Transfer Learning Reveals Cancer-Associated Fibroblasts Are Associated with Epithelial-Mesenchymal Transition and Inflammation in Cancer Cells in Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy characterized by an immunosuppressive tumor microenvironment enriched with cancer-associated fibroblasts (CAF). This study used a convergence approach to identify tumor cell and CAF interactions through the integration of single-cell data from human tumors with human organoid coculture experiments. Analysis of a comprehensive atlas of PDAC single-cell RNA sequencing data indicated that CAF density is associated with increased inflammation and epithelial-mesenchymal transition (EMT) in epithelial cells. Transfer learning using transcriptional data from patient-derived organoid and CAF cocultures provided in silico validation of CAF induction of inflammatory and EMT epithelial cell states. Further experimental validation in cocultures demonstrated integrin beta 1 (ITGB1) and vascular endothelial factor A (VEGFA) interactions with neuropilin-1 mediating CAF-epithelial cell cross-talk. Together, this study introduces transfer learning from human single-cell data to organoid coculture analyses for experimental validation of discoveries of cell-cell cross-talk and identifies fibroblast-mediated regulation of EMT and inflammation.

SIGNIFICANCE

Adaptation of transfer learning to relate human single-cell RNA sequencing data to organoid-CAF cocultures facilitates discovery of human pancreatic cancer intercellular interactions and uncovers cross-talk between CAFs and tumor cells through VEGFA and ITGB1.

Mesothelin CAR T Cells Secreting Anti-FAP/Anti-CD3 Molecules Efficiently Target Pancreatic Adenocarcinoma and its Stroma

PURPOSE

Targeting solid tumors with chimeric antigen receptor (CAR) T cells remains challenging due to heterogenous target antigen expression, antigen escape, and the immunosuppressive tumor microenvironment (TME). Pancreatic cancer is characterized by a thick stroma generated by cancer-associated fibroblasts (CAF), which may contribute to the limited efficacy of mesothelin-directed CAR T cells in early-phase clinical trials. To provide a more favorable TME for CAR T cells to target pancreatic ductal adenocarcinoma (PDAC), we generated T cells with an antimesothelin CAR and a secreted T-cell-engaging molecule (TEAM) that targets CAF through fibroblast activation protein (FAP) and engages T cells through CD3 (termed mesoFAP CAR-TEAM cells).

EXPERIMENTAL DESIGN

Using a suite of in vitro, in vivo, and ex vivo patient-derived models containing cancer cells and CAF, we examined the ability of mesoFAP CAR-TEAM cells to target PDAC cells and CAF within the TME. We developed and used patient-derived ex vivo models, including patient-derived organoids with patient-matched CAF and patient-derived organotypic tumor spheroids.

RESULTS

We demonstrated specific and significant binding of the TEAM to its respective antigens (CD3 and FAP) when released from mesothelin-targeting CAR T cells, leading to T-cell activation and cytotoxicity of the target cell. MesoFAP CAR-TEAM cells were superior in eliminating PDAC and CAF compared with T cells engineered to target either antigen alone in our ex vivo patient-derived models and in mouse models of PDAC with primary or metastatic liver tumors.

CONCLUSIONS

CAR-TEAM cells enable modification of tumor stroma, leading to increased elimination of PDAC tumors. This approach represents a promising treatment option for pancreatic cancer.

Exploring the Clinical Use of Molecular Profiling of Intrahepatic Cholangiocarcinoma in a Comprehensive Multidisciplinary Clinic

BACKGROUND

Molecular profiling of intrahepatic cholangiocarcinoma (ICC) can detect actionable molecular alterations and guide targeted therapies. We explore the clinical use of molecular profiling of ICC in our comprehensive multidisciplinary clinic.

STUDY DESIGN

Patients with a tissue diagnosis of ICC seen between 2019 and 2023 were identified. A retrospective review was performed to identify their molecular profiles and targeted therapy. The association between the detection of actionable molecular alterations and overall survival (OS) from the first clinic visit date was studied. Patients with an OS of less than 2 months were excluded.

RESULTS

Among 194 patients with ICC, 125 had molecular profiling. Actionable molecular alterations were detected in 56 (45%) patients, including microsatellite instability (n = 3), high tumor mutational burden (>10 muts/mb; n = 5), isocitrate dehydrogenase 1 and 2 mutations (n = 22 and 6, respectively), BRAF V600E mutations (n = 2), phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha mutations (n = 7), breast cancer 1 and breast cancer 2 mutations (n = 5), mesenchymal epithelial transition amplification (n = 2), fibroblast growth factor receptor 2 and 3 fusions (n = 13), erb-b2 receptor tyrosine kinase 2 overexpression (n = 6), and receptor tyrosine kinase 1 fusion (n = 1). Twenty-one patients received targeted therapies during their treatment course. Survival analysis revealed that for 120 patients with molecular profiling, the detection of an actionable molecular alteration was associated with improved mean OS (34.1 vs 23.6 months, p = 0.008). Among 70 patients with nonmetastatic ICC, the detection of an actionable molecular alteration was associated with improved mean OS (32.1 vs 27.5 months, p = 0.02).

CONCLUSIONS

Actionable molecular alterations were frequently observed in patients with ICC. Detection of actionable alterations was associated with improved OS. The role of targeted therapy needs further exploration in prospective multicenter studies.

Using Tumor Marker Gene Variants to Improve the Diagnostic Accuracy of DUPAN-2 and Carbohydrate Antigen 19-9 for Pancreatic Cancer

PURPOSE

Circulating carbohydrate antigen 19-9 (CA19-9) levels reflect FUT3 and FUT2 fucosyltransferase activity. Measuring the related glycan, DUPAN-2, can be useful in individuals unable to synthesize CA19-9. We hypothesized that similar to CA19-9, FUT functional groups determined by variants in FUT3 and FUT2 influence DUPAN-2 levels, and having tumor marker reference ranges for each functional group would improve diagnostic performance.

MATERIALS AND METHODS

Using a training/validation study design, FUT2/FUT3 genotypes were determined in 938 individuals from Johns Hopkins Hospital: 607 Cancer of the Pancreas Screening (CAPS) study subjects with unremarkable pancreata and 331 with pancreatic ductal adenocarcinoma (PDAC). Serum DUPAN-2 and CA19-9 levels were measured by immunoassay.

RESULTS

In controls, three functional FUT groups were identified with significant differences in DUPAN-2 levels: FUT3-intact, FUT3-null/FUT2-intact, and FUT3-null/FUT2-null. DUPAN-2 training set diagnostic cutoffs for each FUT group yielded higher diagnostic sensitivity in the validation set for patients with stage I/II PDAC than uniform cutoffs (60.4% [95% CI, 50.2 to 70.0] v 39.8% [30.0 to 49.8]), at approximately 99% (96.7 to 99.6) specificity. Combining FUT/CA19-9 and FUT/DUPAN-2 tests yielded 78.4% (72.3 to 83.7) sensitivity for stage I/II PDAC, at 97.7% (95.3 to 99.1) specificity in the combined sets, with higher AUC (stage I/II: 0.960 v 0.935 for CA19-9 + DUPAN-2 without the FUT test; P < .001); for stage I PDAC, sensitivity was 62.0% (49.1 to 73.2; AUC, 0.919 v 0.883; P = .03). CA19-9 levels in FUT3-null/FUT2-null PDAC subjects were higher than in FUT3-null/FUT2-intact subjects (median/IQR; 24.9/57.4 v <1/2.3 U/mL; P = .0044). In a simulated CAPS cohort, AUC precision recall (AUCPR) scores were 0.51 for CA19-9 alone, 0.64 for FUT/CA19-9, 0.73 for CA19-9/DUPAN-2, and 0.84 for FUT/CA19-9/DUPAN-2.

CONCLUSION

Using a tumor marker gene test to individualize CA19-9 and DUPAN-2 reference ranges achieves high diagnostic performance for stage I/II pancreatic cancer.

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.

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.

Oncologic resection of pancreatic cancer with isolated liver metastasis: Favorable outcomes in select patients

BACKGROUND

Patients with pancreatic ductal adenocarcinoma (PDAC) and liver metastasis are treated with palliative chemotherapy, whereas similar patients with metastatic colorectal cancer are considered for aggressive surgery.

METHODS

Using an institutional database, PDAC patients undergoing liver resection for isolated metastasis were identified. Their overall survival (OS), treatment factors, and clinicopathological variables associated with survival were also evaluated.

RESULTS

Forty-seven patients underwent curative-intent surgery for metastatic PDAC to the liver between 2000 and 2019. Median OS was 21.9 months from diagnosis. Fourteen patients underwent unplanned resection of radiographically occult liver metastasis during pancreatectomy with median OS of 8.7 months. On the other hand, 29 patients received systemic chemotherapy followed by planned resection; this cohort had the most favorable prognosis following aggressive surgery with median OS being 38.1 months from diagnosis and 24.1 months from surgery. Preoperative chemotherapy (HR = 7.1; p = .002) and moderate to well differentiation of the primary tumor (HR = 3.7; p = .003) were associated with prolonged survival in multivariate analysis, whereas lymph node metastases, response to preoperative therapy, number of liver metastasis, and extent of liver surgery were not.

CONCLUSIONS

In select patients with PDAC and isolated liver metastasis, curative-intent surgery can result in meaningful survival. This aggressive approach seems most beneficial in patients following induction chemotherapy.

Conduits in Vascular Pancreatic Surgery: Analysis of Clinical Outcomes, Operative Techniques, and Graft Performance

OBJECTIVES

We analyze successes and failures of pushing the boundaries in vascular pancreatic surgery to establish safety of conduit reconstructions.

BACKGROUND

Improved systemic control from chemotherapy in pancreatic cancer is increasing the demand for surgical solutions of extensive local vessel involvement, but conduit-specific data are scarce.

METHODS

We identified 63 implanted conduits (41% autologous vessels, 37% allografts, 18% PTFE) in 56 pancreatic resections of highly selected cancer patients between October 2013 and July 2020 from our prospectively maintained database. Assessed parameters were survival, perioperative complications, operative techniques (anatomic and extra-anatomic routes), and conduit patency.

