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.

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.

A novel tool to predict nodal metastasis in small pancreatic neuroendocrine tumors: A multicenter study

BACKGROUND

Nonfunctional pancreatic neuroendocrine tumors display a wide range of biological behavior, and nodal disease is associated with metastatic disease and poorer survival. The aim of this study was to develop a tool to predict nodal disease in patients with small (≤2 cm) nonfunctional pancreatic neuroendocrine tumors.

METHODS

A multicenter retrospective study was performed on patients undergoing resection for small nonfunctional pancreatic neuroendocrine tumors. Patients with genetic syndromes, metastatic disease at diagnosis, neoadjuvant therapy, or positive resection margin were excluded. Factors associated with nodal disease were identified to develop a predictive model. Internal validation was performed using bootstrap with 1,000 resamples.

RESULTS

Nodal disease was observed in 39 (11.1%) of the 353 patients included. Presence of nodal disease was significantly associated with lower 5-year disease-free survival (71.6% vs 96.2%, P < .001). Two predictors were strongly associated with nodal disease: G2 grade (odds ratio: 3.51, 95% confidence interval: 1.71-7.22, P = .001) and tumor size (per mm increase, odds ratio: 1.14, 95% confidence interval: 1.03-1.25, P = .009). Adequate discrimination was observed with an area under the curve of 0.71 (95% confidence interval: 0.63-0.80). Based on risk distribution, 3 risk groups of nodal disease were identified; low (<5%), intermediate (≥5% to <20%), and high (≥20%) risk. The observed mean risk of nodal disease was 3.7% in the low-risk patients, 9.6% in the intermediate-risk patients, and 30.4% in the high-risk patients (P < .001). The 10-year disease-free survival in the low, intermediate, and high-risk groups was 100%, 88.8%, and 50.1%, respectively.

CONCLUSION

Our model using tumor grade and size can predict nodal disease in small nonfunctional pancreatic neuroendocrine tumors. Integration of this tool into clinical practice could help guide management of these patients.

Classification of pancreatic cystic neoplasms using radiomic feature analysis is equivalent to an experienced academic radiologist: a step toward computer-augmented diagnostics for radiologists

PURPOSE

A wide array of benign and malignant lesions of the pancreas can be cystic and these cystic lesions can have overlapping imaging appearances. The purpose of this study is to compare the diagnostic accuracy of a radiomics-based pancreatic cyst classifier to an experienced academic radiologist.

METHODS

In this IRB-approved retrospective single-institution study, patients with surgically resected pancreatic cysts who underwent preoperative abdominal CT from 2003 to 2016 were identified. Pancreatic cyst(s) and background pancreas were manually segmented, and 488 radiomics features were extracted. Random forest classification based on radiomics features, age, and gender was evaluated with fourfold cross-validation. An academic radiologist blinded to the final pathologic diagnosis reviewed each case and provided the most likely diagnosis.

RESULTS

214 patients were included (64 intraductal papillary mucinous neoplasms, 33 mucinous cystic neoplasms, 60 serous cystadenomas, 24 solid pseudopapillary neoplasms, and 33 cystic neuroendocrine tumors). The radiomics-based machine learning approach showed AUC of 0.940 in pancreatic cyst classification, compared with AUC of 0.895 for the radiologist.

CONCLUSION

Radiomics-based machine learning achieved equivalent performance as an experienced academic radiologist in the classification of pancreatic cysts. The high diagnostic accuracy can potentially maximize the efficiency of healthcare utilization by maximizing detection of high-risk lesions.

Predictors, Patterns, and Timing of Recurrence Provide Insight into the Disease Biology of Invasive Carcinomas Arising in Association with Intraductal Papillary Mucinous Neoplasms

OBJECTIVES

To identify predictors, patterns, and timing of recurrence after resection of invasive carcinomas arising in association with an IPMN.

BACKGROUND

Postoperative management of an invasive carcinoma arising in association with an intraductal papillary mucinous neoplasm (IPMN), a biologically distinct entity from PanIN-derived pancreatic ductal adenocarcinoma (PDAC), remains largely based on guidelines for PanIN-derived PDAC. To minimize treatment failure and inform disease-specific management, cancer recurrence must be better characterized.

METHODS

Patients were identified from a prospectively maintained registry between 1996 and 2018. Predictors of recurrence were evaluated by employing Cox regression models to determine risk-adjusted hazard ratios (HR) with 95% confidence intervals (95%CI). The patterns and timing of recurrence were recognized and compared utilizing a log-rank test, respectively.

