[A rare case of intraductal tumor of the pancreas in which an intraductal tubulopapillary neoplasm was mixed with a widely spreading gastric-type intraductal papillary-mucinous neoplasm].

A 70-year-old man receiving treatment for diabetes mellitus presented with a cystic mass in the border area of the pancreatic body and tail on plain computed tomography (CT) due to impaired glucose intolerance. Contrast-enhanced CT showed a faint hyperattenuated nodular mass extending from the dilated main pancreatic duct (MPD) to the branch duct. Endoscopic retrograde cholangiopancreatography revealed a mildly dilated orifice of the papilla of Vater and MPD stenosis with entire upstream and immediate downstream dilatations. The patient underwent distal pancreatectomy due to the suspicion of mixed-type intraductal papillary-mucinous carcinoma. A pathological examination showed an intraductal solid-nodular mass measuring 25mm in length, consisting of two types of neoplasms. One showed tubulopapillary growth with entirely high-grade (HG) atypical cuboidal epithelium, in which immunohistochemical examinations were positive for MUC6 but negative for human gastric mucin (HGM), MUC1, MUC2, and MUC5AC, fitting the concept of intraductal tubulopapillary neoplasm (ITPN). The other showed the same growth of low-grade (LG) atypical columnar cells positive for HGM and MUC5AC and negative for MUC1 and MUC2, which corresponded to gastric-type intraductal papillary-mucinous neoplasm (IPMN) -LG. The tumor had not invaded the duct walls, and no metastatic lymph nodes were observed. The ITPN was adjacent to the IPMN mainly composed of tubular glands mimicking pyloric glands with LG dysplasia that corresponded to the so-called IPMN-pyloric gland variant. Moreover, the proliferation of low-papillary gastric-type IPMN spread around the intraductal tumors. Consequently, the patient was diagnosed with an intraductal tubular neoplasm comprising a noninvasive ITPN and gastric-type IPMN-LG. ITPN is a recently identified intraductal neoplasm of the pancreas proposed by Yamaguchi et al. and is distinguished by intraductal tubulopapillary growth with HG cellular atypia without overt mucin production, in contrast to IPMN. To date, no cases of intraductal nodular tumors comprising ITPN and IPMN have been reported. We report this original case with imaging and pathological observations and discuss potential processes via which ITPN and IPMN may arise adjacent to each other in the same pancreatic duct.

Pancreatoscopy-Guided Endotherapies for Pancreatic Diseases.

Per-oral pancreatoscopy (POP) is a pancreas-preserving modality that allows for targeted pancreatic duct interventions, particularly in cases where standard techniques fail. POP specifically has an emerging role in the diagnosis, risk stratification, and disease extent determination of main duct intraductal papillary mucinous neoplasms (IPMNs). It has also been successfully used for laser ablation of IPMNs in poor surgical candidates, lithotripsy for complex stone disease, and laser stricturoplasty. As experience with POP increases beyond select referral center practices, further studies validating POP efficacy with long-term follow-up will help clarify when POP-guided intervention is most beneficial in relation to surgical intervention.

Adjuvant chemotherapy for adenocarcinoma arising from intraductal papillary mucinous neoplasia: multicentre ADENO-IPMN study.