RESULTS

For vascular reconstruction, 25 arterial and 38 venous conduits were utilized during 39 pancreatoduodenectomies, 14 distal pancreatectomies, and 3 total pancreatectomies. The median postoperative survival was 2 years. A Clavien-Dindo grade ≥IIIa complication was apparent in 50% of the patients with a median Comprehensive Complication Index of 29.6. The 90-day mortality in this highly selected cohort was 9%. Causes of mortality were conduit related in 3 patients, late postpancreatectomy hemorrhage in 1 patient, and early liver metastasis in 1 patient. Image-based patency rates of conduits were 66% and 45% at postoperative days 30 and 90, respectively.

CONCLUSIONS

Our perioperative mortality of vascular pancreatic surgery with conduits in the arterial or venous system is 9%. Reconstructions are technically feasible with different anatomic and extra-anatomic strategies, while identifying predictors of early conduit occlusion remains challenging. Optimizing reconstructed arterial and venous hemodynamics in the context of pancreatic malignancy will enable long-term survival in more patients responsive to chemotherapies.

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.

Persistent Circulating Tumor Cells at 1 Year After Oncologic Resection Predict Late Recurrence in Pancreatic Cancer

OBJECTIVE

The aim of the study was to assess the association between persistent circulating tumor cells (CTCs) and subsequent recurrence in patients who were clinically recurrence free ~12 months postoperatively.

BACKGROUND

Circulating tumor cells have been proposed as biomarkers to predict survival in pancreatic cancer. Some patients demonstrate persistent CTCs postoperatively, which could represent minimal residual disease.

METHODS

Patients from previously published prospective circulating tumor cell in pancreatic cancer trial without clinical evidence of recurrence 12 months postoperatively and CTC testing performed 9 to 15 months postoperatively were included. The presence of epithelial and transitional CTCs (trCTCs) was evaluated as predictor of recurrence. Kaplan-Meier curve, log-rank test, and Cox model were used for survival analysis.

RESULTS

Thirty-three of 129 eligible patients (circulating tumor cell in pancreatic cancer trial) were included. The trCTC-positive and negative patients were well balanced in clinicopathologic features. Patients with trCTCs had a recurrence rate per-person-month of 10.3% compared with 3.1% in trCTCs-negative patients with a median time to recurrence of 3.9 versus 27.1 months, respectively. On multivariable analysis, trCTCs positivity was associated with higher risk of late recurrence (hazard ratio: 4.7, 95% CI, 1.2-18.3, P =0.024). Fourteen (42.4%) patients recurred during the second postoperative year. One-year postoperative trCTCs positivity was associated with a higher rate of recurrence during the second year (odds ratio:13.1, 95% CI, 1.6-1953.4, P =0.028, area under curve=0.72). Integrating clinicopathologic features with trCTCs increased the area under curve to 0.80. A majority of trCTCs-positive patients (N=5, 62.5%) had multisite recurrence, followed by local-only (N=2, 25.0%) and liver-only (N=1, 12.5%) recurrence. This was in striking contrast to trCTCs-negative patients, where a majority (N=6, 66.7%) had a local-only recurrence, followed by liver-only (N=2, 22.2%) and multisite (N=1, 11.1%) recurrence.

CONCLUSIONS

In patients deemed to be clinically disease-free 12 months postoperatively, trCTCs positivity is associated with higher rates of subsequent recurrence with distinct patterns of recurrence. CTCs could be used a putative biomarker to guide patient prognostication and management in pancreatic cancer.

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.

Hereditary colorectal, gastric, and pancreatic cancer: comprehensive review

BACKGROUND

Inheritance patterns show familial clustering of gastrointestinal cancers, and multiple germline conditions have now been identified that predispose to colorectal, gastric, and pancreatic cancers.

METHODS

A narrative review based on recent relevant literature was conducted.

RESULTS

Lynch syndrome, formerly known as hereditary non-polyposis colorectal cancer, increases the risk of several abdominal cancers, with the highest population prevalence. Familial adenomatous polyposis and some of the more infrequent polyposis syndromes have distinct characteristics affecting various organ-specific cancer risks. Hereditary gastric and pancreatic cancer syndromes include those also causing colorectal cancer, while additional genetic disorders predisposing only to upper gastrointestinal malignancies have been recognized more recently. Diagnosing and managing hereditary cancer syndromes requires multidisciplinary expertise and may be best managed in tertiary centres, with a need to consider patient preference and ensure shared decision-making.

CONCLUSION

Several germline conditions predispose to colorectal, gastric, and pancreatic cancer, which inform identification, surveillance regimens, prevention, cascade screening, counselling, and surgical management. The authors describe developments in the hereditary origin of colorectal, gastric, and pancreatic cancer with current recommendations in surveillance and surgical management.

Tailoring Adjuvant Chemotherapy to Biologic Response Following Neoadjuvant Chemotherapy Impacts Overall Survival in Pancreatic Cancer

BACKGROUND

The role of postoperative chemotherapy in patients with resected pancreatic cancer who receive neoadjuvant treatment is unknown. Clinicians use changes in CA19-9 and histopathologic scores to assess treatment response. We sought to investigate if CA19-9 normalization in response to NAT can help guide the need for postoperative treatment.

METHODS

Patients with elevated baseline CA19-9 (CA19-9 > 37U/mL) who received NAT followed by surgery between 2011 and 2019 were retrospectively reviewed. Treatment response was determined by CA19-9 normalization following NAT and histopathologic scoring. The role of postoperative chemotherapy was analyzed in light of CA19-9 normalization and histopathologic response.

RESULTS

We identified and included 345 patients. Following NAT, CA19-9 normalization was observed in 125 patients (36.2%). CA19-9 normalization was associated with a favorable histopathologic response (41.6% vs 23.2%, p < 0.001) and a lower ypT (p < 0.001) and ypN stage (p = 0.003). Receipt of adjuvant chemotherapy was associated with improved overall survival in patients in whom CA19-9 did not normalize following NAT (26.8 vs 16.4 months, p = 0.008). In patients who received 5FU-based NAT and in whom CA19-9 did not normalize, receipt of 5FU-based adjuvant chemotherapy was associated with improved OS (p = 0.014).

CONCLUSION

CA19-9 normalization in response to NAT was associated with favorable outcomes and can serve as a biomarker for treatment response. In patients where CA19-9 did not normalize, receipt of postoperative chemotherapy was associated with improved OS. These patients also benefited from additional 5FU-based postoperative chemotherapy following 5FU-based NAT.

Cancer-cell-derived sialylated IgG as a novel biomarker for predicting poor pathological response to neoadjuvant therapy and prognosis in pancreatic cancer

BACKGROUND

Neoadjuvant therapy (NAT) is increasingly applied in pancreatic ductal adenocarcinoma (PDAC); however, accurate prediction of therapeutic response to NAT remains a pressing clinical challenge. Cancer-cell-derived sialylated immunoglobulin G (SIA-IgG) was previously identified as a prognostic biomarker in PDAC. This study aims to explore whether SIA-IgG expression in treatment-naïve fine needle aspirate (FNA) biopsy specimens could predict the pathological response (PR) to NAT for PDAC.

METHODS

Endoscopic ultrasonography-guided FNA biopsy specimens prior to NAT were prospectively obtained from 72 patients with PDAC at the Johns Hopkins Hospital. SIA-IgG expression of PDAC specimens was assessed by immunohistochemistry. Associations between SIA-IgG expression and PR, as well as patient prognosis, were analyzed. A second cohort enrolling surgically resected primary tumor specimens from 79 patients with PDAC was used to validate the prognostic value of SIA-IgG expression.

RESULTS

SIA-IgG was expressed in 58.3% of treatment-naïve FNA biopsies. Positive SIA-IgG expression at diagnosis was associated with unfavorable PR and can serve as an independent predictor of PR. The sensitivity and specificity of SIA-IgG expression in FNA specimens in predicting an unfavorable PR were 63.9% and 80.6%, respectively. Both positive SIA-IgG expression in treatment-naïve FNA specimens and high SIA-IgG expression in surgically resected primary tumor specimens were significantly associated with shorter survival.

CONCLUSIONS

Assessment of SIA-IgG on FNA specimens prior to NAT may help predict PR for PDAC. Additionally, SIA-IgG expression in treatment-naïve FNA specimens and surgically resected primary tumor specimens were predictive of the prognosis for PDAC.

A multicenter, randomized phase II study of total neoadjuvant therapy (TNT) with FOLFIRINOX (FFX) and SBRT, with or without losartan (L) and nivolumab (N) in borderline resectable (BR) and locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC)

719

Background: Outcomes in BR and LA PDAC remain historically poor, in part due to low rates of R0 resection. A prior phase II study demonstrated that losartan (L) as a TGF-beta inhibitor combined with FOLFIRINOX (FFX) and radiation in LA PDAC led to a 61% R0 resection rate. Additionally, prior phase II studies suggest potential synergy with SBRT and nivolumab (N) in PDAC. We conducted a multi-center, randomized phase II trial to evaluate the effect of L and L+N in combination with TNT using FFX and SBRT. Methods: Patients with BR or LA PDAC by NCCN criteria, pathologically confirmed, ACE/ARB naïve, were randomized to TNT with FFX and SBRT (Arm 1), TNT + L (Arm 2), and TNT+L+N (Arm 3), stratified by BR/LA. Patients already on an ACE or ARB were enrolled on an exploratory arm of TNT+N (Arm 4) and will be reported separately. TNT consisted of FFX x 8 followed by SBRT (6.6 Gy x 5). L was given at 50 mg qd throughout TNT and for 6 mo after surgery. N was given at 240 mg flat dosing q2 wks concurrent with SBRT and for 12 doses postoperatively. All patients were recommended for surgical exploration after TNT. The study was designed to compare the R0 resection rate on each of Arms 2 and 3 independently versus Arm 1 at a one-sided 0.10 level. Secondary endpoints were PFS, OS, and pCR rates and analyzed using two-sided tests with Arm 1 as the control arm. Intent-to-treat analysis was based on eligible patients who started therapy on protocol. Results: Patients with BR or LA PDAC by NCCN criteria, pathologically confirmed, ACE/ARB naïve, were randomized to TNT with FFX and SBRT (Arm 1), TNT + L (Arm 2), and TNT+L+N (Arm 3), stratified by BR/LA. Patients already on an ACE or ARB were enrolled on an exploratory arm of TNT+N (Arm 4) and will be reported separately. TNT consisted of FFX x 8 followed by SBRT (6.6 Gy x 5). L was given at 50 mg qd throughout TNT and for 6 mo after surgery. N was given at 240 mg flat dosing q2 wks concurrent with SBRT and for 12 doses postoperatively. All patients were recommended for surgical exploration after TNT. The study was designed to compare the R0 resection rate on each of Arms 2 and 3 independently versus Arm 1 at a one-sided 0.10 level. Secondary endpoints were PFS, OS, and pCR rates and analyzed using two-sided tests with Arm 1 as the control arm. Intent-to-treat analysis was based on eligible patients who started therapy on protocol. Conclusions: We did not observe effects of L and L+N on the R0 resection rate, PFS, OS, and pCR rate when added to TNT with FFX and SBRT for BR or LA PDAC. The lack of differences may reflect heterogeneity in surgical opinion as the decision for proceeding to surgery following TNT tends to be highly variable in a population with historically low resection rates. Clinical trial information: NCT03563248 .