RESULTS

Of the 213 patients included, 92 (43.2%) recurred with a median RFS of 23.7 months (16.7-30.7). The predominant pattern of recurrence included any systemic (65.2%). The median time to local recurrence was longer than systemic (21.6 versus 11.4 months, p = 0.05). Poor differentiation [HR: 3.01, 95%CI (1.06-8.61)] and nodal disease [N1, HR: 2.23, 95%CI (1.12-4.60); and N2, HR: 5.67 95%CI (2.93-10.99)] emerged as independent predictors of systemic recurrence. For local-specific recurrences, poor differentiation [HR: 3.73, 95%CI (1.04-13.45)] and an R1 margin [high-grade dysplasia or invasive carcinoma; HR: 2.66, 95%CI (1.14-6.21)] emerged as independent predictors.

CONCLUSIONS

The predominant pattern of recurrence after resection of invasive carcinomas arising in association with IPMNs is systemic, and occurs earlier than local recurrence. Poor differentiation and nodal disease are associated with systemic recurrence while poor differentiation and an R1 margin are associated with local recurrence. Future studies should investigate the role of systemic (chemotherapy) versus local (radiation) therapies and surveillance strategies in a personalized manner.

Cinematic Rendering: Novel Tool for Improving Pancreatic Cancer Surgical Planning

Pancreatic ductal adenocarcinoma is the third-leading cause of all cancer-related deaths in the US. While 20% of patients have resectable disease at diagnosis, improved control of systemic disease using effective chemotherapeutic regimens allows for aggressive operations involving complex vascular resection and reconstruction. A pancreas protocol computed tomography (PPCT) is the gold standard imaging modality in determining local resectability (degree of tumor-vessel involvement), however, it is limited by the inter-operator variability. While post-processing-3D-rendering helps, it does not allow for real-time dynamic assessment of resectability. A recent development in post-process-rendering called cinematic rendering (CR) overcomes this by utilizing advanced light modeling to generate photorealistic 3D images with enhanced details. Cinematic rendering allows for nuanced visualization of areas of interest. Our preliminary experience, as one of the first centers to incorporate the routine use of CR, has proven very useful in surgical planning. For local determination of resectability, vascular mapping allows for accurate assessment of major arteries and the portovenous system. For the portovenous anatomy it assists in determining the optimal surgical approach (extent of resection, appropriate technique for reconstruction, and need for mesocaval shunting). For arterial anatomy, vessel encasement either represents dissectible involvement via periadventitial dissection or true vessel invasion that is unresectable. CR could potentially provide superior ability than traditional PPCT to discern between the two. Additionally, CR allows for better 3D visualization of arterial anatomic variants which, if not appreciated preoperatively, increases risk of intraoperative ischemia and postoperative complications. Lastly, CR could help avoid unnecessary surgery by enhanced identification of occult metastatic disease that is metastatic disease that is otherwise not appreciated on a standard PPCT.

Long-term Outcomes of Parenchyma-sparing and Oncologic Resections in Patients With Nonfunctional Pancreatic Neuroendocrine Tumors <3 cm in a Large Multicenter Cohort

INTRODUCTION

The role of parenchyma-sparing resections (PSR) and lymph node dissection in small (<3 cm) nonfunctional pancreatic neuroendocrine tumors (PNET) is unlikely to be studied in a prospective randomized clinical trial. By combining data from 4 high-volume pancreatic centers we compared postoperative and long-term outcomes of patients who underwent PSR with patients who underwent oncologic resections.

METHODS

Retrospective review of prospectively collected clinicopathologic data of patients who underwent pancreatectomy between 2000 and 2021 was collected from 4 high-volume institutions. PSR and lymph node-sparing resections (enucleation and central pancreatectomy) were compared to those who underwent oncologic resections with lymphadenectomy (pancreaticoduodenectomy, distal pancreatectomy). Statistical testing was performed using χ 2 test and t test, survival estimates with Kaplan-Meier method and multivariate analysis using Cox proportional hazard model.