BACKGROUND: The clinical impact of adjuvant chemotherapy after resection for adenocarcinoma arising from intraductal papillary mucinous neoplasia is unclear. The aim of this study was to identify factors related to receipt of adjuvant chemotherapy and its impact on recurrence and survival. METHODS: This was a multicentre retrospective study of patients undergoing pancreatic resection for adenocarcinoma arising from intraductal papillary mucinous neoplasia between January 2010 and December 2020 at 18 centres. Recurrence and survival outcomes for patients who did and did not receive adjuvant chemotherapy were compared using propensity score matching. RESULTS: Of 459 patients who underwent pancreatic resection, 275 (59.9%) received adjuvant chemotherapy (gemcitabine 51.3%, gemcitabine-capecitabine 21.8%, FOLFIRINOX 8.0%, other 18.9%). Median follow-up was 78 months. The overall recurrence rate was 45.5% and the median time to recurrence was 33 months. In univariable analysis in the matched cohort, adjuvant chemotherapy was not associated with reduced overall (P = 0.713), locoregional (P = 0.283) or systemic (P = 0.592) recurrence, disease-free survival (P = 0.284) or overall survival (P = 0.455). Adjuvant chemotherapy was not associated with reduced site-specific recurrence. In multivariable analysis, there was no association between adjuvant chemotherapy and overall recurrence (HR 0.89, 95% c.i. 0.57 to 1.40), disease-free survival (HR 0.86, 0.59 to 1.30) or overall survival (HR 0.77, 0.50 to 1.20). Adjuvant chemotherapy was not associated with reduced recurrence in any high-risk subgroup (for example, lymph node-positive, higher AJCC stage, poor differentiation). No particular chemotherapy regimen resulted in superior outcomes. CONCLUSION: Chemotherapy following resection of adenocarcinoma arising from intraductal papillary mucinous neoplasia does not appear to influence recurrence rates, recurrence patterns or survival.

CT findings and clinical effects of high grade pancreatic intraepithelial neoplasia in patients with intraductal papillary mucinous neoplasms.

PURPOSE: To investigate the common CT findings of high-grade (HG) PanIN and clinical effects in the remnant pancreas in patients with intraductal papillary mucinous neoplasm (IPMN) of the pancreas. MATERIALS AND METHODS: Two hundred fifty-one patients with surgically confirmed IPMNs (118 malignant [invasive carcinoma/high-grade dysplasia] and 133 benign [low-grade dysplasia]) were retrospectively enrolled. The grade of PanIN (233 absent/low-grade and 18 high-grade) was recorded, and all patients underwent serial CT follow-up before and after surgery. Two radiologists analyzed CT findings of high-risk stigmata or worrisome features according to 2017 international consensus guidelines. They also analyzed tumor recurrence on serial follow-up CT after surgery. Statistical analyses were performed to identify significant predictors and clinical impact on postoperative outcomes of HG PanIN. RESULTS: PanIN grade showed a significant association with IPMN grade (p = 0.012). Enhancing mural nodules ≥5 mm, abrupt main pancreatic duct (MPD) changes with distal pancreatic atrophy, increased mural nodule size and MPD diameter were common findings in HG PanIN (P<0.05). In multivariate analysis, abrupt MPD change with distal pancreatic atrophy (odds ratio (OR) 6.59, 95% CI: 2.32-18.72, <0.001) and mural nodule size (OR, 1.05; 95% CI, 1.02-1.08, 0.004) were important predictors for HG PanIN. During postoperative follow-up, HG PanIN (OR, 4.98; 95% CI, 1.22-20.33, 0.025) was significantly associated with cancer recurrence in the remnant pancreas. CONCLUSION: CT can be useful for predicting HG PanIN using common features, such as abrupt MPD changes and mural nodules. In HG PanIN, extra caution is needed to monitor postoperative recurrence during follow-up.

The diagnostic value of abbreviated MRI protocol in the surveillance of Branch-Duct intraductal papillary mucinous neoplasm.