Surgical Decision-Making in Pancreatic Ductal Adenocarcinoma: Modeling Prognosis Following Pancreatectomy in the Era of Induction and Neoadjuvant Chemotherapy

OBJECTIVE

To develop a predictive model of oncologic outcomes for patients with pancreatic ductal adenocarcinoma (PDAC) undergoing resection after neoadjuvant or induction chemotherapy use.

BACKGROUND

Early recurrence following surgical resection for PDAC is common. The use of neoadjuvant chemotherapy prior to resection may increase the likelihood of long-term systemic disease control. Accurately characterizing an individual's likely oncologic outcome in the perioperative setting remains challenging.

METHODS

Data from patients with PDAC who received chemotherapy prior to pancreatectomy at a single high-volume institution between 2007 and 2018 were captured in a prospectively collected database. Core clinicopathologic data were reviewed for accuracy and survival data were abstracted from the electronic medical record and national databases. Cox-proportional regressions were used to model outcomes and develop an interactive prognostic tool for clinical decision-making.

RESULTS

A total of 581 patients were included with a median overall survival (OS) and recurrence-free survival (RFS) of 29.5 (26.5-32.5) and 16.6 (15.8-17.5) months, respectively. Multivariable analysis demonstrates OS and RFS were associated with type of chemotherapeutic used andthe number of chemotherapy cycles received preoperatively. Additional factors contributing to survival models included: tumor grade, histopathologic response to therapy, nodal status, and administration of adjuvant chemotherapy. The models were validated using an iterative bootstrap method and with randomized cohort splitting. The models were well calibrated with concordance indices of 0.68 and 0.65 for the final OS and RFS models, respectively.

CONCLUSION

We developed an intuitive and dynamic decision-making tool that can be useful in estimating OS, RFS, and location-specific disease recurrence rates. This prognostic tool may add value to patient care in discussing the benefits associated with surgical resection for PDAC.

Impact of the COVID-19 Pandemic on Liver Cancer Staging at a Multidisciplinary Liver Cancer Clinic

To compare liver cancer resectability rates before and during the COVID-19 pandemic.

Background

Liver cancers usually present with nonspecific symptoms or are diagnosed through screening programs for at-risk patients, and early detection can improve patient outcomes. In 2020, the COVID-19 pandemic upended medical care across all specialties, but whether the pandemic was associated with delays in liver cancer diagnosis is not known.

Methods

We performed a retrospective review of all patients evaluated at the Johns Hopkins Multidisciplinary Liver Cancer Clinic from January 2019 to June 2021 with a new diagnosis of suspected or confirmed hepatocellular carcinoma (HCC) or biliary tract cancer (BTC).

Results

There were 456 liver cancer patients (258 HCC and 198 BTC). From January 2019 to March 2020 (pre-pandemic), the surgical resectability rate was 20%. The subsequent 6 months (early pandemic), the resectability rate decreased to 11%. Afterward from October 2020 to June 2021 (late pandemic), the resectability rate increased to 27%. The resectability rate early pandemic was significantly lower than that for pre-pandemic and later pandemic combined (11% lower; 95% confidence interval [CI], 2%-20%). There was no significant difference in resectability rates pre-pandemic and later pandemic (7% difference; 95% CI, -3% to 16%). In subgroup analyses, the early pandemic was associated with a larger impact in BTC resectability rates than HCC resectability rates. Time from BTC symptom onset until Multidisciplinary Liver Clinic evaluation increased by over 6 weeks early pandemic versus pre-pandemic (Hazard Ratio, 0.63; 95% CI, 0.44-0.91).

Conclusions

During the early COVID-19 pandemic, we observed a drop in the percentage of patients presenting with curable liver cancers. This may reflect delays in liver cancer diagnosis and contribute to excess mortality related to the COVID-19 pandemic.

Postoperative Chemotherapy is Associated with Improved Survival in Patients with Node-Positive Pancreatic Ductal Adenocarcinoma After Neoadjuvant Therapy

BACKGROUND

Postoperative chemotherapy following pancreatic cancer resection is the standard of care. The utility of postoperative chemotherapy for patients who receive neoadjuvant therapy (NAT) is unclear.

METHODS

Patients who underwent pancreatectomy after NAT with FOLFIRINOX or gemcitabine-based chemotherapy for non-metastatic pancreatic adenocarcinoma (2015-2019) were identified. Patients who received less than 2 months of neoadjuvant chemotherapy or died within 90 days from surgery were excluded.

RESULTS

A total of 427 patients (resectable, 22.2%; borderline resectable, 37.9%; locally advanced, 39.8%) were identified with the majority (69.3%) receiving neoadjuvant FOLFIRINOX. Median duration of NAT was 4.1 months. Following resection, postoperative chemotherapy was associated with an improved median overall survival (OS) (28.7 vs. 20.4 months, P = 0.006). Risk-adjusted multivariable modeling showed negative nodal status (N0), favorable pathologic response (College of American Pathologists score 0 & 1), and receipt of postoperative chemotherapy to be independent predictors of improved OS. Regimen, duration, and number of cycles of NAT were not significant predictors. Thirty-four percent (60/176) of node-positive and 50.1% (126/251) of node-negative patients did not receive postoperative chemotherapy due to poor functional status, postoperative complications, and patient preference. Among patients with node-positive disease, postoperative chemotherapy was associated with improved median OS (27.2 vs. 10.5 months, P < 0.001). Among node-negative patients, postoperative chemotherapy was not associated with a survival benefit (median OS, 30.9 vs. 36.9 months; P = 0.406).

CONCLUSION

Although there is no standard NAT regimen for patients with pancreatic cancer, postoperative chemotherapy following NAT and resection appears to be associated with improved OS for patients with node-positive disease.

Precision Medicine in Pancreatic Cancer: Patient-Derived Organoid Pharmacotyping Is a Predictive Biomarker of Clinical Treatment Response

PURPOSE

Patient-derived organoids (PDO) are a promising technology to support precision medicine initiatives for patients with pancreatic ductal adenocarcinoma (PDAC). PDOs may improve clinical next-generation sequencing (NGS) and enable rapid ex vivo chemotherapeutic screening (pharmacotyping).

EXPERIMENTAL DESIGN

PDOs were derived from tissues obtained during surgical resection and endoscopic biopsies and studied with NGS and pharmacotyping. PDO-specific pharmacotype is assessed prospectively as a predictive biomarker of clinical therapeutic response by leveraging data from a randomized controlled clinical trial.

RESULTS

Clinical sequencing pipelines often fail to detect PDAC-associated somatic mutations in surgical specimens that demonstrate a good pathologic response to previously administered chemotherapy. Sequencing the PDOs derived from these surgical specimens, after biomass expansion, improves the detection of somatic mutations and enables quantification of copy number variants. The detection of clinically relevant mutations and structural variants is improved following PDO biomass expansion. On clinical trial, PDOs were derived from biopsies of treatment-naïve patients prior to treatment with FOLFIRINOX (FFX). Ex vivo PDO pharmacotyping with FFX components predicted clinical therapeutic response in these patients with borderline resectable or locally advanced PDAC treated in a neoadjuvant or induction paradigm. PDO pharmacotypes suggesting sensitivity to FFX components were associated with longitudinal declines of tumor marker, carbohydrate-antigen 19-9 (CA-19-9), and favorable RECIST imaging response.

CONCLUSIONS

PDOs established from tissues obtained from patients previously receiving cytotoxic chemotherapies can be accomplished in a clinically certified laboratory. Sequencing PDOs following biomass expansion improves clinical sequencing quality. High in vitro sensitivity to standard-of-care chemotherapeutics predicts good clinical response to systemic chemotherapy in PDAC. See related commentary by Zhang et al., p. 3176.

Abstract 1480: miR-21 as a post-transcriptional regulator of pancreatic ductal adenocarcinoma (PDAC) tumorigenesis

Introduction: MicroRNAs are short non-coding RNAs that are frequently dysregulated across cancers. Specifically, microRNA-21 (miR-21) is a known oncomir overexpressed in pancreatic adenocarcinoma (PDAC) that regulates multiple gene targets downstream of KRAS, the site of the primary driver mutation in PDAC. Past efforts to target mutant KRAS have been limited by compensatory activation of other growth pathways and treatment-related toxicity. Inhibiting miR-21 expression is a novel therapeutic strategy to target KRAS effector function through post-transcriptional regulation. We previously demonstrated that systemic inhibition of miRNA-21 (miR-21) intercepts tumorigenesis in the transgenic KrasG12D/+;Trp53R172H/+;Pdx-1-Cre (KPC) mice without causing overt toxicity. Our major goal was to verify the translation of the previous findings to human models and examine the mechanistic implications of miR-21 inhibition in PDAC.

Experimental Procedures: Using publicly available data from a cohort of patients with PDAC in The Cancer Genome Atlas (TCGA), we performed differential expression analysis of miR-21 and KRAS-related gene targets as well as gene set enrichment analysis of oncogenic pathways identified by the Molecular Signatures Database (MSigDB). Concurrently, de-novo patient-derived organoid (PDO) models were generated from core biopsies and surgical resection specimens. To evaluate the effects of miR-21 inhibition on KRAS pathway activity in a human model system, we selected 6 PDO cell lines and determined miR-21 gene expression by quantitative PCR at baseline and after knockdown using a lentiviral construct.

Results: Analysis of TCGA PDAC cohort identified heterogeneous endogenous expression of miR-21, which was validated ex vivo in our PDO model system. Gene set enrichment analysis revealed enrichment of gene sets associated with KRAS dependency, MEK, AKT, and MTOR signaling in patients with higher endogenous miR-21 expression. MiR-21 knockdown in PDO cell lines was stable at multiple intervals following lentiviral transduction. Further, expression of PDCD4, a tumor suppressor gene and target of miR-21 downstream of KRAS, was enhanced in PDO lines following miR-21 inhibition.