RESULTS

Of 810 patients with small sporadic nonfunctional PNETs, 121 (14.9%) had enucleations, 100 (12.3%) had central pancreatectomies, and 589 (72.7%) patients underwent oncologic resections. The median age was 59 years and 48.2% were female with a median tumor size of 2.5 cm. After case-control matching for tumor size, 221 patients were selected in each group. Patients with PSR were more likely to undergo minimally invasive operations (32.6% vs 13.6%, P <0.001), had less intraoperative blood loss (358 vs 511 ml, P <0.001) and had shorter operative times (180 vs 330 minutes, P <0.001) than patients undergoing oncologic resections. While the mean number of lymph nodes harvested was lower for PSR (n=1.4 vs n=9.9, P <0.001), the mean number of positive lymph nodes was equivalent to oncologic resections (n=1.1 vs n=0.9, P =0.808). Although the rate of all postoperative complications was similar for PSR and oncologic resections (38.5% vs 48.2%, P =0.090), it was higher for central pancreatectomies (38.5% vs 56.6%, P =0.003). Long-term median disease-free survival (190.5 vs 195.2 months, P =0.506) and overall survival (197.9 vs 192.6 months, P =0.372) were comparable. Of the 810 patients 136 (16.7%) had no lymph nodes resected. These patients experienced less blood loss, shorter operations ( P <0.001), and lower postoperative complication rates as compared to patients who had lymphadenectomies (39.7% vs 56.9%, P =0.008). Median disease-free survival (197.1 vs 191.9 months, P =0.837) and overall survival (200 vs 195.1 months, P =0.827) were similar for patients with no lymph nodes resected and patients with negative lymph nodes (N0) after lymphadenectomy.

CONCLUSION

In small <3 cm nonfunctional PNETs, PSRs and lymph node-sparing resections are associated with lower blood loss, shorter operative times, and lower complication rates when compared to oncologic resections, and have similar long-term oncologic outcomes.

Implications of Perineural Invasion on Disease Recurrence and Survival After Pancreatectomy for Pancreatic Head Ductal Adenocarcinoma

OBJECTIVE

To describe PNI and to evaluate its impact on disease-free (DFS) and overall survival (OS) in patients with resected pancreatic ductal adenocarcinoma (PDAC).

SUMMARY OF BACKGROUND DATA

Although PNI is a prognostic factor for survival in many GI cancers, there is limited knowledge regarding its impact on tumor recurrence, especially in ''early stage disease'' (PDAC ≤20 mm, R0/ N0 PDAC).

METHODS

This multicenter retrospective study included patients undergoing PDAC resection between 2009 and 2014. The association of PNI with DFS and OS was analyzed using Cox proportional-hazards models.

RESULTS

PNI was found in 87% of 778 patients included in the study, with lower rates in PDAC ≤20 mm (78.7%) and in R0/N0 tumors (70.6%). PNI rate did not differ between patients who underwent neoadjuvant therapy and upfront surgery (88% vs 84%, P = 0.08). Although not significant at multivariate analysis ( P = 0.07), patients with PNI had worse DFS at univariate analysis (median DFS: 20 vs 15 months, P < 0.01). PNI was the only independent predictor of DFS in R0/N0 tumors (hazard ratio [HR]: 2.2) and in PDAC ≤ 20 mm (HR: 1.8). PNI was an independent predictor of OS in the entire cohort (27 vs 50 months, P = 0.01), together with G3 tumors, pN1 status, carbohydrate antigen (CA) 19.9 >37 and pain.

CONCLUSIONS

PNI represents a major determinant of tumor recurrence and patients' survival in pancreatic cancer. The role of PNI is particularly relevant in early stages, supporting the hypothesis that invasion of nerves by cancer cells has a driving role in pancreatic cancer progression.

Association of Matrix Metalloproteinase 7 Expression With Pathologic Response After Neoadjuvant Treatment in Patients With Resected Pancreatic Ductal Adenocarcinoma

Importance

The use of neoadjuvant therapy (NAT) in resectable pancreatic ductal adenocarcinoma (PDAC) remains controversial. A favorable pathologic response (complete or marked tumor regression) to NAT is associated with better outcomes in patients with resected PDAC. The role of NAT for early systemic control compared with immediate surgical resection for PDAC is under investigation. In the era of precision medicine, biomarkers for patient selection and prediction of therapy response are crucial.

Objective

To evaluate the use of assessment for protein expression on fine-needle aspiration (FNA) biopsy specimens in predicting pathologic response to NAT in treatment-naive patients.

Design, Setting, and Participants

This was a single-institution prognostic study from a high-volume center for pancreatic cancer. All specimens were obtained between January 1, 2009, and December 31, 2018, with a median (SE) follow-up of 20.2 (1.4) months. Analysis of the data was performed from October 1, 2019, to April 30, 2021. Targeted RNA sequencing of frozen FNA biopsy specimens from a discovery cohort of 23 patients was performed to identify genes with aberrant expression that was associated with patients' pathologic response to NAT. Immunohistochemical staining was performed on an additional 80 FNA biopsy specimens to assess expression of matrix metalloproteinase 7 (MMP-7) and its association with pathologic response. Receiver operating characteristic curves for prediction of favorable pathologic response were determined.

