Outcome after surgery for invasive intraductal papillary mucinous neoplasia compared to conventional pancreatic ductal adenocarcinoma - A Swedish nationwide register-based study

The role of national population-based registries in pancreatic cancer surgery research

Research and innovation are critical for advancing the multidisciplinary management of pancreatic cancer. Registry-based studies (RBSs) are a complement to randomized clinical trials (RCTs). Compared with RCTs, RBSs offer cost-effectiveness, larger sample sizes, and representation of real-world clinical practice. National population-based registries (NPBRs) aim to cover the entire national population, and studies based on NPBRs are, compared to non-NPBRs, less prone to selection bias. The last decade has witnessed a dramatic increase in NPBRs in pancreatic cancer surgery, which has undoubtedly added invaluable knowledge to the body of evidence on pancreatic cancer management. However, several methodological shortcomings may compromise the quality of registry-based studies. These include a lack of control over data collection and a lack of reporting on the quality of the source registry or database in terms of validation of coverage and data completeness and accuracy. Furthermore, there is a significant risk of double publication from the most commonly used registries as well as the inclusion of historical data that is not relevant or representative of research questions addressing current practices.

Pancreas 2000. My journey with the central organ

The European Pancreatic Club Lifetime Achievement Award is a distinction awarded for research on the pancreas and service to European Pancreatology. It comes with the obligation to submit a review article to our society's journal, Pancreatology. It was awarded to me 2023 and I take this opportunity to highlight my journey with the central organ AKA the pancreas, that is inseparatable from "Pancreas 2000" - an educational program for future pancreatologists, inaugurated by Karolinska Institutet.

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Clinical characteristics and survival prediction of surgical patients with invasive pancreatic cystic neoplasm: a large retrospective study over two decades

PURPOSES

Invasive pancreatic cystic neoplasms (iPCNs) are an uncommon and biologically heterogeneous group of malignant neoplasms. We aimed to investigate the clinicopathological characteristics of iPCN patients and to develop nomograms for individual survival prediction after radical surgery.

METHODS

Data of patients diagnosed with iPCN and pancreatic ductal adenocarcinoma (PDAC) between 2000 and 2018 from the SEER database were retrieved. The differences in clinical outcomes were evaluated using the Kaplan-Meier analysis. Nomograms were proposed based on the Cox regression model and internally validated by C-index, area under the curve (AUC) value, and calibration plot.

RESULTS

A total of 7777 iPCN patients and 154,336 PDAC patients were enrolled. Most neoplasms were advanced, with 63.1% at stage IV. The 3-year overall survival (OS) and cancer-specific survival (CSS) rates in surgical patients were as follows: 45.7% and 50.1% for invasive intraductal papillary mucinous neoplasm (IPMN), 54.8% and 59.3% for invasive mucinous cystic neoplasm (MCN), 97.8% and 98.2% for invasive solid pseudopapillary neoplasm (SPN), 88.9% and 88.9% for invasive serous cystic neoplasm (SCN), and 27.3% and 30.5% for PDAC. Subgroup analyses showed no clinical benefit from chemotherapy or radiotherapy in lymph node-negative iPCN patients who underwent surgery. The following variables associated with OS and CSS were identified: age, race, chemotherapy, radiotherapy, histologic type, pathological grade, regional nodes examined, and T, N, and M stage. The nomograms had good discrimination and calibration by internal validation, with an AUC value of 0.800 for 3-year OS and 0.814 for 3-year CSS.

CONCLUSION

Our study showed that the prognosis of iPCN patients was significantly better than PDAC patients. The proposed nomograms demonstrated substantially better discrimination and calibration.

N-glycosylation in non-invasive and invasive intraductal papillary mucinous neoplasm

Intraductal papillary mucinous neoplasms (IPMNs), often found incidentally, are potentially malignant cystic tumors of the pancreas. Due to the precancerous nature, IPMNs lacking malignant features should be kept on surveillance. The follow-up relies on magnetic resonance imaging, which has a limited accuracy to define the high-risk patients. New diagnostic methods are thus needed to recognize IPMNs with malignant potential. Here, aberrantly expressed glycans constitute a promising new area of research. We compared the N-glycan profiles of non-invasive IPMN tissues (n = 10) and invasive IPMN tissues (n = 10) to those of non-neoplastic pancreatic controls (n = 5) by matrix-assisted laser desorption-ionization time-of-flight (MALDI-TOF) mass spectrometry. Both IPMN subgroups showed increased abundance of neutral composition H4N4 and decrease in H3N5F1, increase in sialylation, and decrease in sulfation, as compared to the controls. Furthermore, invasive IPMN showed an increase in terminal N-acetylhexosamine containing structure H4N5, and increase in acidic complex-type glycans, but decrease in their complex fucosylation and sulfation, as compared to the controls. In conclusion, the N-glycan profiles differed between healthy pancreatic tissue and non-invasive and invasive IPMNs. The unique glycans expressed in invasive IPMNs may offer interesting new options for diagnostics.

Pre-emptive resection for intraductal papillary mucinous neoplasia - Long-term outcome is similar between non-invasive and early invasive lesions in a tertiary single center

BACKGROUND

Pre-emptive resection for intraductal papillary mucinous neoplasm (IPMN) aims to reduce the risk before invasive transformation has taken place. Pancreatic resections are highly associated with major morbidity and mortality. Long-term overall survival (OS) after resection for invasive IPMN (inv-IPMN) in early stages is favorable. Comparison of long-term OS for resected non-invasive IPMN and early staged inv-IPMN is poorly delineated. This study aims to compare outcomes for resected non-invasive IPMN and T1-staged inv-IPMN.

METHODS

All patients ≥18 years of age resected for IPMN up to stage T1 at Karolinska University Hospital between 2008 and 2020 were included. Two-year OS were compared between groups by chi-squared test, and 5-year OS was estimated using Kaplan-Meier method. Covariates associated with death was assessed in multivariable Cox regression model.

RESULTS

We included 284 patients, 264 (93%) non-invasive IPMN and 20 (7%) T1-staged inv-IPMN. Dysplasia of low grade (LGD) and high grade, i.e., tumor in situ (Tis) were present in 190 (67%) and 75 (26%) patients respectively. The 2-year OS for the entire cohort was 96%, and there were no differences between non-invasive and inv-IPMN (96% vs 92%, p = 0.203), nor between IPMN with LGD and Tis-T1b-staged IPMN (96% vs 95%, p = 0.734).

CONCLUSION

Two thirds of the specimen from pre-emptive resections were of LGD and did not involve superior OS than in situ or early cancer. Due to high complication burden, efforts should be made to avoid resection when LGD is probable and rather identify more accurate predictors for surgery.