The Difficulty of Detecting Occult Metastases in Patients with Potentially Resectable Pancreatic Cancer: Development and External Validation of a Preoperative Prediction Model.

Occult metastases are detected in 10-15% of patients during exploratory laparotomy for pancreatic cancer. This study developed and externally validated a model to predict occult metastases in patients with potentially resectable pancreatic cancer. Model development was performed within the Dutch Pancreatic Cancer Audit, including all patients operated for pancreatic cancer (January 2013-December 2017). Multivariable logistic regression analysis based on the Akaike Information Criteria was performed with intraoperative pathologically proven metastases as the outcome. The model was externally validated with a cohort from the University Hospital of Verona (January 2013-December 2017). For model development, 2262 patients were included of whom 235 (10%) had occult metastases, located in the liver (n = 143, 61%), peritoneum (n = 73, 31%), or both (n = 19, 8%). The model included age (OR 1.02, 95% CI 1.00-1.03), BMI (OR 0.96, 95% CI 0.93-0.99), preoperative nutritional support (OR 1.73, 95% CI 1.01-2.74), tumor diameter (OR 1.60, 95% CI 1.04-2.45), tumor composition (solid vs. cystic) (OR 2.33, 95% CI 1.20-4.35), and indeterminate lesions on preoperative imaging (OR 4.01, 95% CI 2.16-7.43). External validation showed poor discrimination with a C-statistic of 0.56. Although some predictor variables were significantly associated with occult metastases, the model performed insufficiently at external validation.

Dynamics of Serum CA19-9 in Patients Undergoing Pancreatic Cancer Resection.

BACKGROUND: Carbohydrate antigen (CA) 19-9 is an established perioperative prognostic biomarker for pancreatic ductal adenocarcinoma (PDAC). However, it is unclear how CA19-9 monitoring should be used during postoperative surveillance to detect recurrence and to guide the initiation of recurrence-focused therapy. OBJECTIVE: This study aimed to elucidate the value of CA19-9 as a diagnostic biomarker for disease recurrence in patients who underwent PDAC resection. METHODS: Serum CA19-9 levels at diagnosis, after surgery, and during postoperative follow-up were analyzed in patients who underwent PDAC resection. All patients with at least two postoperative follow-up CA19-9 measurements before recurrence were included. Patients deemed to be nonsecretors of CA19-9 were excluded. The relative increase in postoperative CA19-9 was calculated for each patient by dividing the maximum postoperative CA19-9 value by the first postoperative value. Receiver operating characteristic analysis was performed to identify the optimal threshold for the relative increase in CA19-9 levels to identify recurrence in the training set using Youden's index. The performance of this cutoff was validated in a test set by calculating the area under the curve (AUC) and was compared to the performance of the optimal cutoff for postoperative CA19-9 measurements as a continuous value. In addition, sensitivity, specificity, and predictive values were assessed. RESULTS: In total, 271 patients were included, of whom 208 (77%) developed recurrence. Receiver operating characteristic analysis demonstrated that a relative increase in postoperative serum CA19-9 of 2.6× was predictive of recurrence, with 58% sensitivity, 83% specificity, 95% positive predictive value, and 28% negative predictive value. The AUC for a 2.6× relative increase in the CA19-9 level was 0.719 in the training set and 0.663 in the test set. The AUC of postoperative CA19-9 as a continuous value (optimal threshold, 52) was 0.671 in the training set. In the training set, the detection of a 2.6-fold increase in CA19-9 preceded the detection of recurrence by a mean difference of 7 months ( P <0.001) and in the test set by 10 months ( P <0.001). CONCLUSIONS: A relative increase in the postoperative serum CA19-9 level of 2.6-fold is a stronger predictive marker for recurrence than a continuous CA19-9 cutoff. A relative CA19-9 increase can precede the detection of recurrence on imaging for up to 7 to 10 months. Therefore, CA19-9 dynamics can be used as a biomarker to guide the initiation of recurrence-focused treatment.