Results

In the discovery cohort (12 [52.1%] male; 3 [13.0%] Black and 20 [86.9%] White), RNA sequencing showed that lower MMP-7 expression was associated with favorable pathologic response (College of American Pathologists system scores of 0 [complete response] and 1 [marked response]). In the validation cohort (40 [50.0%] female; 9 [11.3%] Black and 71 [88.7%] White), patients with negative MMP-7 expression were significantly more likely to have a favorable pathologic response (odds ratio, 21.25; 95% CI, 6.19-72.95; P = .001). Receiver operating characteristic curves for prediction of favorable pathologic response from multivariable Cox proportional hazards regression modeling showed that MMP-7 expression increased the area under the curve from 0.726 to 0.906 (P < .001) even after stratifying by resectability status. The positive predictive value and negative predictive value of MMP-7 protein expression on FNA biopsy specimens in predicting unfavorable pathologic response (scores of 2 [partial response] or 3 [poor or no response]) were 88.2% and 73.9%, respectively.

Conclusions and Relevance

Assessment of MMP-7 expression on FNA biopsy specimens at the time of diagnosis may help identify patients who would benefit the most from NAT.

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.

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.

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.

Favorable tumor biology in locally advanced pancreatic cancer-beyond CA19-9

Patients with pancreatic ductal adenocarcinoma (PDAC) are frequently staged as unresectable locally advanced pancreatic cancer (LAPC) at the time of diagnosis. Recently, the administration of multi-agent induction chemotherapy has resulted in treatment response in up to 60% of these patients rendering their tumors technically resectable. Operative strategies have evolved to allow for successful oncologic resection of LAPC. These technically complex procedures involving vascular resections and reconstructions are now being performed with increasing safety at high-volume centers. However, even after induction therapy and successful resection, disease recurrence sometimes occurs early on, limiting the benefit of resecting the local tumor. Therefore, selection of surgical candidates should factor in each patient's tumor biology which could result in accurate treatment guidance to improve patient outcomes while avoiding overtreatment. Well-informed patient selection is critical to improve outcomes in LAPC. Multidisciplinary teams have to determine the appropriate care for LAPC patients at the time of reevaluation after administration of induction chemotherapy. At this point the concept of favorable vs. unfavorable tumor biology becomes highly relevant and having access to biomarkers that are predictive of tumor behavior are of paramount importance. Currently, CA19-9 remains the only clinically utilized biomarker for PDAC, however, its use is limited by factors discussed in this review. While CA19-9 holds value in patient assessment, additional biomarkers are required that could supplement and improve the current ability to classify tumor biology and predict behavior in individual patients. Recent investigations on the use of circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) using liquid biopsies, as well as patient-derived organoids to characterize tumor biology have shown promise in achieving precise tumor biology-based patient stratification. Serial assessment of these biomarkers throughout therapy could supplement or even replace the anatomic criteria for resectability in the future.

Comprehensive Analysis of Somatic Mutations in Driver Genes of Resected Pancreatic Ductal Adenocarcinoma Reveals KRAS G12D and Mutant TP53 Combination as an Independent Predictor of Clinical Outcome

BACKGROUND

Prognosis in pancreatic ductal adenocarcinoma (PDAC) remains poor despite improved systemic therapies and surgical techniques. The identification of biomarkers to advance insight in tumor biology and achieve better individualized prognostication could help improve outcomes. Our aim was to elucidate the prognostic role of the four main driver mutations (KRAS, TP53, SMAD4, CDKN2A) and their combinations in resected PDAC.

PATIENTS AND METHODS

A retrospective analysis was conducted utilizing the cBioPortal database and National Cancer Institute's Cancer Genomic Atlas (TCGA) on patients in whom next-generation sequencing was performed on upfront resected PDAC from 2012 to 2020. Multivariable Cox regression was implemented to elucidate risk-adjusted predictors of overall (OS) and recurrence-free survival (RFS). Results were validated employing a Johns Hopkins Hospital (JHH) cohort.'

RESULTS

In the discovery cohort (n = 587), increased number of mutated driver genes was associated with worse OS (p = 0.047). Specifically, patients with mutations in ≥ 2 driver genes had worse OS than ≤ 1 mutated gene (18.2 versus 32.3 months, p = 0.033). Co-occurrence of mutant (mt)KRAS p.G12D with mtTP53 (median OS, 25.9 months) conferred better prognosis than co-occurrence of other mtKRAS variants (p.G12V/R/other) with mtTP53 (median OS, 16.9 months, p = 0.038). The findings were validated using a JHH cohort. Multivariable risk-adjustment found co-occurrence of mtKRAS p.G12D with mtTP53 to be an independent predictor of beneficial OS and RFS [HR (95% CI): 0.18 (0.03-0.81) and 0.31 (0.11-0.89) respectively].