PURPOSE: To assess the diagnostic value of abbreviated protocol (AP) MRI to detect the degeneration signs in branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) in patients undergoing a routine MRI follow-up. METHODS: This dual-center retrospective study include patients with BD-IPMN diagnosed on initial comprehensive protocol (CP) MRI who underwent routine MRI follow-up. CP included axial and coronal T2-weighted images (T2WI), axial T1-weighted images (T1WI) before and after contrast administration, 3D MR cholangiopancreatography (MRCP) and diffusion-weighted images (DWI). Two APs, eliminating dynamic sequences ± DWI, were extracted from CP. Two radiologists evaluated the APs separately for IPMN degeneration signs according to Fukuoka criteria and compared the results to the follow-up CP. In patients who underwent EUS, imaging findings were correlated with pathological results. Per-patient and per-lesion sensitivity, specificity, PPV, NPV, and accuracy of APs were calculated. Additionally, the acquisition time for different protocols was calculated. RESULTS: One hundred-fourteen patients (56.1 % women, median age: 71 years) with 256 lesions were included. Degeneration signs were observed in 24.6 % and 12.1 % per-patient and per-lesion, respectively. Regarding APs, the per patient sensitivity, specificity, PPV, NPV, and accuracy in the detection of the degeneration signs were 100 %, 93.5 %, 83.3 %, 100 %, and 95.1 %, respectively. No additional role for DWI was detected. AP without DWI economized nearly half of CP acquisition time (388 versus 663 s, respectively). CONCLUSION: AP can confidently replace CP for BD-IPMN follow-up with high sensitivity and PPV while offering benefits such as patient comfort, improved MRI accessibility, and reduced dedicated time for image analysis. DWI necessitates special consideration. CLINICAL RELEVANCE STATEMENT: Our data suggest that APs safely detect all degeneration signs of IPMN. While there is an overestimation of mural nodules due to the lack of contrast injection, this occurs in a negligible number of patients.

Total pancreatectomy, splenectomy and remnant gastrectomy for invasive intraductal papillary mucinous neoplasm (IPMN) after prior Roux-en-Y gastric bypass.

A female patient in her 50s presented with abdominal pain, nausea and jaundice. She had a history of prior Roux-en-Y gastric bypass and her body mass index was 52.5 kg/m2 Biochemical testing revealed a total bilirubin level of 14.3 mg/dL (normal<1.2 mg/dL) and carbohydrate antigen 19-9 of 38.3 units/mL (normal<36.0 units/mL). CT demonstrated a 3.2 cm pancreatic head mass, biliary and pancreatic duct dilation and cystic replacement of the pancreas. The findings were consistent with a diagnosis of mixed-type intraductal papillary mucinous neoplasm (IPMN) with invasive malignancy. The patient's Roux-en-Y anatomy precluded endoscopic biopsy, and she underwent upfront resection with diagnostic laparoscopy, open total pancreatectomy, splenectomy and remnant gastrectomy with reconstruction. Pathology confirmed T2N1 pancreatic adenocarcinoma, 1/29 lymph nodes positive and diffuse IPMN. She completed adjuvant chemotherapy. IPMNs have malignant potential and upfront surgical resection should be considered without biopsy in the appropriate clinical setting.

Association of autoimmune pancreatitis and intraductal papillary mucinous neoplasm. A retrospective analysis from a tertiary care referral center.

BACKGROUND: Autoimmune Pancreatitis (AIP) is a rare chronic inflammatory disease affecting the pancreas. Chronic pancreatic inflammation represents a risk factor for pre-neoplastic conditions such as Intraductal Papillary Mucinous Neoplasia (IPMN). Due to the rarity of AIP, the incidence, and clinical features of IPMN occurring in AIP patients remains unknown. AIMS: In the present study we aimed to explore the relationship between AIP and IPMN and to characterize the clinical features and outcomes of IPMN occurring in the context of AIP. METHODS: We retrospectively (2008-2020) analyzed the clinical and radiological records of a large single center cohort of patients with AIP and investigated the prevalence of IPMN. We then compared the clinical, laboratory and radiological characteristics of patients with IPMN and AIP with a cohort of patients with isolated IPMN. RESULTS: Five hundred and nineteen patients were included in this retrospective study. Sixteen patients had concomitant IPMN and AIP(3%); 61 patients had isolated AIP (12%); 442 patients had isolated IPMN (85%). The prevalence of IPMN in patients with AIP was higher than that observed in the general population (21%vs8-10%). Worrisome Features and High-Risk Stigmata were more frequently observed in IPMN occurring together with AIP compared to isolated IPMN(p < 0.05). Based on radiological features IPMN in the context of AIP was more frequently of main-duct type compared to isolated IPMN(p < 0.05). CONCLUSION: Our data suggest that AIP represents a chronic inflammatory condition that might favor IPMN development with high-risk features. Prolonged surveillance of these patients and longitudinal studies are required to further test the association with AIP and malignant and pre-malignant conditions.