Conclusions: We previously demonstrated that miR-21 appears to be an early and reliable molecular marker of pancreatic neoplasia and that systemic inhibition in a murine model intercepts PDAC tumorigenesis. We now demonstrate in human models that higher miR-21 expression is associated with enrichment of gene sets downstream of KRAS. Additionally, knocking down miR-21 expression enhances the expression of gene targets with tumor suppressor function, notably PDCD4. This suggests that modulating miR-21 expression subsequently modulates the expression of gene targets with critical cell regulatory functions and provides additional insight into novel therapeutic targets.

Citation Format: Jacquelyn W. Zimmerman, Daniel H. Shu, Richard A. Burkhart, Joseph Tandurella, Elana J. Fertig, Elizabeth M. Jaffee. miR-21 as a post-transcriptional regulator of pancreatic ductal adenocarcinoma (PDAC) tumorigenesis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1480.

Trial in progress: A randomized phase II study of pembrolizumab with or without defactinib, a focal adhesion kinase inhibitor, following chemotherapy as a neoadjuvant and adjuvant treatment for resectable pancreatic ductal adenocarcinoma (PDAC)

TPS4192

Background: PDAC is an aggressive cancer. It remains refractory to checkpoint inhibition because of its significant desmoplastic and immunosuppressive tumor microenvironment (TME). Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, is involved in tumor progression in many cancers and appears to be a targetable master regulator of the TME in PDAC. FAK inhibition combined with anti-PD1 antibody has been shown to modulate pancreatic stellate cells and decrease immunosuppressive myeloid and T-reg cells, leading to increased CD8 infiltration and improved survival in PDAC mouse models. A recent single arm phase I study of defactinib, a FAK inhibitor, combined with pembrolizumab, an anti-PD1 antibody, and chemotherapy was shown to be safe, and two confirmed partial responses were observed in patients with microsatellite-stable disease. Furthermore, increased CD8 T cell infiltration was observed in metastatic biopsies. Given the promising preclinical data and efficacy signals, as well as safety of the phase I clinical trial, our current study aims to assess the translational and clinical effects of sequentially combined defactinib and pembrolizumab following neoadjuvant and adjuvant chemotherapy in patients with high-risk resectable PDAC. Methods: This study is a multi-center, two-arm, randomized, open label, phase II clinical trial of neoadjuvant and adjuvant immunotherapy with defactinib and pembrolizumab, following neoadjuvant standard of care (SOC) gemcitabine and nab-paclitaxel in subjects with high-risk resectable PDAC. The primary objectives aim to assess changes in CD8 T cell intratumoral infiltration utilizing multiplex IHC and the pathologic complete response rate with defactinib and pembrolizumab or pembrolizumab alone, following neoadjuvant chemotherapy. Secondary objectives include assessment of disease-free survival, overall survival, and safety. Translational exploratory objectives include evaluating stromal and immune signatures among treatment groups via multiplex IHC and RNA/DNA sequencing. 36 subjects will be randomly assigned to receive 400 mg defactinib PO BID and 200 mg pembrolizumab IV every 3 weeks (Arm A) or 200 mg pembrolizumab IV alone every 3 weeks (Arm B). After enrollment, subjects will undergo 2 cycles (̃2 months) of standard neoadjuvant therapy of gemcitabine and nab-paclitaxel, followed by 2 cycles (6 weeks) of investigational treatment (Arm A or B) before surgical resection. Following surgery, subjects will receive SOC adjuvant chemotherapy followed by investigational treatment (Arm A or B) for 8 cycles (̃24 weeks). Key inclusion criteria include: resectable PDAC, CA 19-9>200, no prior systemic treatment for PDAC, and ECOG PS ≤1. As of February 2022, 14 patients have been enrolled. Clinical trial information: NCT03727880.

RAD51B Harbors Germline Mutations Associated With Pancreatic Ductal Adenocarcinoma

PURPOSE

Genetic alterations in many components of the homologous recombination, DNA damage response, and repair (HR-DDR) pathway are involved in the hereditary cancer syndromes, including familial pancreatic cancer. HR-DDR genes beyond BRCA1, BRCA2, ATM, and PALB2 may also mutate and confer the HR-DDR deficiency in pancreatic ductal adenocarcinoma (PDAC).

METHODS

We conducted a study to examine the genetic alterations using a companion diagnostic 15-gene HR-DDR panel in PDACs. HR-DDR gene mutations were identified and characterized by whole-exome sequencing and whole-genome sequencing. Different HR-DDR gene mutations are associated with variable homologous recombination deficiency (HRD) scores.

RESULTS

Eight of 50 PDACs with at least one HR-DDR gene mutation were identified. One tumor with BRCA2 mutations is associated with a high HRD score. However, another tumor with a CHEK2 mutation is associated with a zero HRD score. Notably, four of eight PDACs in this study harbor a RAD51B gene mutation. All four RAD51B gene mutations were germline mutations. However, currently, RAD51B is not the gene panel for germline tests.

CONCLUSION

The finding in this study thus supports including RAD51B in the germline test of HR-DDR pathway genes.

Pathological treatment response has different prognostic implications for pancreatic cancer patients treated with neoadjuvant chemotherapy or chemoradiotherapy

BACKGROUND

Pathological treatment effect of resected pancreatic adenocarcinoma after neoadjuvant therapy has prognostic implications. The impact for patients who received chemotherapy alone or chemoradiotherapy is not well defined.

METHODS

Patients with localized pancreatic adenocarcinoma who had pancreatectomy after neoadjuvant therapy at 3 centers from 2011 to 2017 were retrospectively analyzed. The chemotherapy and chemoradiotherapy groups were evaluated separately.

RESULTS

Of 525 patients, 148 received neoadjuvant chemotherapy and 377 received chemoradiotherapy. The chemoradiotherapy group had a better treatment effect (score 0: 10%, score 1: 30%, score 2: 42%, and score 3: 18%) than the chemotherapy group (score 0: 2%, score 1: 8%, score 2: 35%, and score 3: 55%) (P < .001). Median overall survival was similar between the 2 groups (25.8 vs 26.4 months). Median overall survival for score 0/1, 2, or 3 was 72.2, 38.5, and 20.0 months in the chemotherapy group and 37.9, 24.5, and 19.0 months in the chemoradiotherapy group. Score 2 in the chemotherapy group was associated with better overall survival compared to score 3 (adjusted hazard ratio: 0.49, P = .005), whereas only combined score 0/1 reached significance over score 2 for the chemoradiotherapy group (hazard ratio: 0.63, P = .006).

CONCLUSION

The prognostic significance of pathological treatment effect for localized pancreatic adenocarcinoma differs for patients receiving neoadjuvant chemotherapy or neoadjuvant chemoradiotherapy.

Should non-invasive diffuse main-duct intraductal papillary mucinous neoplasms be treated with total pancreatectomy?

BACKGROUND

Main-duct (MD) intraductal papillary mucinous neoplasm (IPMN) is associated with malignancy risk. There is a lack of consensus on treatment (partial or total pancreatectomy) when the MD is diffusely involved. We sought to characterize the pancreatic remnant fate after partial pancreatectomy for non-invasive diffuse MD-IPMN.

METHODS

Consecutive patients with partial pancreatectomy for non-invasive MD-IPMN from 2004 to 2016 were analyzed. Diffuse MD-IPMN was defined by preoperative imaging as dilation of the MD in the head of the pancreas more than 5 mm and involving the whole gland.

RESULTS

Of 127 patients with resected non-invasive MD-IPMN, 47 (37%) had diffuse MD involvement. Eleven of 47(23%) patients developed imaging evidence of progression or new cystic disease in the pancreatic remnant. Patients with diffuse MD-IPMN were older (73yrs vs 67yrs, p = 0.009), more likely to receive a pancreaticoduodenectomy (96% vs 56%, p < 0.001) and have high-grade dysplasia (51% vs 31%, p = 0.025) than those with focal MD involvement. Diffuse MD involvement was not associated with shorter PFS following partial pancreatectomy (p = 0.613).

CONCLUSION

Partial pancreatectomy is an appropriate surgical approach for diffuse MD-IPMN, and is not associated with earlier progression after surgery as compared to partial pancreatectomy for focal dilation.

The Impact of the COVID-19 Pandemic on Multidisciplinary Clinics: A High-Volume Pancreatic Cancer Center Experience

The unprecedented impact of the Sars-CoV-2 pandemic (COVID-19) has strained the healthcare system worldwide. The impact is even more profound on diseases requiring timely complex multidisciplinary care such as pancreatic cancer. Multidisciplinary care teams have been affected significantly in multiple ways as healthcare teams collectively acclimate to significant space limitations and shortages of personnel and supplies. As a result, many patients are now receiving suboptimal remote imaging for diagnosis, staging, and surgical planning for pancreatic cancer. In addition, the lack of face-to-face interactions between the physician and patient and between multidisciplinary teams has challenged patient safety, research investigations, and house staff education. In this study, we discuss how the COVID-19 pandemic has transformed our high-volume pancreatic multidisciplinary clinic, the unique challenges faced, as well as the potential benefits that have arisen out of this situation. We also reflect on its implications for the future during and beyond the pandemic as we anticipate a hybrid model that includes a component of virtual multidisciplinary clinics as a means to provide accessible world-class healthcare for patients who require complex oncologic management.

Neoadjuvant Stereotactic Body Radiotherapy After Upfront Chemotherapy Improves Pathologic Outcomes Compared With Chemotherapy Alone for Patients With Borderline Resectable or Locally Advanced Pancreatic Adenocarcinoma Without Increasing Perioperative Toxicity

BACKGROUND

Patients with borderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) are at high risk of margin-positive resection. Neoadjuvant stereotactic body radiation therapy (SBRT) may help sterilize margins, but its additive benefit beyond neoadjuvant chemotherapy (nCT) is unclear. The authors report long-term outcomes for BRPC/LAPC patients explored after treatment with either nCT alone or nCT followed by five-fraction SBRT (nCT-SBRT).

METHODS

Patients with BRPC or LAPC from 2011 to 2016 who underwent resection after nCT alone or nCT-SBRT were retrospectively reviewed. Baseline characteristics were compared, and the propensity score with inverse probability weighting (IPW) was used to compare pathologic/survival outcomes.