Recent Advances and Future Challenges in Pancreatic Cancer Care: Early Detection, Liquid Biopsies, Precision Medicine and Artificial Intelligence.

The incidence of pancreatic ductal adenocarcinoma (PDAC) is rising. While surgical techniques and peri-operative care have improved, the overall survival for PDAC remains poor. Thus, novel and bold research initiatives are needed along the spectrum of clinical care, a few of which will be discussed in this article. Early detection is crucial, with specific high-risk groups possibly benefiting from targeted screening programs. Liquid biopsies (such as circulating exosomes, tumor DNA, or tumor cells) offer promise as multifunctional biomarkers for early detection, treatment guidance, and recurrence monitoring. Precision medicine is being explored via targeted therapies for actionable mutations, such as PARP inhibitors for BRCA mutations, and immunotherapy strategies. Artificial intelligence (AI) is emerging as a powerful tool in medical imaging, biomarker discovery, genetics research, and treatment planning, and it can aid in diagnosis, treatment selection, and patient monitoring. However, its associated challenges include ethics, data security, algorithm reliability, and validation. Collaborative efforts between medical professionals, researchers, and AI experts are vital for unlocking AI's potential to enhance pancreatic cancer care. In conclusion, despite the challenges, advancements in liquid biopsies, precision medicine, and AI offer hope for enhancing the diagnosis, treatment, and management of pancreatic cancer.

Predicting post-recurrence survival for patients with pancreatic cancer recurrence after primary resection: A Bi-institutional validated risk classification.

BACKGROUND: Over 80% of patients will develop disease recurrence after radical resection of pancreatic ductal adenocarcinoma (PDAC). This study aims to develop and validate a clinical risk score predicting post-recurrence survival (PRS) at time of recurrence. METHODS: All patients who had recurrence after undergoing pancreatectomy for PDAC at the Johns Hopkins Hospital or at the Regional Academic Cancer Center Utrecht during the study period were included. Cox proportional hazard model was used to develop the risk model. Performance of the final model was assessed in a test set after internal validation. RESULTS: Of 718 resected PDAC patients, 72% had recurrence after a median follow-up of 32 months. The median overall survival was 21 months and the median PRS was 9 months. Prognostic factors associated with shorter PRS were age (hazard ratio [HR] 1.02; 95% confidence interval [95%CI] 1.00-1.04), multiple-site recurrence (HR 1.57; 95%CI 1.08-2.28), and symptoms at time of recurrence (HR 2.33; 95%CI 1.59-3.41). Recurrence-free survival longer than 12 months (HR 0.55; 95%CI 0.36-0.83), FOLFIRINOX and gemcitabine-based adjuvant chemotherapy (HR 0.45; 95%CI 0.25-0.81; HR 0.58; 95%CI 0.26-0.93, respectively) were associated with a longer PRS. The resulting risk score had a good predictive accuracy (C-index: 0.73). CONCLUSION: This study developed a clinical risk score based on an international cohort that predicts PRS in patients who underwent surgical resection for PDAC. This risk score will become available on www.evidencio.com and can help clinicians with patient counseling on prognosis.

[Acute abdominal pain due to internal herniation: a rare phenomenon in a patient without relevant medical history]. / Acute buik door inwendige herniatie.

BACKGROUND: The foramen of Winslow is the opening between the peritoneum and the omental bursa just caudal to the liver and dorsal to the lesser omentum. Internal herniation of the intestine through the foramen of Winslow can cause acute abdominal pain. CASE DESCRIPTION: A 45-year old man without relevant medical history presented with acute abdominal pain. CT scan showed an internal herniation of the intestine through the foramen of Winslow, with signs of ischemia of the herniated intestine. Emergency laparoscopy was performed. The herniated intestine was decompressed with a needle before it could be repositioned, no resection was necessary. Postoperative course was characterized by a paralytic ileus, eventually the patient was discharged on postoperative day 8. CONCLUSION: Internal herniation of the intestine through the foramen of Winslow is a rare cause of acute abdominal pain, which requires surgery to reposition the intestine.