CONCLUSION

In chemo-naïve resected PDAC, combinations of mutations in the four driver genes are associated with prognosis. In patients with combined mtKRAS and mtTP53, KRAS p.G12D variant confers a better OS and RFS.

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.

Technical progress in robotic pancreatoduodenectomy: TRIANGLE and periadventitial dissection for retropancreatic nerve plexus resection

PURPOSE

The resection of retropancreatic nerve plexuses for pancreatic head cancer became standard of care during open pancreatoduodenectomy to minimize local recurrences. Since more surgical centers are progressing on the learning curve, robotically-assisted pancreatoduodenectomy is now increasingly performed with decreasing anatomic exclusion criteria. To achieve comparable and favorable oncologic outcomes, advanced surgical techniques should be transferred and implemented when performing robotic resections.

METHODS

The nomenclature and anatomic principles of retropancreatic nerve plexuses and three different levels of dissections are utilized based on established definitions.

RESULTS

The en bloc dissection in the "TRIANGLE" area (triangular-shaped retropancreatic space enclosed by the common hepatic artery, superior mesenteric artery, and superior mesenteric vein/portal vein) and the periadventitial dissection of arteries for non-tunica media-invading tumors were executed robotically. Both can be utilized to achieve a radical dorsal and medial margin. Video recordings are provided to illustrate varying TRIANGLE dissections.

CONCLUSION

To accomplish oncologic non-inferiority, established principles from open pancreatic resections can be incorporated precisely and safely, overcoming the lack of haptic feedback while exploiting the technological advantages of the robotically-assisted platform.

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.

Progression vs Cyst Stability of Branch-Duct Intraductal Papillary Mucinous Neoplasms After Observation and Surgery

Importance

The progression of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas to malignant disease is still poorly understood. Observational and surgical series have failed to provide comprehensive information.

Objective

To identify dynamic variables associated with the development of malignant neoplasms by combining pathological features with data from preoperative repeated observations.

Design, Setting, and Participants

The Crossover Observational Multicentric Study included a retrospective cohort of patients with branch-duct IPMNs (BD IPMNs) enrolled in a surveillance program from January 1, 2000, to December 31, 2019. Patients were enrolled from 5 referral centers: the Pancreas Institute, Verona, Italy; Seoul National University Hospital, Seoul, South Korea; Singapore General Hospital, Singapore; Johns Hopkins School of Medicine, Baltimore, Maryland; and University of Texas MD Anderson Cancer Center, Houston. Patients underwent a minimum of 12 months of preoperative surveillance (median, 37 [interquartile range (IQR), 20-68] months).

Main Outcomes and Measures

Dynamic variables associated with malignant disease were explored to estimate the presence of high-grade dysplasia (HGD) and invasive cancer at final pathological examination.

Results

A total of 292 patients were included in the analysis (137 women [46.9%] and 155 men [53.1%]; median age, 64 [IQR, 56-71] years). During surveillance, 27 patients (9.2%) developed a worrisome feature after 5 years, and 46 of 276 (16.7%) developed high-risk stigmata (HRS). At final pathological evaluation, 107 patients (36.6%) had HGD or invasive cancer, and 16 (5.5%) had IPMNs with concomitant pancreatic ductal adenocarcinoma. Rates of HGD and invasive cancer at pathological evaluation significantly differed between those without worrisome features and those developing HRS from a previous worrisome feature (9 [27.3%] vs 13 [61.9%]; P < .001). Developing an additional worrisome feature during surveillance (odds ratio [OR], 3.24 [95% CI, 1.38-7.60]; P = .007) or an HRS from a baseline worrisome feature (OR, 2.87 [95% CI, 1.01-8.17]; P = .048) was associated with HGD at final pathological evaluation. Among HRS, development of jaundice on a low-risk cyst was independently associated with invasive cancer (OR, 16.04 [95% CI, 2.94-87.40]; P = .001).

Conclusions and Relevance

These findings suggest that in BD IPMNs under surveillance, harboring a stable worrisome feature carries the lowest risk of malignant disease. Development of additional worrisome features or HRS is associated with the presence of HGD, whereas the occurrence of jaundice is associated with invasive cancer.

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.