RESULTS

Of 198 patients, 76 received nCT, and 122 received nCT-SBRT. The nCT-SBRT cohort had a higher proportion of LAPC (53% vs 22%; p < 0.001). The duration of nCT was longer for nCT-SBRT (4.6 vs 2.9 months; p = 0.03), but adjuvant chemotherapy was less frequently administered (53% vs 67.1%; p < 0.001). Adjuvant radiation was administered to 30% of the nCT patients. The nCT-SBRT regimen more frequently achieved negative margins (92% vs 70%; p < 0.001), negative nodes (59% vs 42%; p < 0.001), and pathologic complete response (7% vs 0%; p = 0.02). In the multivariate analysis, nCT-SBRT remained associated with R0 resection (p < 0.001). The nCT-SBRT cohort experienced no significant difference in median overall survival (OS) (22.1 vs 24.5 months), local progression-free survival (LPFS) (13.5 vs. 15.4 months), or distant metastasis-free survival (DMFS) (11.7 vs 16.3 months) after surgery. After SBRT, 1-year OS was 77.0% and 2-year OS was 50.4%. Perioperative Claven-Dindo grade 3 or greater morbidity did not differ significantly between the nCT and nCT-SBRT cohorts (p = 0.81).

CONCLUSIONS

Despite having more advanced disease, the nCT-SBRT cohort was still more likely to undergo an R0 resection and experienced similar survival outcomes compared with the nCT alone cohort.

Neoadjuvant and adjuvant antitumor vaccination alone or combination with PD1 blockade and CD137 agonism in patients with resectable pancreatic adenocarcinoma

558

Background: Utilizing a vaccine that induces and activates host effector T cells and co-administering it with immune modulating agents that enhance anti-tumor T cell activity is a potential strategy for overcoming pancreatic adenocarcinoma’s (PDA) resistance to immunotherapy. Our prior clinical trial demonstrated a GM-CSF-secreting, allogeneic tumor cell vaccine (GVAX) increases infiltrating CD8+ T cells in PDA. Follow up preclinical work demonstrated therapeutic synergy between GVAX and PD-1inhibition (PD1) with efficacy further enhanced by CD137 agonism (CD137). Methods: This was a 3-arm trial of neoadjuvant & adjuvant GVAX-based therapy in resectable (r) PDA patients (pts). Adults with clinically resectable, untreated PDA were enrolled in 1 of 3 study treatments: Arm A (GVAX alone), Arm B (GVAX + PD1 [Nivolumab]), or arm C (GVAX + PD1 + CD137 [Urelumab]). Treatment was given as follows: Day 1 - Cyclophosphamide 200mg/m2 IV (All Arms), Nivolumab 480mg IV (Arms B, C), Urelumab 8mg IV (Arm C); Day 2 – GVAX ID (All Arms). Pts were treated at 3 timepoints: 1) once 2 weeks prior to surgery; 2) once post-surgical recovery prior to standard of care adjuvant chemotherapy (SOC); 3) every month (up to 4 mo) following completion of SOC (if disease-free). SOC regimes included (m)FOLFIRINOX, Gem +/- Cap/NAB-Paclitaxel. The study was powered for a primary biologic endpoint: treatment-related change in intratumoral CD8+CD137+ T cells. Clinical endpoints included disease-free survival (DFS: time from surgery to recurrence), overall survival (OS: time from surgery to death), and safety. Results: 38 pts (N = 15 [Arm A], N = 13 [Arm B], N = 10 [Arm C]) were eligible for efficacy analysis (had R0/R1 resection) and 45 pts (N = 17 [A], N = 17 [B], N = 11 [C]) were eligible for safety analysis (had ≥1 dose of study treatment). Demographics, surgical pathology features, and SOC durations were similar in all Arms. At median follow up of 23 mo [A], 26 mo [B], and 22 mo [C], median DFS (95% CI) was 14.82 mo (6.0, NA), 16.23 mo (7.49, NA) and not reached (16.33, NA) for Arms A, B, C, respectively. There was no DFS benefit to adding PD1 compared to GVAX alone (HR 0.98 [95% CI 0.42, 2.27], p = 0.96). Combination CD137 + PD1 + GVAX was associated with marginally significant improved DFS compared to GVAX alone (HR 0.38 [95%CI 0.12, 1.19], p = 0.097) and GVAX + PD1 (HR 0.38 [95%CI 0.12, 1.21], p = 0.103). Median OS (95% CI) was 25.0 mo (18.8, NA), 26.4 mo (20.3, NA), and not yet reached for Arms A, B, C, respectively. There were no serious adverse events. In Arm C, 1 pt had grade 3 rash that delayed treatment and there was 1 instance of grade 2 AST/ALT elevation. The biologic endpoint will be reported at the meeting. Conclusions: Despite a small sample size, combining GVAX with dual immune-targeting of PD-1 blockade and CD137 agonism was safe and may enhance DFS in rPDA pts treated in the perioperative and post-adjuvant settings. Clinical trial information: NCT02451982.

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.

Reliable Detection of Somatic Mutations for Pancreatic Cancer in Endoscopic Ultrasonography-Guided Fine Needle Aspirates with Next-Generation Sequencing: Implications from a Prospective Cohort Study

BACKGROUND OR PURPOSE

Pancreatic ductal adenocarcinoma (PDAC) is commonly diagnosed by endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). However, the diagnostic adequacy of EUS-FNA is often limited by low cellularity leading to inconclusive results. We aimed to investigate the feasibility and added utility of targeted next-generation sequencing (NGS) on PDAC EUS-FNAs.

METHODS

EUS-FNAs were prospectively performed on 59 patients with suspected PDAC (2014-2017) at a high-volume center. FNAs were analyzed for the presence of somatic mutations using NGS to supplement cytopathologic evaluations and were compared to surgical specimens and circulating tumor DNA (ctDNA).

RESULTS

Fifty-nine patients with suspected PDAC were evaluated, and 52 were diagnosed with PDAC on EUS-FNA. Four of the remaining seven patients had inconclusive EUS-FNAs and were ultimately diagnosed with PDAC after surgical resection. Of these 56 cases of PDAC, 48 (85.7%) and 18 (32.1%) harbored a KRAS and/or TP53 mutation on FNA NGS, respectively. Particularly, in the four inconclusive FNA PDAC diagnoses (false negatives), half harbored KRAS mutations on FNA. No KRAS/TP53 mutation was found in remaining three non-PDAC cases. All EUS-FNA detected KRAS mutations were detected in 16 patients that underwent primary tumor NGS (100% concordance), while 75% KRAS concordance was found between FNA and ctDNA NGS.

CONCLUSION

Targeted NGS can reliably detect KRAS mutations from EUS-FNA samples and exhibits high KRAS mutational concordance with primary tumor and ctDNA. This suggests targeted NGS of EUS-FNA samples may enable preoperative ctDNA prognostication using digital droplet PCR and supplement diagnoses in patients with inconclusive EUS-FNA.

Implantation of a neoantigen-targeted hydrogel vaccine prevents recurrence of pancreatic adenocarcinoma after incomplete resection

Tumor involvement of major vascular structures limits surgical options in pancreatic adenocarcinoma (PDAC), which in turn limits opportunities for cure. Despite advances in locoregional approaches, there is currently no role for incomplete resection. This study evaluated a gelatinized neoantigen-targeted vaccine applied to a grossly positive resection margin in preventing local recurrence. Incomplete surgical resection was performed in mice bearing syngeneic flank Panc02 tumors, leaving a 1 mm rim adherent to the muscle bed. A previously validated vaccine consisting of neoantigen peptides, a stimulator of interferon genes (STING) agonist and AddaVax^TM (termed PancVax) was embedded in a hyaluronic acid hydrogel and applied to the tumor bed. Tumor remnants, regional lymph nodes, and spleens were analyzed using histology, flow cytometry, gene expression profiling, and ELISPOT assays. The immune microenvironment at the tumor margin after surgery alone was characterized by a transient influx of myeloid-derived suppressor cells (MDSCs), prolonged neutrophil influx, and near complete loss of cytotoxic T cells. Application of PancVax gel was associated with enhanced T cell activation in the draining lymph node and expansion of neoantigen-specific T cells in the spleen. Mice implanted with PancVax gel demonstrated no evidence of residual tumor at two weeks postoperatively and healed incisions at two months postoperatively without local recurrence. In summary, application of PancVax gel at a grossly positive tumor margin led to systemic expansion of neoantigen-specific T cells and effectively prevented local recurrence. These findings support further work into locoregional adjuncts to immune modulation in PDAC.

Abstract PO-111: A human single-cell RNA sequencing atlas of pancreatic ductal adenocarcinoma enables harmonized cell type calling and comprehensive analyses of potential intercellular signaling

Purpose: Pancreatic ductal adenocarcinoma (PDAC) is characterized by a dismal prognosis, low ductal cancer cellularity and a dominant tumor microenvironment (TME) in response to malignant degeneration. Modern single-cell RNA sequencing (scRNA-seq) platforms fundamentally improved the opportunities to analyze PDAC biology through isolation of diverse cell types including ductal, mesenchymal, myeloid and lymphoid populations. Published scRNA-seq data of PDAC patients provide innovative and astounding insights, but are limited by cohort size and intrinsically vulnerable to internal biases. Herein, we present a human single-cell PDAC atlas which links the previous sequencing efforts aiming for increasing depth and robustness with the combined analysis of transcriptomes. Methods: We selected scRNA-seq data of all patients with PDAC from six publicly available datasets (published between 2019-2020). Altogether, 61 different human samples with 142,807 cells were integrated into one dataset leveraging 15,219 genes, which were conclusively identical between all datasets based on the utilized nomenclature in the provided raw data. In addition, we extracted 16 samples with 31,587 cells from control pancreas specimens which were included in three out of the six datasets. The analyses were performed using the R statistics and Python environments utilizing established software including Monocle3 and Seurat. Results: After computational preprocessing of the integrated dataset, cell types were identified based on differentially expressed and canonical markers. The generated PDAC atlas consists of 26% ductal cancer, 2% ductal normal, 12% mesenchymal (stellate cells and cancer-associated fibroblasts), 18% myeloid, 19% lymphoid and 23% other cells (including acinar and endocrine cells). Copy number variation analyses confirmed the discrimination between cancer and normal ductal cells. Certain subpopulations within cell types were mapped based on the expression of supervised gene sets. Within the ductal cancer cell population, the Classical and Basal-like Moffitt signatures coexisted in the majority of patients with distinct ratios and predominance, which were associated with differences in the TME composition. Furthermore, the presence of myofibroblasts and inflammatory fibroblasts could be quantified at the patient-level. The reconstruction of intercellular signaling between ductal cancer cells and several TME components revealed potential ligands, receptors and transcription factors that may functionally define routes and polarity of cross-talk in PDAC. Conclusion: This human scRNA-seq atlas is the largest available dataset of patients with PDAC while harmonizing previously published data. It is engineered to analyze current knowledge gaps with increased rigor and, most importantly, overcomes obstacles related to bulk transcriptome sequencing data. Molecular characteristics of the ductal cancer cells and TME components inferred from the presented framework are promising to identify disease- and patient-specific signaling, key regulators, and therapeutic targets.