Early Recurrence After Resection of Locally Advanced Pancreatic Cancer Following Induction Therapy: An International Multicenter Study.

OBJECTIVE: To establish an evidence-based cutoff and predictors for early recurrence in patients with resected locally advanced pancreatic cancer (LAPC). BACKGROUND: It is unclear how many and which patients develop early recurrence after LAPC resection. Surgery in these patients is probably of little benefit. METHODS: We analyzed all consecutive patients undergoing resection of LAPC after induction chemotherapy who were included in prospective databases in The Netherlands (2015-2019) and the Johns Hopkins Hospital (2016-2018). The optimal definition for "early recurrence" was determined by the post-recurrence survival (PRS). Patients were compared for overall survival (OS). Predictors for early recurrence were evaluated using logistic regression analysis. RESULTS: Overall, 168 patients were included. After a median follow-up of 28 months, recurrence was observed in 118 patients (70.2%). The optimal cutoff for recurrence-free survival to differentiate between early (n=52) and late recurrence (n=66) was 6 months ( P <0.001). OS was 8.4 months [95% confidence interval (CI): 7.3-9.6] in the early recurrence group (n=52) versus 31.1 months (95% CI: 25.7-36.4) in the late/no recurrence group (n=116) ( P <0.001). A preoperative predictor for early recurrence was postinduction therapy carbohydrate antigen (CA) 19-9≥100 U/mL [odds ratio (OR)=4.15, 95% CI: 1.75-9.84, P =0.001]. Postoperative predictors were poor tumor differentiation (OR=4.67, 95% CI: 1.83-11.90, P =0.001) and no adjuvant chemotherapy (OR=6.04, 95% CI: 2.43-16.55, P <0.001). CONCLUSIONS: Early recurrence was observed in one third of patients after LAPC resection and was associated with poor survival. Patients with post-induction therapy CA 19-9 ≥100 U/mL, poor tumor differentiation and no adjuvant therapy were especially at risk. This information is valuable for patient counseling before and after resection of LAPC.

A Delay in Adjuvant Therapy Is Associated With Worse Prognosis Only in Patients With Transitional Circulating Tumor Cells After Resection of Pancreatic Ductal Adenocarcinoma.

OBJECTIVES: The aim of the study was to assess the association of circulating tumor cells (CTCs) with survival as a biomarker in pancreatic ductal adenocarcinoma (PDAC) within the context of a delay in the initiation of adjuvant therapy. BACKGROUND: Outcomes in patients with PDAC remain poor and are driven by aggressive systemic disease. Although systemic therapies improve survival in resected patients, factors such as a delay in the initiation of adjuvant therapy are associated with worse outcomes. CTCs have previously been shown to be predictive of survival. METHODS: A retrospective study was performed on PDAC patients enrolled in the prospective CircuLating tUmor cellS in pancreaTic cancER trial (NCT02974764) on CTC-dynamics at the Johns Hopkins Hospital. CTCs were isolated based on size (isolation by size of epithelial tumor cells; Rarecells) and counted and characterized by subtype using immunofluorescence. The preoperative and postoperative blood samples were used to identify 2 CTC types: epithelial CTCs (eCTCs), expressing pancytokeratin, and transitional CTCs (trCTCs), expressing both pancytokeratin and vimentin. Patients who received adjuvant therapy were compared with those who did not. A delay in the receipt of adjuvant therapy was defined as the initiation of therapy ≥8 weeks after surgical resection. Clinicopathologic features, CTCs characteristics, and outcomes were analyzed. RESULTS: Of 101 patients included in the study, 43 (42.5%) experienced a delay in initiation and 20 (19.8%) did not receive adjuvant therapy. On multivariable analysis, the presence of trCTCs ( P =0.002) and the absence of adjuvant therapy ( P =0.032) were associated with worse recurrence-free survival (RFS). Postoperative trCTC were associated with poorer RFS, both in patients with a delay in initiation (12.4 vs 17.9 mo, P =0.004) or no administration of adjuvant chemotherapy (3.4 vs NR, P =0.016). However, it was not associated with RFS in patients with timely initiation of adjuvant chemotherapy ( P =0.293). CONCLUSIONS: Postoperative trCTCs positivity is associated with poorer RFS only in patients who either experience a delay in initiation or no receipt of adjuvant therapy. This study suggests that a delay in the initiation of adjuvant therapy could potentially provide residual systemic disease (trCTCs) a window of opportunity to recover from the surgical insult. Future studies are required to validate these findings and explore the underlying mechanisms involved.

