (odds ratio: 3.816, 95% confidence interval: 1.248-10.667, p = 0.019) were identified as significant independent predictive factors. Our predictive model's optimal cutoff and positive predictive values for positive peritoneal cytology results were 3 and 27.9%, respectively.

CONCLUSIONS

The indications for curative-intent surgery should be considered carefully in patients with high-risk factors for positive peritoneal cytology results.

Evaluating staging laparoscopy indications for pancreatic cancer based on resectability classification and treatment strategies for patients with positive peritoneal washing cytology

Introduction

The prognosis of pancreatic ductal adenocarcinoma (PDAC) in patients with positive peritoneal washing cytology (CY1) is poor. We aimed to evaluate the results of staging laparoscopy (SL) and treatment efficacy in CY1 patients based on a resectability classification.

Methods

We retrospectively reviewed 250 patients with PDAC who underwent SL before the initial treatment between 2017 and 2023 at the University of Toyama.

Results

The breakdown of cases by resectability classification was resectable (R):borderline resectable (BR):unresectable locally advanced (UR-LA) = 131:48:71 cases. The frequency of CY1 increased in proportion to the degree of local progression (R:BR:UR-LA = 20:23:34%), but the frequencies of liver metastasis or peritoneal dissemination were comparable (R:BR:UR-LA = 6.9:6.3:8.5%). Most CY1 patients received gemcitabine along with nab-paclitaxel therapy. The CY-negative conversion rates (R:BR:UR-LA = 70:64:52%) and conversion surgery rates (R:BR:UR-LA = 40:27:9%) were inversely proportional to the degree of local progression.Comparing H0P0CY1 factors for each classification, patients with H0P0CY1 had significantly more pancreatic body or tail carcinoma and tumor size ≥32 mm in R patients, whereas in BR patients, duke pancreatic monoclonal antigen type 2 (DUPAN-2) ≥ 230 U/mL was a significant factor. In contrast, no significant factors were observed in UR-LA patients.

Conclusion

The CY1 rates, CY-negative conversion rates, and conversion surgery rates varied according to local progression. In the case of R and BR, SL could be considered in patients with pancreatic body or tail carcinoma, large tumor size, or high DUPAN-2 level. In UR-LA, SL might be considered for all patients.

Should Positive Cytology Revealed by Intraoperative Lavage Preclude Radical Resection in Resectable Pancreatic Cancer?: A Systemic Review and Meta-analysis

OBJECTIVES

The aims of this review were to determine whether positive peritoneal lavage cytology (CY+) precludes radical resection in pancreatic cancer and to propose prospections for future studies.

METHODS

MEDLINE, Embase, and Cochrane Central were searched for related articles. Dichotomous variables and survival outcomes were analyzed with the estimation of odds ratio and hazards ratio (HR), respectively.

RESULTS

A total of 4905 patients were included, of which 7.8% were CY+. Positive peritoneal lavage cytology was correlated with poor overall survival (univariate survival analysis [HR, 2.35; P < 0.00001]; multivariate analysis [HR, 1.62; P < 0.00001]), poor recurrence-free survival (univariate survival analysis [HR, 2.50; P < 0.00001]; multivariate analysis [HR, 1.84; P < 0.00001]), and higher initial peritoneal recurrence rate (odds ratio, 5.49; P < 0.00001).

CONCLUSIONS

Although CY+ predicts poor prognosis and a higher risk of peritoneal metastasis after curative resection, it is not sufficient to preclude curative resection based on the current evidence, and high-quality trials should be conducted to assess the prognostic impact of operation among resectable CY+ patients. In addition, more sensitive and accurate methods to detect peritoneal exfoliated tumor cells and more effective comprehensive treatment for resectable CY+ pancreatic cancer patients are clearly warranted.

Prognostic Significance of Intraoperative Peritoneal Lavage Cytology in Patients with Pancreatic Ductal Adenocarcinoma: A Single-Center Experience and Systematic Review of the Literature

BACKGROUND

The prognostic significance of peritoneal lavage cytology (PLC) in patients with pancreatic ductal adenocarcinoma (PDAC) remains controversial. The purpose of this study was to evaluate the prognostic impact of PLC status in PDAC patients.