Citation Format: Benedict Kinny-Köster, Melissa R. Lyman, Dimitrios N. Sidiropoulos, Melanie Loth, Alexandra B. Puscek, Laura D. Wood, Jin He, Jun Yu, Richard A. Burkhart, Elizabeth M. Jaffee, Jacquelyn W. Zimmerman, Elana J. Fertig. A human single-cell RNA sequencing atlas of pancreatic ductal adenocarcinoma enables harmonized cell type calling and comprehensive analyses of potential intercellular signaling [abstract]. In: Proceedings of the AACR Virtual Special Conference on Pancreatic Cancer; 2021 Sep 29-30. Philadelphia (PA): AACR; Cancer Res 2021;81(22 Suppl):Abstract nr PO-111.

Postoperative biliary anastomotic strictures after pancreaticoduodenectomy

BACKGROUND

Biliary anastomotic stricture (BAS) is an uncommon complication of pancreaticoduodenectomy (PD). As PDs are performed more frequently, BAS may become a more common pathologic entity requiring clinical engagement. The aim of this study was to report the incidence of BAS in the modern era of pancreatic surgery and identify risk factors associated with it.

METHODS

Patients undergoing PD at the Johns Hopkins Hospital between 2007 and 2016 were identified using an institutional registry and clinicopathological features were analyzed to identify risk factors associated with BAS.

RESULTS

Of 2125 patients identified, 103 (4.9%) developed BAS. Factors independently associated with BAS included laparoscopic approach (HR:2.83,95%CI:1.35-5.92, p = 0.006), postoperative pancreatic fistula (HR:2.45,95%CI:1.56-4.16,p < 0.001), postoperative bile leak (BL) (HR:5.26,95%CI:2.45-11.28,p < 0.001), and administration of adjuvant radiation therapy (HR:6.01,95%CI:3.19-11.34,p < 0.001). Malignant pathology was associated with lower rates of BAS (HR:0.52,95%CI:0.30-0.92, p = 0.025). BL was associated with higher rates of early-BAS (HR:16.49,95%CI:3.28-82.94, p = 0.001) while use of Vicryl suture for biliary enteric anastomosis was associated with lower rates of early-BAS (HR:0.20,95%CI:0.05-0.93, p = 0.041).

CONCLUSION

Approximately 5% of patients undergoing PD experience BAS. Multiple factors are associated with the development and timing of BAS.

Impact of Postoperative Glycemic Control on Postoperative Morbidity in Patients Undergoing Open Pancreaticoduodenectomy

OBJECTIVE

To evaluate the impact of postoperative glycemic control on postoperative morbidity in patients undergoing a pancreaticoduodenectomy.

METHODS

A retrospective study was performed on patients at The Johns Hopkins Hospital between April 2015 and April 2016. Data were collected on postoperative insulin regimens, blood glucose, rates of hyperglycemia and hypoglycemia, and postoperative complications and were evaluated.

RESULTS

Out of 244 patients, 114 (46.7%) experienced at least 1 hyperglycemic (>180 mg/dL) episode and 16 (6.6%) experienced at least 1 hypoglycemic episode (<70 mg/dL) during the first postoperative 24 hours. Early postoperative hyperglycemia (>180 mg/dL) was associated with a significantly higher rate of surgical site infections (15.7% vs 7%; P = 0.031). Late postoperative hyperglycemia (>180 mg/dL) was associated with a significantly higher rate of fistulas (4.3% vs 14.6%; P = 0.021).

CONCLUSIONS

Early hyperglycemia (>180 mg/dL) is associated with a higher risk of surgical site infections while late hyperglycemia is associated with a higher risk of fistulas. Intensive glucose control (<150 mg/dL) was not demonstrated to decrease the risk of postoperative complications. Similar to other critically ill populations, targeting a glucose goal of <180 mg/dL may be an appropriate target to reduce morbidity without increasing the risk of hypoglycemia.

Abstract 2372: Mechanisms of microRNA-21 dysregulation in pancreatic ductal adenocarcinoma (PDAC)

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a devastating malignancy with tumorigenesis largely driven by a nearly ubiquitous activating KRAS (mKRAS) mutation. Thus far efforts to target mKRAS have been largely unsuccessful due to compensatory mechanisms and associated toxicity. MicroRNAs (miRNAs) are short non-coding RNAs that represent a novel avenue to target KRAS effector function through post-transcriptional regulation. We recently described dysregulation of miRNA-21 (miR-21) in transgenic KrasG12D/+;Trp53R172H/+;Pdx-1-Cre (KPC) mice as a cell- and compartment-specific regulator of tumor epithelial cells. Here we report on the use of human models to elucidate the underlying mechanisms responsible for cellular phenotypes defined by KPC modeling.

Experimental Procedures: The Cancer Genome Atlas (TCGA) was leveraged to computationally identify putative targets of miR-21 and additional pathways of interest for transcriptional and functional experiments. Concurrently, de-novo patient-derived organoid (PDO) models were generated from core biopsies and surgical resection specimens and expanded in Matrigel for current experiments. miR-21 expression in five PDO cell lines is profiled using qPCR. Stable knock-down of miR-21 is explored using lentiviral constructs in PDOs and cancer associated fibroblasts (CAFs) for use in a co-culture models to examine the mechanisms of action of miR-21 and investigating messenger RNA targets (mRNA) of miR-21. We have simultaneously used TCGA to examine targets of miR-21 and identify pathways of interest for further transcriptional and functional experiments.

Results: Analysis of TCGA PDAC cohort examined 48 putative targets of miR-21. Decreases in the target mRNA levels of these 48 targets were heterogenous. Prominently, an inverse relationship was identified between miR-21 expression and the expression of one of its target mRNAs: programmed cell death protein 4 (PDCD4). Gene set enrichment analysis is underway to identify additional biologic targets of interest. Evaluation of miR-21 expression in PDO and matched CAF cell lines demonstrated robust and repeatable miR-21 identification as well as stability of knocked down miR-21 expression following transduction with a lentiviral miR-21 inhibitor construct.

Conclusions: We previously demonstrated that miR-21 appears to be an early and reliable molecular marker of pancreatic neoplasia. The lack of global inverse relationship between miR-21 and target messenger RNA expression suggests more complexity to this regulation or bias from TCGA cohort, as the majority of patients in this cohort have early stage disease. These findings warrant additional mechanistic evaluation of specific targets such as PDCD4, which may have significant biologic importance and insight into our previously described phenotype. PDOs are powerful models for these mechanistic studies.

Citation Format: Jacquelyn W. Zimmerman, Richard A. Burkhart, Elana J. Fertig, Elizabeth M. Jaffee. Mechanisms of microRNA-21 dysregulation in pancreatic ductal adenocarcinoma (PDAC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2372.

A phase 2 study of cyclophosphamide (CY), GVAX, pembrolizumab (Pembro), and stereotactic body radiation (SBRT) in patients (pts) with locally advanced pancreas cancer (LAPC)

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Background: Management of locally advanced pancreas cancer (LAPC) standardly involves chemotherapy with consolidative radiation and surgery in selected pts. Checkpoint inhibitors have shown limited benefit alone in pancreas cancer but may be primed by radiation and GM-CSF secreting allogeneic pancreatic cancer vaccine (GVAX). We present data from a phase 2 study for LAPC pts who have not developed metastases after standard of care chemotherapy treated with combination cyclophosphamide (CY), GVAX, pembrolizumab (pembro), and stereotactic body radiation therapy (SBRT). Methods: This is a single-arm, single institution, open-label study for pts with LAPC at diagnosis (as per NCCN guidelines, arterial involvement > 180°, or unreconstructible SMV/PV) who remained without metastatic disease after 4-8 28-day cycles FOLFIRINOX or gemcitabine/abraxane based therapy. Pts received CY (200mg/m2 IV) and pembro (200mg IV) on day 1, followed by GVAX (6 intradermal inj) on day 2 q3 wk x 2 cycles, with cycle 2 initiating concurrently with 5 days SBRT. Pts were restaged 4-6 weeks after SBRT, and if non-metastatic, pts underwent surgical resection, irreversible electroporation (IRE), or biopsy (if not undergoing surgical resection). Pts received two cycles of chemotherapy, and if metastasis free, received q3 wk CY/pembro/GVAX x 6 cycles with restaging scans q3 mos. In 5/2017, the protocol was addended to include an extended phase with q3 wk pembro x 9 cycles and q6 mo CY/GVAX x 4. Primary endpoint was distant metastasis free survival (DMFS) defined as C1D1 to distant metastases or death. Results: From Jul 2016-Jan 2021, 58 pts with LAPC were enrolled at the Johns Hopkins Hospital, 54 completed 2 cycles CY/pembro/GVAX and SBRT and were evaluable for response (2 dropouts due to thrombocytopenia, 2 due to irAE (DKA and hepatitis)), median followup was 15.8 mos. Demographics: median age 66 (range 42-84), 53% male, 84% White, 12% African American. At first restaging (N = 54), 8 (15%) had metastatic disease, 9 (17%) were unresectable, 37 (69%) were eligible for surgical resection. 35 pts proceeded to the OR (1 died of cholangitis prior to surgery and 1 declined surgery), 24 had tumors resected (44% of evaluable pts, 10 (42%) had grade 1 (marked) pathologic response), 1 IRE, 2 were unresectable, 8 were metastatic. Common related AEs were vaccine site reactions; grade 3 irAE included 1 case each of dermatitis, colitis, DKA, nephritis, and pneumonitis. DMFS was 9.7 mos [95% CI 6.3-19.3 mos]. Conclusions: We present data from a ph II study of 54 pts w LAPC treated w CY/GVAX/pembro and SBRT. Primary endpoint of DMFS > 13.6 mos not reached, however 44% of pts underwent surgical resection of whom 42% had grade 1 path response rate. Additional correlative studies are underway. Clinical trial information: NCT02648282.