Geographic variation in attitudes regarding management of locally advanced pancreatic cancer.

Background: Recent literature suggests wide variations exist in the international management of locally advanced pancreatic cancer. This study sought to evaluate how geography contributes to variations in management of locally advanced pancreatic cancer. Methods: An electronic survey investigating preferences for the evaluation and management of locally advanced pancreatic cancer was distributed to an international cohort of pancreatic surgeons. Surgeons were classified according to geographic location of practice, and survey responses were compared across locations. Results: A total of 153 eligible responses were received from 4 continents: North and South America (n = 94, 61.4%), Europe (n = 25, 16.3%), and Asia (n = 34, 22.2%). Preferences for the use and duration of neoadjuvant chemotherapy and radiotherapy varied widely. For example, participants in Asia commonly preferred 2 months of neoadjuvant chemotherapy (61.8%), whereas North and South American participants preferred 4 months (52.1%), and responses in Europe were mixed (P = .006). Participants in Asia were less likely to consider isolated liver or lung metastases contraindications to exploration and consequently had a greater propensity to consider exploration in a vignette of oligometastatic disease (56.7% vs North and South America: 25.6%, Europe: 43.5%; P = .007). Conclusion: In an international survey of pancreatic surgeons, attitudes regarding locally advanced pancreatic cancer and metastatic disease management varied widely across geographic locations. Better evidence is needed to define optimal management of locally advanced pancreatic cancer.

Nationwide Validation of the 8th American Joint Committee on Cancer TNM Staging System and Five Proposed Modifications for Resected Pancreatic Cancer.

BACKGROUND: The prognostic value of four proposed modifications to the 8th American Joint Committee on Cancer (AJCC) TNM staging system has yet to be evaluated. This study aimed to validate five proposed modifications. METHODS: Patients who underwent pancreatic ductal adenocarcinoma resection (2014-2016), as registered in the prospective Dutch Pancreatic Cancer Audit, were included. Stratification and prognostication of TNM staging systems were assessed using Kaplan-Meier curves, Cox proportional hazard analyses, and C-indices. A new modification was composed based on overall survival (OS). RESULTS: Overall, 750 patients with a median OS of 18 months (interquartile range 10-32) were included. The 8th edition had an increased discriminative ability compared with the 7th edition {C-index 0.59 (95% confidence interval [CI] 0.56-0.61) vs. 0.56 (95% CI 0.54-0.58)}. Although the 8th edition showed a stepwise decrease in OS with increasing stage, no differences could be demonstrated between all substages; stage IIA vs. IB (hazard ratio [HR] 1.30, 95% CI 0.80-2.09; p  = 0.29) and stage IIB vs. IIA (HR 1.17, 95% CI 0.75-1.83; p  = 0.48). The four modifications showed comparable prognostic accuracy (C-index 0.59-0.60); however, OS did not differ between all modified TNM stages (ns). The new modification, migrating T3N1 patients to stage III, showed a C-index of 0.59, but did detect significant survival differences between all TNM stages (p  < 0.05). CONCLUSIONS: The 8th TNM staging system still lacks prognostic value for some categories of patients, which was not clearly improved by four previously proposed modifications. The modification suggested in this study allows for better prognostication in patients with all stages of disease.

Detection, Treatment, and Survival of Pancreatic Cancer Recurrence in the Netherlands: A Nationwide Analysis.