METHODS

Patients intending to undergo resection for PDAC between 2007 and 2020 were included. Survival was compared among patients who underwent resection with negative or positive PLC status and those who did not undergo resection. Univariable and multivariable analyses were conducted to evaluate the prognostic impact of positive PLC status. A systematic literature review was performed to evaluate the correlation between prognosis and the positive PLC rate.

RESULTS

A total of 480 patients formed the study cohort and were divided as follows: 438 in the negative PLC group, 18 in the positive PLC group, and 24 in the no resection group. Although the median survival time significantly differed between the negative and positive PLC groups (35.7 vs. 13.6 months, P < 0.001), it did not significantly differ between the positive PLC and no resection groups (13.6 vs. 12.2 months, P = 0.605). Multivariable analyses demonstrated that positive PLC status (hazard ratio = 3.54, 95% confidence interval = 1.97-6.38, P < 0.001) was the strongest poor prognostic factor. Based on statistical analyses for the systematic review, the prognostic impact of positive PLC status weakened significantly as the institutional positive PLC rate increased (P = 0.044).

CONCLUSIONS

Resection did not improve the prognosis of patients with positive PLC status in our cohort. The institutional positive PLC rate may be a good reference for surgical indication in these patients.

Humanized anti-DEspR IgG4S228P antibody increases overall survival in a pancreatic cancer stem cell-xenograft peritoneal carcinomatosis ratnu/nu model

BACKGROUND

Pancreatic peritoneal carcinomatosis (PPC), with the worst median overall-survival (mOS), epitomizes the incurability of metastatic cancer. Cancer stem cells (CSCs) underpin this incurability. However, inhibitors of CSC-stemness fail to increase mOS in cancer patients despite preclinical tumor-reduction. This shortfall reinforces that preclinical efficacy should be defined by increased mOS in the presence of cancer comorbidities, CSC-heterogeneity and plasticity. The primary objectives of this study are: to test the dual endothelin-1/signal peptide receptor, DEspR, as a nodal therapeutic target in PPC, given DEspR induction in anoikis-resistant pancreatic CSCs, and to validate humanized anti-DEspR antibody, hu-6g8, as a potential therapeutic for PPC.

METHODS

We used heterogeneous pools of CSCs selected for anoikis resistance from reprogrammed Panc1 and MiaPaCa2 tumor cells (TCs), and adherent TCs reprogrammed from CSCs (cscTCs). We used multiple anti-DEspR blocking antibodies (mAbs) with different epitopes, and a humanized anti-DEspR recombinant mAb cross-reactive in rodents and humans, to test DEspR inhibition effects. We measured DEspR-inhibition efficacy on multiple prometastatic CSC-functions in vitro, and on tumorigenesis and overall survival in a CSC-derived xenograft (CDX) nude rat model of PPC with comorbidities.

RESULTS

Here we show that DEspR, a stress-survival receptor, is present on subsets of PDAC Panc1-TCs, TC-derived CSCs, and CSC-differentiated TCs (cscTCs), and that DESpR-inhibition decreases apoptosis-resistance and pro-metastatic mesenchymal functions of CSCs and cscTCs in vitro. We resolve the DNA-sequence/protein-function discordance by confirming ADAR1-RNA editing-dependent DEspR-protein expression in Panc1 and MiaPaCa2 TCs. To advance DEspR-inhibition as a nodal therapeutic approach for PPC, we developed and show improved functionality of a recombinant, humanized anti-DEspR IgG4S228P antibody, hu-6g8, over murine precursor anti-DEspR mabs. Hu-6g8 internalizes and translocates to the nucleus colocalized with cyto-nuclear shuttling galectins-1/3, and induces apoptotic cell changes. DEspR-inhibition blocks transperitoneal dissemination and progression to peritoneal carcinomatosis of heterogeneous DEspR±/CD133 ± Panc1-derived CSCs in xenografted nude rats, improving mOS without chemotherapy-like adverse effects. Lastly, we show DEspR expression in Stage II-IV primary and invasive TCs in the stroma in PDAC-patient tumor arrays.

CONCLUSION

Collectively, the data support humanized anti-DEspR hu-6g8 as a potential targeted antibody-therapeutic with promising efficacy, safety and prevalence profiles for PPC patients.

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.