Development, Practice Patterns, and Early Clinical Outcomes of a Multidisciplinary Liver Cancer Clinic

Multidisciplinary care has been associated with improved survival in patients with primary liver cancers. We report the practice patterns and real world clinical outcomes for patients presenting to the Johns Hopkins Hospital (JHH) multidisciplinary liver clinic (MDLC). We analyzed hepatocellular carcinoma (HCC, n = 100) and biliary tract cancer (BTC, n = 76) patients evaluated at the JHH MDLC in 2019. We describe the conduct of the clinic, consensus decisions for patient management based on stage categories, and describe treatment approaches and outcomes based on these categories. We describe subclassification of BCLC stage C into 2 parts, and subclassification of cholangiocarcinoma into 4 stages. A treatment consensus was finalized on the day of MDLC for the majority of patients (89% in HCC, 87% in BTC), with high adherence to MDLC recommendations (91% in HCC, 100% in BTC). Among patients presenting for a second opinion regarding management, 28% of HCC and 31% of BTC patients were given new therapeutic recommendations. For HCC patients, at a median follow up of 11.7 months (0.7-19.4 months), median OS was not reached in BCLC A and B patients. In BTC patients, at a median follow up of 14.2 months (0.9-21.1 months) the median OS was not reached in patients with resectable or borderline resectable disease, and was 11.9 months in patients with unresectable or metastatic disease. Coordinated expert multidisciplinary care is feasible for primary liver cancers with high adherence to recommendations and a change in treatment for a sizeable minority of patients.

Guidelines on management of pancreatic cysts detected in high-risk individuals: An evaluation of the 2017 Fukuoka guidelines and the 2020 International Cancer of the Pancreas Screening (CAPS) consortium statements

BACKGROUND

Objectives: Pancreatic cysts are frequently detected in high-risk individuals (HRI) undergoing surveillance for pancreatic cancer. The International Cancer of the Pancreas Screening (CAPS) Consortium developed consensus recommendations for surgical resection of pancreatic cysts in HRI that are similar to the Fukuoka guidelines used for the management of sporadic cysts. We compared the performance characteristics of CAPS criteria for pancreatic cyst management in HRI with the Fukuoka guidelines originally designed for the management of cysts in non-HRI.

METHODS

Using prospectively collected data from CAPS studies, we determined for each patient with resected screen-detected cyst(s) whether Fukuoka guidelines or CAPS consensus statements would have recommended surgery. We compared sensitivity, specificity, PPV, NPV, and Receiver Operator Characteristics (ROC) curves of these guidelines at predicting the presence of high-grade dysplasia or invasive cancer in pancreatic cysts.

RESULTS

356/732 HRI had ≥ one pancreatic cyst detected; 24 had surgery for concerning cystic lesions. The sensitivity, specificity, PPV, and NPV for the Fukuoka criteria were 40%, 85%, 40%, and 85%, while those of the CAPS criteria were 60%, 85%, 50%, 89%, respectively. ROC curve analyses showed no significant difference between the Fukuoka and CAPS criteria.

CONCLUSIONS

In HRI, the CAPS and Fukuoka criteria are moderately specific, but not sufficiently sensitive for detecting advanced neoplasia in cystic lesions. New approaches are needed to guide the surgical management of cystic lesions in HRI.

Defining a minimum number of examined lymph nodes improves the prognostic value of lymphadenectomy in pancreas ductal adenocarcinoma

BACKGROUND

Lymph node (LN) metastasis is associated with decreased survival following resection for pancreatic ductal adenocarcinoma (PDAC). In N0 disease, increasing total evaluated LN (ELN) correlates with improved outcomes suggesting patients may be understaged when LNs are undersampled. We aim to assess the optimal number of examined lymph nodes (ELN) following pancreatectomy.

METHODS

Data from 1837 patients undergoing surgery were prospectively collected. The binomial probability law was utilized to analyze the minimum number of examined LNs (minELN) and accurately characterize each histopathologic stage. LN ratio (LNR) was compared to American Joint Committee on Cancer (AJCC) guidelines.

RESULTS

As ELN total increased, the likelihood of finding node positive disease increased. An evaluation based upon the binomial probability law suggested an optimal minELN of 12 for accurate AJCC N staging. As the number of ELNs increased, the discriminatory capacity of alternative strategies to characterize LN disease exceeded that offered by AJCC N stage.

CONCLUSION

This is the first study dedicated to optimizing histopathologic staging in PDAC using models of minELN informed by the binomial probability law. This study highlights two separate cutoffs for ELNs depending upon prognostic goal and validates that 12 LNs are adequate to determine AJCC N stage for the majority of patients.

Autoimmune Pancreatitis: A Critical Analysis of the Surgical Experience in an Era of Modern Diagnostics

OBJECTIVE

The aim of this study was to critically analyze the surgical experience of managing autoimmune pancreatitis (AIP) in an era of modern diagnostics and compare these patients with those who were managed conservatively.

METHODS

Two prospectively maintained databases were used to retrospectively identify patients with AIP who were either managed conservatively or underwent pancreatectomy.

RESULTS

Eighty-eight patients were included in the study, of which 56 (63.6%) underwent resection and 32 (36.4%) were managed conservatively. Patients who underwent resection were more likely to present with jaundice (64.3% vs 18.1%, P < 0.001) and weight loss (53.6% vs 15.6%, P = 0.005). The cohort who underwent resection had a significantly higher median carbohydrate antigen 19-9 (40.0 vs 18.6 U/mL, P = 0.034) and was less likely to have elevated immunoglobulin G4 (26.1% vs 50.0%, P < 0.001). The most frequent initial diagnosis in the cohort who underwent resection was ductal adenocarcinoma (82.1%). Nine patients (28.1%) in the conservatively managed cohort experienced AIP relapse compared with 6 patients (10.7%) in the cohort who underwent resection.

CONCLUSIONS

The most frequent reason for surgical resection of AIP is concern for malignancy. Carbohydrate antigen 19-9 elevations were more common than immunoglobulin G4 in our cohort, suggesting that this laboratory profile is suboptimal for this population.

Role of Lymph Node Resection and Histopathological Evaluation in Accurate Staging of Nonfunctional Pancreatic Neuroendocrine Tumors: How Many Are Enough?

BACKGROUND

Nodal involvement has been identified as one of the strongest prognostic factors in patients with nonfunctional pancreatic neuroendocrine tumors (NF-PanNETs). Sufficient lymphadenectomy and evaluation is vital for accurate staging. The purpose of this study was to identify the optimal number of examined lymph nodes (ELN) required for accurate staging.

METHODS

The SEER database was used to identify patients with resected NF-PanNETs between 2004 and 2014. The distributions of positive lymph nodes (PLN) ratio and total lymph nodes were used to develop a mathematical model. The sensitivity of detecting nodal disease at each cutoff of ELN was estimated and used to identify the optimal cutoff for ELN.

RESULTS

A total of 1098 patients were included in the study of which 391 patients (35.6%) had nodal disease. The median ELN was 12 (interquartile range [IQR]: 7-19.5), and the median PLN was 2 (IQR: 1-4) for patients with nodal disease. With an increase in ELN, the sensitivity of detecting nodal disease increased from 12.0% (ELN: 1) to 92.2% (ELN: 20), plateauing at 20 ELN (< 1% increase in sensitivity with an additional ELN). This sensitivity increase pattern was similar in subgroup analyses with different T stages.

CONCLUSIONS

The sensitivity of detecting nodal disease in patients with NF-PanNETs increases with an increase in the number of ELN. Cutoffs for adequate nodal assessment were defined for all T stages. Utilization of these cutoffs in clinical settings will help with patient prognostication and management.

Challenges of the current precision medicine approach for pancreatic cancer: A single institution experience between 2013 and 2017

Recent research on genomic profiling of pancreatic ductal adenocarcinoma (PDAC) has identified many potentially actionable alterations. However, the feasibility of using genomic profiling to guide routine clinical decision making for PDAC patients remains unclear. We retrospectively reviewed PDAC patients between October 2013 and December 2017, who underwent treatment at the Johns Hopkins Hospital and had clinical tumor next-generation sequencing (NGS) through commercial resources. Ninety-two patients with 93 tumors tested were included. Forty-eight (52%) patients had potentially curative surgeries. The median time from the tissue available to the NGS testing ordered was 229 days (interquartile range 62-415). A total of three (3%) patients had matched targeted therapies based on genomic profiling results. Genomic profiling guided personalized treatment for PDAC patients is feasible, but the percentage of patients who receive targeted therapy is low. The main challenges are ordering NGS testing early in the clinical course of the disease and the limited evidence of using a targeted approach in these patients. A real-time department level genomic testing ordering system in combination with an evidence-based flagging system for potentially actionable alterations could help address these shortcomings.