OBJECTIVE: To evaluate whether detection of recurrent pancreatic ductal adenocarcinoma (PDAC) in an early, asymptomatic stage increases the number of patients receiving additional treatment, subsequently improving survival. SUMMARY OF BACKGROUND DATA: International guidelines disagree on the value of standardized postoperative surveillance for early detection and treatment of PDAC recurrence. METHODS: A nationwide, observational cohort study was performed including all patients who underwent PDAC resection (2014-2016). Prospective baseline and perioperative data were retrieved from the Dutch Pancreatic Cancer Audit. Data on follow-up, treatment, and survival were collected retrospectively. Overall survival (OS) was evaluated using multivariable Cox regression analysis, before and after propensity-score matching, stratified for patients with symptomatic and asymptomatic recurrence. RESULTS: Eight hundred thirty-six patients with a median follow-up of 37 months (interquartile range 30-48) were analyzed. Of those, 670 patients (80%) developed PDAC recurrence after a median follow-up of 10 months (interquartile range 5-17). Additional treatment was performed in 159/511 patients (31%) with symptomatic recurrence versus 77/159 (48%) asymptomatic patients (P < 0.001). After propensity-score matching on lymph node ratio, adjuvant therapy, disease-free survival, and recurrence site, additional treatment was independently associated with improved OS for both symptomatic patients [hazard ratio 0.53 (95% confidence interval 0.42-0.67); P < 0.001] and asymptomatic patients [hazard ratio 0.45 (95% confidence interval 0.29-0.70); P < 0.001]. CONCLUSIONS: Additional treatment of PDAC recurrence was independently associated with improved OS, with asymptomatic patients having a higher probability to receive recurrence treatment. Therefore, standardized postoperative surveillance aiming to detect PDAC recurrence before the onset of symptoms has the potential to improve survival. This provides a rationale for prospective studies on standardized surveillance after PDAC resection.

Preoperative predictors for early and very early disease recurrence in patients undergoing resection of pancreatic ductal adenocarcinoma.

BACKGROUND: This study aimed to identify predictors for early and very early disease recurrence in patients undergoing resection of pancreatic ductal adenocarcinoma (PDAC) resection with and without neoadjuvant therapy. METHODS: Included were patients who underwent PDAC resection (2014-2016). Multivariable multinomial regression was performed to identify preoperative predictors for manifestation of recurrence within 3, 6 and 12 months after PDAC resection. RESULTS: 836 patients with a median follow-up of 37 (interquartile range [IQR] 30-48) months and overall survival of 18 (IQR 10-32) months were analyzed. 670 patients (80%) developed recurrence: 82 patients (10%) <3 months, 96 patients (11%) within 3-6 months and 226 patients (27%) within 6-12 months. LogCA 19-9 (OR 1.25 [95% CI 1.10-1.41]; P < 0.001) and neoadjuvant treatment (OR 0.09 [95% CI 0.01-0.68]; P = 0.02) were associated with recurrence <3 months. LogCA 19-9 (OR 1.23 [95% CI 1.10-1.38]; P < 0.001) and 0-90° venous involvement on CT imaging (OR 2.93 [95% CI 1.60-5.37]; P < 0.001) were associated with recurrence within 3-6 months. A Charlson Age Comorbidity Index ≥4 (OR 1.53 [95% CI 1.09-2.16]; P = 0.02) and logCA 19-9 (OR 1.24 [95% CI 1.14-1.35]; P < 0.001) were related to recurrence within 6-12 months. CONCLUSION: This study demonstrates preoperative predictors that are associated with the manifestation of early and very early recurrence after PDAC resection. Knowledge of these predictors can be used to guide individualized surveillance and treatment strategies.

Anatomic Criteria Determine Resectability in Locally Advanced Pancreatic Cancer.