Primary tumor types and origins in positive abdominopelvic washing cytology, a single institution experience

INTRODUCTION

Abdominopelvic washing cytology is a common specimen evaluated for ovarian, fallopian tubal, and peritoneal cancer staging or other nongynecologic malignancies presented as metastases. We reviewed our experience in diagnosing abdominopelvic washing specimens and assessing the primary tumor types and origins of the positive abdominopelvic washings.

MATERIALS AND METHODS

A pathology archive database search was performed for abdominopelvic washing specimens from 2007 to 2018. The corresponding cytologic diagnoses, results of ancillary studies, clinical histories, and surgical follow-up were reviewed. The primary sites were determined based on the synoptic reports, when available.

RESULTS

A total of 5.8% (350 of 6023) of cases were positive for malignancy or neoplasm. Additionally, 1.3% (78 of 6023) were diagnosed as atypical cells. Of the 350 positive cases, 93.4% were müllerian tumors. The frequency of primary sites for müllerian tumors in descending order were: ovary, uterus, fallopian tube, peritoneum, and uncertain müllerian sites. The common ovarian tumors identified in pelvic washing in descending order were: high-grade serous carcinoma, serous borderline tumor, clear cell carcinoma, low-grade serous carcinoma, and endometrioid carcinoma. Gastrointestinal, breast, bladder, and lymphoma primaries were the 23 nongynecologic tumors identified in pelvic washings.

CONCLUSIONS

Positive findings in abdominopelvic washing cytology is rare. The majority of the positive cases were from müllerian origins, with ovary and uterus as the most common sites. Endometrial adenocarcinoma, endometrioid type and ovarian high-grade serous carcinoma were the most common tumor types. Knowing prior history of malignancy, morphologic comparison with concurrent surgical cases, and performing ancillary studies are keys to improve diagnostic accuracy of abdominopelvic washings.

MiR-194-5p in Pancreatic Ductal Adenocarcinoma Peritoneal Washings is Associated with Peritoneal Recurrence and Overall Survival in Peritoneal Cytology-Negative Patients

BACKGROUND

Peritoneal dissemination is one of the major recurrence patterns in patients with pancreatic ductal adenocarcinoma (PDAC) and is associated with poor prognosis. Here, we assessed the diagnostic potential of microRNA (miRNA) profiles in peritoneal washings for prediction of peritoneal dissemination in PDAC.

PATIENTS AND METHODS

From January 2016 to July 2017, peritoneal washings were obtained prospectively from 59 patients with PDAC undergoing surgery the Yokohama City University Hospital. MiRNA expression was evaluated by Agilent human miRNA microarray and quantitative reverse-transcription polymerase chain reaction.

RESULTS

Microarray analysis identified upregulated and downregulated miRNAs in peritoneal washings of patients with peritoneal dissemination. We validated four miRNAs (miR-141-3p, miR-194-3p, miR-194-5p, and miR-200c-3p) with high expression in peritoneal washings. The cumulative incidence rate of peritoneal recurrence in peritoneal cytology-negative patients in the miR-194-5p high group was significantly higher than that in the miR-194-5p low group (p = 0.002). Univariate and multivariate analyses revealed that high miR-194-5p was associated with overall survival (OS).

CONCLUSIONS

High expression of miR-194-5p in peritoneal washings is associated with peritoneal recurrence and poor OS in patients with peritoneal cytology-negative PDAC.

Meta-analysis of recurrence pattern after resection for pancreatic cancer

Background

Initial recurrence mapping of resected pancreatic ductal adenocarcinoma (PDAC) could help in stratifying patient subpopulations for optimal postoperative follow-up. The aim of this systematic review and meta-analysis was to investigate the initial recurrence patterns of PDAC and to correlate them with clinicopathological factors.

Methods

MEDLINE and Web of Science databases were searched systematically for studies reporting first recurrence patterns after PDAC resection. Data were extracted from the studies selected for inclusion. Pooled odds ratios (ORs) and 95 per cent confidence intervals were calculated to determine the clinicopathological factors related to the recurrence sites. The weighted average of median overall survival was calculated.