Long-term outcomes with neoadjuvant chemotherapy with or without stereotactic body radiation therapy in patients with borderline resectable and locally advanced pancreatic adenocarcinoma

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Background: Patients (pts) withborderline resectable pancreatic cancer (BRPC) or locally advanced pancreatic cancer (LAPC) are at high risk of margin positive resection with upfront surgery. Pre-operative stereotactic body radiation therapy (SBRT) may help sterilize vascular margins, but its additive benefit beyond multi-agent chemotherapy (CTX) is unclear. We report on long-term outcomes from a high-volume institution of BRPC/LAPC pts who were reviewed by a multidisciplinary team and explored after either multi-agent CTX alone or multi-agent CTX followed by SBRT. Methods: Consecutive BRPC/LAPC pts diagnosed 2011-2016 who underwent resection following CTX alone or CTX followed by 5-fraction SBRT (CTX-SBRT) were retrospectively reviewed. Baseline demographic, clinical, and treatment factors were compared between cohorts, and survival analysis was conducted to compare pathologic and survival outcomes. Results: Of 199 pts, 77 received CTX alone and 122 received CTX-SBRT. There was no significant difference between cohorts in age, gender, performance status, tumor location, CA19-9 at diagnosis, or post-CTX CA19-9 values (all p > 0.05). The CTX-SBRT cohort had a higher proportion of pts with LAPC as compared to the CTX cohort (53% vs 22%, p< 0.001). Modified FOLFIRINOX (mFFX) was administered to 55% of pts, while 70% of pts received either mFFX or gemcitabine/abraxane, with no difference between cohorts. Duration of CTX was longer in the CTX-SBRT cohort as compared to the CTX cohort (median 4.6 vs. 2.9 mos, p= 0.03), but adjuvant CTX was not given as often in the CTX-SBRT arm (60.4% vs. 86.4%, p= < 0.001). Notably, 30% of the CTX cohort also received adjuvant chemoradiation. Pathologic response was significantly improved in the CTX-SBRT cohort vs the CTX cohort, specifically negative margins (92% vs 70%, p< 0.001), node negative (59% vs. 42%, p< 0.001), and pathologic complete response (7% vs. 0%, p= 0.02). On multivariable analysis, after controlling for prognostic factors, CTX-SBRT remained significantly associated with margin negative resection ( p< 0.001). Despite having more advanced stage and less adjuvant therapy administration in the CTX-SBRT cohort, there was no significant difference in overall survival after surgery (median OS: 24.6 vs. 22.2 mo, p= 0.79), local progression free survival (14.0 vs. 13.6 mo, p= 0.33), or distant metastasis free survival (16.4 vs. 11.8 mo, p= 0.33). Conclusions: Despite more advanced disease at presentation, BRPC/LAPC pts treated with CTX-SBRT were more likely to undergo margin negative resection and experienced similar survival outcomes, as compared to CTX alone. More data are needed to refine which patients benefit from neoadjuvant SBRT and how RT administration can be optimized to impact survival outcomes.

Long-term outcomes of a prospective single institution study with multiagent chemotherapy and stereotactic body radiation therapy in locally advanced or recurrent pancreatic adenocarcinoma

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Background: We previously reported a multi-center study in which gemcitabine and stereotactic body radiation therapy (SBRT) were shown to be safe with outcomes comparable to chemoradiation in locally advanced pancreatic cancer (LAPC). This prospective clinical trial was developed to evaluate the efficacy of adding SBRT to multi-agent chemotherapy in LAPC. Herein, we report on the long-term survival outcomes. Methods: From 2012 to 2015, 48 patients (pts) were prospectively enrolled after multidisciplinary evaluation at a single high-volume pancreatic center. Pts received multi-agent chemotherapy (CTX) with modified mFOLFIRINOX (mFFX) or gemcitabine/abraxane followed by 5 fractions of SBRT (median 33 Gy; range, 25-33 Gy). At the time of fiducial placement, biopsies were obtained and DNA extracted for targeted sequencing using MSK-IMPACT. Kaplan-Meier curves were generated to compare survival outcomes by sub-group. Multivariate analysis (MVA) was performed to identify factors prognostic for survival. Results: 44 pts (91.7%) had LAPC disease and 4 (8.3%) had locally recurrent disease. The median follow-up interval was 21.5 months (mo) from diagnosis. CTX consisted of mFFX in 25 pts (52.1%) with 24 pts (50.0%) receiving therapy for a duration ≥4 mo. Of 44 pts with LAPC, 15 (34.1%) were surgically explored, and 11 (73.3%) achieved a margin-negative resection. From diagnosis and after completion of SBRT, respectively, the median overall survival (OS) was 21.6 (95% CI 16-29.7 mo) and 14.6 mo (95% CI: 11.6-23.0 mo); median progression free survival (PFS) was 13.2 (95% CI 11.9-18.1mo) and 6.4 mo (95% CI: 5-12.7 mo); median local PFS (LPFS) was 23.9 (95% CI 18.9-56.9 mo) and 15.8 mo (95% CI: 12.9-27.6 mo); and median distant metastasis free survival (DMFS) was 18.4 (95% CI 12.6-29.3 mo) and 8.5 mo (95% CI: 6.3-17.2 mo). Resected pts experienced better DMFS at 1-year (78% vs. 34%, p= 0.004) with an improved trend for 1-year OS (73% vs. 52%, p= 0.331). If CTX duration was ≥4 mo, 1-year OS (75% vs. 42%, p= 0.018), PFS (50% vs. 21%, p= 0.022), and DMFS (72% vs. 29%, p= 0.031) were significantly improved. In 44 LAPC pts, MVA confirmed ≥4 mo duration of CTX was associated with OS, PFS, and DMFS. Surgical resection was associated with improved DMFS, and CA19-9 level prior to SBRT was associated with PFS and LPFS. The most common mutations detected from biopsy specimens were KRAS (64.3%) , TP53 (50%), and SMAD4 (16.7%). Conclusions: In a prospective trial of pts with LAPC receiving multiagent CTX and SBRT, clinical outcomes were improved with longer durations of CT ( > 4 mo). A high proportion of LAPC pts underwent margin negative resection with favorable outcomes. Future studies should focus on which pts are most likely to benefit from SBRT and surgery following multiagent CTX. In pts who cannot undergo resection, escalated doses of SBRT may be indicated. Clinical trial information: NCT01781728.

Feasibility and efficacy of neoadjuvant cabozantinib and nivolumab in patients with borderline resectable or locally advanced hepatocellular carcinoma (HCC)

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Background: Only 10-15% of newly diagnosed HCC patients are candidates for a potentially curative resection, and most patients who receive resection eventually recur. Historical systemic therapies including sorafenib, as well as locoregional therapies, have not demonstrated benefit in the perioperative setting. Novel combinations of targeted therapies and immunotherapies demonstrate higher response rates than sorafenib in HCC. Here, we report the feasibility and efficacy of neoadjuvant combination therapy with cabozantinib plus nivolumab, followed by surgical resection, in patients with borderline resectable or locally advanced HCC. Methods: We conducted an open-label, single-arm, phase I study in patients with HCC with borderline resectable or locally advanced HCC (including multinodular disease, portal vein involvement, or other high-risk features). Patients received 8 weeks of therapy with cabozantinib 40 mg oral daily plus nivolumab 240 mg IV every two weeks, followed by restaging and possible surgical resection. The primary endpoint was feasibility, defined by the percentage of patients experiencing a treatment-related adverse event that precluded continuing on to surgery within 60 days of the planned date for surgical evaluation. Results: We enrolled 15 patients of whom 14 patients completed neoadjuvant therapy and underwent surgical evaluation. Adverse events were consistent with prior experience with these agents, and the trial met its primary endpoint, with no patients experiencing a treatment-related adverse event that precluded timely surgical assessment. Of patients completing neoadjuvant therapy, 1 patient declined surgery, 1 tumor could not be resected, and 12 patients underwent successful R0 surgical resection. 5/12 (41.7%) resected patients had a major or complete pathologic response. At a median follow up of one year, 4/5 pathologic responders are without recurrence. We performed an in-depth profiling of the surgical resection biospecimens and identified an enrichment of IFNγ+ effector memory CD4+ and granzyme B+ effector CD8+ T cells as well as tertiary lymphoid aggregates in the pathologic responders. We further analyzed the spatial relationships of cell types in responders and non-responders, which identified distinct spatial arrangement of B cells in responders, and proximity of arginase-1 expressing myeloid cells to T cells in nonresponders. Conclusions: This study is, to our knowledge, the first use of a targeted therapy in combination with an immune checkpoint inhibitor in the neoadjuvant setting in HCC, and the first use of modern systemic therapies to expand surgical resection criteria. Neoadjuvant cabozantinib and nivolumab is feasible, and may result in pathologic responses and long-term disease-free survival in a group of patients who may be outside traditional resection criteria. Clinical trial information: NCT03299946.

Clinical and molecular features of adenosquamous pancreatic cancer (ASQ): A distinct histological subtype

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Background: Adenosquamous pancreatic cancers (ASQ) constitute 1-5% of all pancreatic cancers. The clinical and molecular understanding of this aggressive variant, along with potential differential response to systemic therapies, is an understudied yet important topic. Methods: After obtaining Institutional Review Board approvals, the Johns Hopkins cancer registry and electronic medical record was interrogated for histopathological and clinical characteristics of ASQ. Archived pathological slides were re-examined to quantify the squamous component, response to neoadjuvant therapy and immune infiltrate. Results: Of 8,908 patients from 2003 to 2018, a total of 155 had histology consistent with ASQ. 52% presented with resectable disease, 12% with borderline resectable, 12% with locally advanced, 17% with metastatic, and 8% of cases had an unknown presentation status. Primary FNA diagnosis was available for 103 patients and 57% (n = 59) reported squamous findings on FNA. 53 patients received radiation therapy (19 neoadjuvant, 22 adjuvant, 15 palliative). Systemic therapy was received by 104 patients (32 neoadjuvant, 52 adjuvant, 67 palliative therapy for advanced/metastatic disease). The most common neoadjuvant regimens used were FOLFIRINOX (n = 9) and gemcitabine/nab-paclitaxel (n = 7). Reported responses in the neoadjuvant setting (n = 26) included 10 with stable disease (SD), 11 partial response (PR) and 5 progressive disease (PD). The most common regimens used in the first line advanced setting were FOLFIRINOX (n = 18), gemcitabine/nab-paclitaxel (n = 9), and gemcitabine (n = 8). Of 55 responses recorded there were 13 SD, 15 PR, 25 PD and 2 complete responses (CR). Of the patients who received first line therapy, 54% (n = 36), 15% (n = 10) and 6% (n = 4) went on to receive second, third or fourth line therapy, respectively. 118 patients (76.13%) had a reported date of death. Of the 98 patients who received definitive surgical resection the median recurrence free survival (mRFS) and overall survival (mOS) was 7.36 and 14.17 months, respectively. Of the 44 patients that presented with de novo unresectable or metastatic disease, mOS was 7.53 months. The mOS of advanced disease patients from the time of receipt of first line palliative chemotherapy was 8.45 months. Molecular panels revealed mutation frequencies of common somatic and DNA repair genes in similar frequency to pancreatic adenocarcinoma. The mean tumor mutation burden of 18 patients was 4.7 with a max of 27. Of 27 patients who received MMR/MSI testing 100% were pMMR/MSS. Conclusions: This is one of the largest single center series of ASQ patients reported and describes unique findings related to neoadjuvant and advanced disease treatment experience. Overall this study confirms the continued poor survival and poor response to standard regimens in this disease suggesting we should consider alternative treatment paradigms.