BACKGROUND: The introduction of multi-agent chemotherapy and radiation therapy has facilitated potential resection with curative intent in selected locally advanced pancreatic cancer (LAPC) patients with excellent outcomes. Nevertheless, there remains a remarkable lack of consensus on the management of LAPC. We sought to describe the outcomes of patients with LAPC and objectively define the multidisciplinary selection process for operative exploration based on anatomical factors. METHODS: Consecutive patients with LAPC were evaluated for pancreatic surgery in the multidisciplinary clinic of a high-volume institution, between 2013 and 2018. Prospective stratification (LAPC-1, LAPC-2, and LAPC-3), based on the involvement of regional anatomical structures, was performed at the time of presentation prior to the initiation of treatment. Resection rates and patient outcomes were evaluated and correlated with the initial anatomic stratification system. RESULTS: Overall, 415 patients with LAPC were included in the study, of whom 84 (20%) were successfully resected, with a median overall survival of 35.3 months. The likelihood of operative exploration was associated with the pretreatment anatomic LAPC score, with a resection rate of 49% in patients classified as LAPC-1, 32% in LAPC-2, and 11% in LAPC-3 (p < 0.001). Resected patients with improvement of the LAPC score at the time of exploration had significantly longer median overall survival compared with those with no change or progression of LAPC score (60.7 vs. 29.8 months, p = 0.006). CONCLUSIONS: Selected patients with LAPC can undergo curative-intent surgery with excellent outcomes. The proposed Johns Hopkins anatomic LAPC score provides an objective system to anticipate the probability of eventual surgical resection after induction therapy.

Proclivity to Explore Locally Advanced Pancreas Cancer Is Not Associated with Surgeon Volume.

BACKGROUND AND PURPOSE: There is limited high-level evidence to guide locally advanced pancreas cancer (LAPC) management. Recent work shows that surgeons' preferences in LAPC management vary broadly. We sought to examine whether surgeon volume was associated with attitudes regarding LAPC management. METHODS: An electronic survey was distributed by email to an international cohort of pancreas surgeons to evaluate practice patterns regarding LAPC management. Clinical vignette-based questions evaluated surgeons' attitudes regarding patient eligibility and the proclivity to offer exploration. Surgeons were classified into "low-" or "high-volume" categories according to thresholds of self-reported annual pancreatectomy volume. Surgeon's attitudes regarding LAPC management and inclination to consider exploration were compared across annual volume categories. RESULTS: A total of 153 eligible responses were received from 4 continents, for an estimated response rate of 10.6%. Median duration of practice was 12 years (IQR 6-20). Most respondents reported >25 cases/year (89, 58.2%), of which 34 (22.2%) reported >50. Compared to surgeons with <25 cases/year, surgeons with >25 cases/year practiced longer (median 15 vs. 7.5 years, P<0.001) and were more likely to "always" recommend neoadjuvant chemotherapy (83.2% vs. 56.3%, P=0.001). Surgeons performing >50 cases/year were more likely to offer arterial resection (70.6% vs. 43.7%, P=0.006). The willingness to offer (or defer) exploration did not differ across any categories of surgeons' annual case volume. CONCLUSIONS: In an international survey of pancreas surgeons, the proclivity to consider exploration for LAPC was not associated with multiple categories of surgeon volume. Better evidence is needed to define the optimal management approach to LAPC.

Management of Locally Advanced Pancreatic Cancer: Results of an International Survey of Current Practice.

OBJECTIVE: The aim of this study was to investigate surgeon preferences for the management of patients with locally advanced pancreatic cancer (LAPC). BACKGROUND: Select patients with LAPC may become candidates for curative resection following neoadjuvant therapy, and recent reports of survival are encouraging. Yet the optimal management approach remains unclear. METHODS: An extensive electronic survey was systematically distributed by email to an international cohort of pancreas surgeons. Data collected included practice characteristics, management preferences, attitudes regarding contraindications to surgery, and 6 clinical vignettes of patients that ultimately received a margin negative resection (with detailed videos of post-neoadjuvant imaging) to assess propensity for surgical exploration if resection status is not known. RESULTS: A total of 153 eligible responses were received from 4 continents. Median duration of practice is 12 years (interquartile range 6-20) and 77% work in a university setting. Most surgeons (86%) are considered high volume (>10 resections/yr), 33% offer a minimally-invasive approach, and 50% offer arterial resections in select patients. Most (72%) always recommend neoadjuvant chemotherapy, and 65% prefer FOLFIRINOX. Preferences for the duration of chemotherapy varied widely: 39% prefer ≥2 months, 43% prefer ≥4 months, and 11% prefer ≥6 months. Forty-one percent frequently recommend neoadjuvant radiotherapy, and 53% prefer 5 to 6 weeks of chemoradiation. The proportion of surgeons favoring exploration following neoadjuvant varied extensively across 5 vignettes of LAPC, from 14% to 53%. In a vignette of oligometastatic liver metastases, 31% would offer exploration if a favorable therapy response is observed. CONCLUSIONS: In an international cohort of pancreas surgeons, there is substantial variation in management preferences, perceived contraindications to surgery, and the propensity to consider exploration in LAPC. These results emphasize the importance of a robust and nuanced multidisciplinary discussion for each patient, and suggest an evolving concept of "resectability."