Systematic review on surveillance for non-resected branch-duct intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND: The management of branch-duct type intraductal papillary mucinous neoplasms (BD-IPMN) varies in existing guidelines. This study investigated the optimal surveillance protocol and safe discontinuation of surveillance considering natural history in non-resected IPMN, by systematically reviewing the published literature. METHODS: This review was guided by PRISMA. Research questions were framed in PICO format "CQ1-1: Is size criteria helpful to determine surveillance period? CQ1-2: How often should surveillance be carried out? CQ1-3: When should surveillance be discontinued? CQ1-4: Is nomogram predicting malignancy useful during surveillance?". PubMed was searched from January-April 2022. RESULTS: The search generated 2373 citations. After screening, 83 articles were included. Among them, 33 studies were identified for CQ1-1, 19 for CQ1-2, 26 for CQ1-3 and 12 for CQ1-4. Cysts <1.5 or 2 cm without worrisome features (WF) were described as more indolent, and most studies advised an initial period of surveillance. The median growth rate of cysts <2 cm ranged from 0.23 to 0.6 mm/year. Patients with cysts <2 cm showing no morphological changes and no WF after 5-years of surveillance have minimal malignancy risk of 0-2%. Two nomograms created with over 1000 patients had AUCs of around 0.8 and appear to be feasible in a real-world practice. CONCLUSIONS: For patients with suspected BD-IPMN <2 cm and no other WF, less frequent surveillance is recommended. Surveillance may be discontinued for cysts that remain stable during 5-year surveillance, with consideration of patient condition and life expectancy. With this updated surveillance strategy, patients with non-worrisome BD-IPMN should expect more streamlined management and decreased healthcare utilization.

Identification of spatially-resolved markers of malignant transformation in Intraductal Papillary Mucinous Neoplasms.

The existing Intraductal Papillary Mucinous Neoplasm (IPMN) risk stratification relies on clinical and histological factors, resulting in inaccuracies and leading to suboptimal treatment. This is due to the lack of appropriate molecular markers that can guide patients toward the best therapeutic options. Here, we assess and confirm subtype-specific markers for IPMN across two independent cohorts of patients using two Spatial Transcriptomics (ST) technologies. Specifically, we identify HOXB3 and ZNF117 as markers for Low-Grade Dysplasia, SPDEF and gastric neck cell markers in borderline cases, and NKX6-2 and gastric isthmus cell markers in High-Grade-Dysplasia Gastric IPMN, highlighting the role of TNFα and MYC activation in IPMN progression and the role of NKX6-2 in the specific Gastric IPMN progression. In conclusion, our work provides a step forward in understanding the gene expression landscapes of IPMN and the critical transcriptional networks related to PDAC progression.

A Comparison of Spatial and Phenotypic Immune Profiles of Pancreatic Ductal Adenocarcinoma and Its Precursor Lesions.