Results

Eighty-nine studies with 17 313 patients undergoing PDAC resection were included. The weighted median rates of initial recurrence were 20·8 per cent for locoregional sites, 26·5 per cent for liver, 11·4 per cent for lung and 13·5 per cent for peritoneal dissemination. The weighted median overall survival times were 19·8 months for locoregional recurrence, 15·0 months for liver recurrence, 30·4 months for lung recurrence and 14·1 months for peritoneal dissemination. Meta-analysis revealed that R1 (direct) resection (OR 2·21, 95 per cent c.i. 1·12 to 4·35), perineural invasion (OR 5·19, 2·79 to 9·64) and positive peritoneal lavage cytology (OR 5·29, 3·03 to 9·25) were significantly associated with peritoneal dissemination as initial recurrence site. Low grade of tumour differentiation was significantly associated with liver recurrence (OR 4·15, 1·71 to 10·07).

Conclusion

Risk factors for recurrence patterns after surgery could be considered for specific surveillance and treatments for patients with pancreatic cancer.

Intraoperative Peritoneal Washing Cytology on Survival in Pancreatic Ductal Adenocarcinoma With Resectable, Locally Advanced, and Metastatic Disease

OBJECTIVES

The prognostic implications of intraoperative peritoneal washing cytology (IPWC) in patients with pancreatic ductal adenocarcinoma (PDAC) remains incompletely understood.

METHODS

A meta-analysis was conducted to investigate the impact of IPWC status on the clinicopathologic features and survival outcomes in potentially resectable, locally advanced, and metastatic PDAC. Hazard ratio (HR) and 95% confidence interval (CI) were used as the pooled estimates.

RESULTS

A total of 12 studies qualified for inclusion with 3751 PDAC patients. In resectable PDAC, the postoperative 5-year overall survival was significantly better in negative IPWC than in positive IPWC patients, with a pooled HR of 2.47 (95% CI, 1.90-3.21; P < 0.001; I = 69%) in a random-effects model. Likely, combined outcome showed a significantly longer survival benefit in the negative IPWC group (HR, 2.80; 95% CI, 1.94-4.04; P < 0.001) in terms of recurrence-free survival. The presence of positive IPWC did not significantly alter survival outcomes in those PDAC patients with locally advanced or metastatic disease.

CONCLUSIONS

This systematic review and meta-analysis demonstrated that a positive IPWC status in patients with clinically resectable PDAC predicts a poor prognosis. Patients with positive IPWC should be regarded as a specific subgroup, with intensive adjuvant chemotherapy that seems to be warranted for further evaluation.

Resistance to anoikis in transcoelomic shedding: the role of glycolytic enzymes

Detachment of cells from the extracellular matrix into the peritoneal cavity initiates a cascade of metabolic alterations, leading usually to cell death by apoptosis, so-called anoikis. Glycolytic enzymes enable the switch from oxidative phosphorylation to aerobic glycolysis and allow resistance to anoikis of shed tumour cells. These enzymes also have moonlighting activities as protein kinases and transcription factors. Phosphoglycerate kinase (PGK) and pyruvate kinase are the only glycolytic enzymes generating ATP in the hexokinase pathway. Hypoxia, EGFR activation, expression of K-Ras G12V and B-Raf V600E induce mitochondrial translocation of phosphoglycerate kinase 1 (PGK1). Mitochondrial PGK1 acts as a protein kinase to phosphorylate pyruvate dehydrogenase kinase 1 (PDHK1), reducing mitochondrial pyruvate utilization, suppressing reactive oxygen species production, increasing lactate production and promoting tumourigenesis. PGK1 also plays a role as a transcription factor once transported into the nucleus. Resistance to anoikis is also facilitated by metabolic support provided by cancer-associated fibroblasts (CAFs). Our series of experiments in-vitro and in the animal model showed that PGK1 knock-out or inhibition is effective in controlling development and growth of peritoneal metastasis (PM) of gastric origin, establishing a causal role of PGK1 in this development. PGK1 also increases CXCR4 and CXCL12 expression, which is associated with a metastatic phenotype and plays a role in the metastatic homing of malignant cells. Thus, PGK1, its modulators and target genes may be exploited as therapeutic targets for preventing development of PM and for enhancing cytotoxic effects of conventional systemic chemotherapy.

Subclinical cancer cell dissemination in peritoneal lavage fluid detected by reverse-transcription polymerase chain reaction identifies patients at high risk for peritoneal recurrence and consequent impaired survival in the setting of preoperative chemoradiation therapy for pancreatic cancer

BACKGROUND

Preoperative chemoradiation therapy is a promising strategy for pancreatic cancer. Peritoneal recurrence is a major recurrence pattern after surgery for pancreatic cancer following preoperative chemoradiation therapy, even in patients with negative peritoneal lavage fluid cytology. Previous reports have indicated that the detection of carcinoembryonic antigen mRNA by reverse transcription polymerase chain reaction is useful for evaluating subclinical tumor cell dissemination in peritoneal lavage fluid.