Recurrence in Patients Achieving Pathological Complete Response After Neoadjuvant Treatment for Advanced Pancreatic Cancer.

OBJECTIVE: The aim of this study was to characterize the patterns and treatment of disease recurrence in patients achieving a pathological complete response (pCR) following neoadjuvant chemoradiation for advanced pancreatic ductal adenocarcinoma (PDAC). SUMMARY OF BACKGROUND DATA: A pCR is an independent predictor for improved survival in PDAC. However, disease recurrence is still observed in these patients. METHODS: Patients with advanced PDAC who were treated with neoadjuvant therapy and had a pCR were identified between 2009 and 2017. Overall survival (OS) was determined from the initiation of neoadjuvant, disease-free survival (DFS) from the date of surgery, and post-recurrence survival (PRS) from the date of recurrence. Factors associated with recurrence were analyzed using a Cox-regression model. RESULTS: Of 331 patients with borderline resectable or locally advanced PDAC, 30 achieved a pCR following neoadjuvant treatment and pancreatectomy. The median DFS for pCR patients was 29 months and OS 76 months. Recurrence was observed in 14 patients. No clinicopathologic or treatment characteristics were associated with survival. The median PRS following recurrence was 25 months. Treatment following recurrence included chemotherapy, radiation or ablation, and surgical resection. Hepatectomy or completion pancreatectomy was accomplished in 2 patients that remain alive 13 and 62 months, respectively, following metastasectomy. CONCLUSIONS: A pCR following neoadjuvant therapy in patients with advanced PDAC is associated with remarkable survival, although recurrence occurs in about half of patients. Nevertheless, patients with pCR and recurrence respond well to treatment and survival remains encouraging. Advanced molecular characterization and longitudinal liquid biopsy may offer additional assistance with understanding tumor biologic behavior after achieving a pCR.

Perioperative Outcomes of Robotic Pancreaticoduodenectomy: a Propensity-Matched Analysis to Open and Laparoscopic Pancreaticoduodenectomy.

INTRODUCTION: Robotic pancreaticoduodenectomy is slowly gaining acceptance within pancreatic surgery. Advantages have been demonstrated for robotic surgery in other fields, but robust data for pancreaticoduodenectomy is limited. The aim of this study was to compare the short-term outcomes of robotic pancreaticoduodenectomy (RPD) to open pancreaticoduodenectomy (OPD) and laparoscopic pancreaticoduodenectomy (LPD). METHODS: Patients who underwent a pancreaticoduodenectomy between January 2011 and July 2019 at the Johns Hopkins Hospital were included in this retrospective propensity-matched analysis. The RPD cohort was matched to patients who underwent OPD in a 1:2 fashion and LPD in a 1:1 fashion. Short-term outcomes were analyzed for all three cohorts. RESULTS: In total, 1644 patients were included, of which 96 (5.8%) underwent RPD, 131 (8.0%) LPD, and 1417 (86.2%) OPD. RPD was associated with a decreased incidence of delayed gastric emptying (9.4%) compared to OPD (23.5%; P = 0.006). The median estimated blood loss was significantly less in the RPD cohort (RPD vs OPD, 150 vs 487 mL; P < 0.001, RPD vs LPD, 125 vs 300 mL; P < 0.001). Compared to OPD, the robotic approach was associated with a shorter median length of stay (median 8 vs 9 days; P = 0.014) and a decrease in wound complications (4.2% vs 16.7%; P = 0.002). The incidence of other postoperative complications was comparable between RPD and OPD, and RPD and LPD. CONCLUSION: In the hands of experienced surgeons, RPD may have a modest yet statistically significant reduction in estimated blood loss, postoperative length of stay, wound complications, and delayed gastric emptying comparing to OPD in similar patients.