Pancreatic ductal adenocarcinoma (PDAC) is a devastating disease with a 5-year survival rate of 12.5%. PDAC predominantly arises from non-cystic pancreatic intraepithelial neoplasia (PanIN) and cystic intraductal papillary mucinous neoplasm (IPMN). We used multiplex immunofluorescence and computational imaging technology to characterize, map, and compare the immune microenvironments (IMEs) of PDAC and its precursor lesions. We demonstrate that the IME of IPMN was abundantly infiltrated with CD8+ T cells and PD-L1-positive antigen-presenting cells (APCs), whereas the IME of PanIN contained fewer CD8+ T cells and fewer PD-L1-positive APCs but elevated numbers of immunosuppressive regulatory T cells (Tregs). Thus, immunosuppression in IPMN and PanIN seems to be mediated by different mechanisms. While immunosuppression in IPMN is facilitated by PD-L1 expression on APCs, Tregs seem to play a key role in PanIN. Our findings suggest potential immunotherapeutic interventions for high-risk precursor lesions, namely, targeting PD-1/PD-L1 in IPMN and CTLA-4-positive Tregs in PanIN to restore immunosurveillance and prevent progression to cancer. Tregs accumulate with malignant transformation, as observed in PDAC, and to a lesser extent in IPMN-associated PDAC (IAPA). High numbers of Tregs in the microenvironment of PDAC went along with a markedly decreased interaction between CD8+ T cells and cancerous epithelial cells (ECs), highlighting the importance of Tregs as key players in immunosuppression in PDAC. We found evidence that a defect in antigen presentation, further aggravated by PD-L1 expression on APC, may contribute to immunosuppression in IAPA, suggesting a role for PD-L1/PD-1 immune checkpoint inhibitors in the treatment of IAPA.

Absence of a pancreatic microbiome in intraductal papillary mucinous neoplasm.

OBJECTIVE: This study aims to validate the existence of a microbiome within intraductal papillary mucinous neoplasm (IPMN) that can be differentiated from the taxonomically diverse DNA background of next-generation sequencing procedures. DESIGN: We generated 16S rRNA amplicon sequencing data to analyse 338 cyst fluid samples from 190 patients and 19 negative controls, the latter collected directly from sterile syringes in the operating room. A subset of samples (n=20) and blanks (n=5) were spiked with known concentrations of bacterial cells alien to the human microbiome to infer absolute abundances of microbial traces. All cyst fluid samples were obtained intraoperatively and included IPMNs with various degrees of dysplasia as well as other cystic neoplasms. Follow-up culturing experiments were conducted to assess bacterial growth for microbiologically significant signals. RESULTS: Microbiome signatures of cyst fluid samples were inseparable from those of negative controls, with no difference in taxonomic diversity, and microbial community composition. In a patient subgroup that had recently undergone invasive procedures, a bacterial signal was evident. This outlier signal was not characterised by higher taxonomic diversity but by an increased dominance index of a gut-associated microbe, leading to lower taxonomic evenness compared with the background signal. CONCLUSION: The 'microbiome' of IPMNs and other pancreatic cystic neoplasms does not deviate from the background signature of negative controls, supporting the concept of a sterile environment. Outlier signals may appear in a small fraction of patients following recent invasive endoscopic procedures. No associations between microbial patterns and clinical or cyst parameters were apparent.

Gastrointestinal cancer precursor risk and mortality in pancreatic intraductal papillary mucinous neoplasms: a nationwide cohort study.

BACKGROUND AND AIMS: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a precursor of pancreatic cancer. While earlier research has shown a high prevalence of synchronous/metachronous extrapancreatic tumors in IPMN patients, these studies have often been small with retrospective data collection. The aim of the study was to examine absolute and relative risks of non-pancreatic gastrointestinal (GI) cancer precursors and mortality in histologically confirmed IPMN. METHODS: Through the nationwide ESPRESSO histopathology cohort, we retrieved data on IPMN between 1965 and 2016. Each index case was matched to ≤5 general population controls. Through Cox regression, we estimated hazard ratios (HRs) for future GI cancer precursors and death. RESULTS: A total of 117 patients with IPMN and 539 age- and sex-matched controls were included. Over a median of 2.1 years of follow up, we confirmed two (1.7%) incident GI cancer precursors in IPMN vs. four (0.7%) in controls, corresponding to an HR of 1.89 (95%CI = 0.34-10.55). By contrast, IPMN patients were at increased risk of death (HR 3.61 (95%CI = 1.79-7.27)). The most common cause of death in IPMN was pancreatic cancer (n = 14; 45.2% of all deaths). CONCLUSIONS: We found no association between IPMN and other GI cancer precursors. This argues against comprehensive routine surveillance for other GI cancer precursors in IPMN patients. Mortality was increased in IPMN with pancreatic cancer being the most common cause of death, indicating the need for lifelong follow up in all resected and non-resected patients with IPMN. However, results should be confirmed in larger cohorts.