METHODS

Patients with resectable and borderline resectable pancreatic cancer treated with preoperative gemcitabine-based chemoradiation therapy and subsequent surgery were enrolled in this study. In all patients, a conventional cytologic examination of peritoneal lavage fluid from laparotomy confirmed the negative peritoneal cytology status. Carcinoembryonic antigen mRNA was detected in the peritoneal lavage fluid at laparotomy using reverse transcription polymerase chain reaction. Recurrence patterns and survival were evaluated in association with the carcinoembryonic antigen mRNA status in the peritoneal lavage fluid.

RESULTS

The peritoneal lavage fluid from 57 of the 237 patients (24%) was carcinoembryonic antigen mRNA(+). The carcinoembryonic antigen mRNA(+) patients had a significantly higher incidence of peritoneal recurrence than the carcinoembryonic antigen mRNA(-) patients (36% vs. 15%, P < .001). The 5-year survival rates of the carcinoembryonic antigen mRNA(+) and carcinoembryonic antigen mRNA(-) patients were 31% and 51%, respectively (P = .037). A multivariable analysis for survival revealed that borderline resectability, positive nodal status, and positive carcinoembryonic antigen mRNA status were independent variables for impaired survival.

CONCLUSION

Carcinoembryonic antigen mRNA(+) status was associated with a significantly increased incidence of peritoneal recurrence in patients with pancreatic cancer treated with preoperative chemoradiation therapy, resulting in impaired survival.

Reappraisal of Staging Laparoscopy for Patients with Pancreatic Adenocarcinoma: A Contemporary Analysis of 1001 Patients

BACKGROUND

Recent advances in imaging and the increasing use of neoadjuvant therapy puts the contemporary utility of staging laparoscopy for patients with pancreatic adenocarcinoma (PDAC) into question. This study aimed to develop a prognostic score to optimize prevention of an unnecessary laparotomy and minimize the rate for unnecessary laparoscopy.

METHODS

Clinicopathologic data were evaluated for all patients undergoing surgical intervention for PDAC between 2001 and 2015, who were stratified into group 1 (2001-2008) and group 2 (2009-2014).

RESULTS

The study identified 1001 patients eligible for analysis, 331 (33%) of whom underwent a staging laparoscopy before exploration. An unnecessary laparotomy was prevented for 44.4% of the patients in period 1 and for 24% of the patients in period 2 (p < 0.001). Male gender [odds ratio (OR), 1.8; p < 0.05], preoperative resectability (borderline resectable OR 2.1; p < 0.019; locally advanced OR 7.6; p < 0.001), CA 19-9 levels higher than 394 U/L (OR 3.1; p < 0.001), no neoadjuvant chemotherapy (OR 2.7; p = 0.012), and pancreatic body or tail lesions (OR 1.8; p = 0.063) were predictive of occult metastatic disease. The developed scoring index demonstrated a c-statistic of 0.729. The observed-to-expected ratio for the index at every score level validated the index's model. A score cutoff at 4 was able to detect 76.1% of radiographically occult metastatic disease.

CONCLUSION

The rate for unnecessary laparotomy among patients with PDAC has decreased in contemporary times, but unnecessary laparotomy still occurs for 1 in 4 patients. Using our scoring system, a cutoff of 4 allows 76% of radiographically occult metastases to be predicted, thereby selecting high-risk patients for laparoscopic biopsy and potentially avoiding a non-therapeutic laparotomy.

Regional immunotherapy for liver and peritoneal metastases

Pancreatic adenocarcinoma is a biologically aggressive disease, with liver and peritoneal metastases being a frequent cause of death. We examine how the pancreatic carcinoma microenvironment and immunosuppressive landscape favor tumor progression. Immunotherapy has shown promise in select solid tumors, yet challenges remain in applying these gains to stage IV pancreatic adenocarcinoma. We discuss how regional therapy strategies may be leveraged to open new avenues for treating pancreatic carcinoma metastases with immunotherapy.