Pancreatic circulating tumor cell detection by targeted single-cell next-generation sequencing.

BACKGROUND AND AIMS: Single-cell next-generation sequencing (scNGS) technology has been widely used in genomic profiling, which relies on whole-genome amplification (WGA). However, WGA introduces errors and is especially less accurate when applied to single nucleotide variant (SNV) analysis. Targeted scNGS for SNV without WGA has not been described. We aimed to develop a method to detect circulating tumor cells (CTCs) with DNA SNVs. METHODS: We tested this targeted scNGS method with three driver mutant genes (KRAS/TP53/SMAD4) on one pancreatic cancer cell line AsPC-1 and then applied it to patients with metastatic PDAC for the validation. RESULTS: All single-cell of AsPC-1 and spiked-in AsPC-1 cells in healthy donor blood, which were isolated by the filtration with size or by flow cytometry, were detected by targeted scNGS method. All blood samples from six patients with metastatic PDAC, for the validation of target scNGS method, showed CTCs with SNVs of KRAS/TP53/SMAD4 and the positive confirmation of immunofluorescent stainings with Pan-CK/Vimentin/CD45. Four patients with early stage disease, one patient with benign pancreatic cyst and a healthy control sample all showed concordant results between targeted scNGS and CTC enumeration. CONCLUSIONS: The novel technique of targeted scNGS for SNV analysis, without pre-amplification, is a promising method for identifying and characterizing circulating tumor cells.

Pattern of Invasion in Human Pancreatic Cancer Organoids Is Associated with Loss of SMAD4 and Clinical Outcome.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy characterized by extensive local invasion and systemic spread. In this study, we employed a three-dimensional organoid model of human pancreatic cancer to characterize the molecular alterations critical for invasion. Time-lapse microscopy was used to observe invasion in organoids from 25 surgically resected human PDAC samples in collagen I. Subsequent lentiviral modification and small-molecule inhibitors were used to investigate the molecular programs underlying invasion in PDAC organoids. When cultured in collagen I, PDAC organoids exhibited two distinct, morphologically defined invasive phenotypes, mesenchymal and collective. Each individual PDAC gave rise to organoids with a predominant phenotype, and PDAC that generated organoids with predominantly mesenchymal invasion showed a worse prognosis. Collective invasion predominated in organoids from cancers with somatic mutations in the driver gene SMAD4 (or its signaling partner TGFBR2). Reexpression of SMAD4 abrogated the collective invasion phenotype in SMAD4-mutant PDAC organoids, indicating that SMAD4 loss is required for collective invasion in PDAC organoids. Surprisingly, invasion in passaged SMAD4-mutant PDAC organoids required exogenous TGFß, suggesting that invasion in SMAD4-mutant organoids is mediated through noncanonical TGFß signaling. The Rho-like GTPases RAC1 and CDC42 acted as potential mediators of TGFß-stimulated invasion in SMAD4-mutant PDAC organoids, as inhibition of these GTPases suppressed collective invasion in our model. These data suggest that PDAC utilizes different invasion programs depending on SMAD4 status, with collective invasion uniquely present in PDAC with SMAD4 loss. SIGNIFICANCE: Organoid models of PDAC highlight the importance of SMAD4 loss in invasion, demonstrating that invasion programs in SMAD4-mutant and SMAD4 wild-type tumors are different in both morphology and molecular mechanism.