Utilization of texture features of volumetric ADC maps in differentiating between serous cystadenoma and intraductal papillary neoplasms.

INTRODUCTION: The rising incidence of incidental detection of pancreatic cystic neoplasms has compelled radiologists to determine new diagnostic methods for the differentiation of various kinds of lesions. We aim to demonstrate the utility of texture features extracted from ADC maps in differentiating intraductal papillary mucinous neoplasms (IPMN) from serous cystadenomas (SCA). METHODS: This retrospective study was performed on 136 patients (IPMN = 87, SCA = 49) split into testing and training datasets. A total of 851 radiomics features were extracted from volumetric contours drawn by an expert radiologist on ADC maps of the lesions. LASSO regression analysis was used to determine the most predictive set of features and a radiomics score was developed based on their respective coefficients. A hyper-optimized support vector machine was then utilized to classify the lesions based on their radiomics score. RESULTS: A total of four Wavelet features (LHL/GLCM/LCM2, HLL/GLCM/LCM2, /LLL/First Order/90percent, /LLL/GLCM/MCC) were selected from all of the features to be included in our classifier. The classifier was optimized by altering hyperparameters and the trained model was applied to the validation dataset. The model achieved a sensitivity of 92.8, specificity of 90%, and an AUC of 0.97 in the training data set, and a sensitivity of 83.3%, specificity of 66.7%, and AUC of 0.90 in the testing dataset. CONCLUSION: A support vector machine model trained and validated on volumetric texture features extracted from ADC maps showed the possible beneficence of these features in differentiating IPMNs from SCAs. These results are in line with previous regarding the role of ADC maps in classifying cystic lesions and offers new evidence regarding the role of texture features in differentiation of potentially neoplastic and benign lesions.

Discrimination of pancreato-biliary cancer and pancreatitis patients by non-invasive liquid biopsy.

BACKGROUND: Current diagnostics for the detection of pancreato-biliary cancers (PBCs) need to be optimized. We therefore propose that methylated cell-free DNA (cfDNA) derived from non-invasive liquid biopsies serves as a novel biomarker with the ability to discriminate pancreato-biliary cancers from non-cancer pancreatitis patients. METHODS: Differentially methylated regions (DMRs) from plasma cfDNA between PBCs, pancreatitis and clinical control samples conditions were identified by next-generation sequencing after enrichment using methyl-binding domains and database searches to generate a discriminatory panel for a hybridization and capture assay with subsequent targeted high throughput sequencing. RESULTS: The hybridization and capture panel, covering around 74 kb in total, was applied to sequence a cohort of 25 PBCs, 25 pancreatitis patients, 25 clinical controls, and seven cases of Intraductal Papillary Mucinous Neoplasia (IPMN). An unbiased machine learning approach identified the 50 most discriminatory methylation markers for the discrimination of PBC from pancreatitis and controls resulting in an AUROC of 0.85 and 0.88 for a training (n = 45) and a validation (n = 37) data set, respectively. The panel was also able to distinguish high grade from low grade IPMN samples. CONCLUSIONS: We present a proof of concept for a methylation biomarker panel with better performance and improved discriminatory power than the current clinical marker CA19-9 for the discrimination of pancreato-biliary cancers from non-cancerous pancreatitis patients and clinical controls. This workflow might be used in future diagnostics for the detection of precancerous lesions, e.g. the identification of high grade IPMNs vs. low grade IPMNs.

Outcomes of Neoadjuvant Chemotherapy for Invasive Intraductal Papillary Mucinous Neoplasm Compared with de Novo Pancreatic Adenocarcinoma.

BACKGROUND: The management of invasive intraductal papillary mucinous cystic neoplasm (I-IPMN) does not differ from de novo pancreatic ductal adenocarcinoma (PDAC); however, I-IPMNs are debated to have better prognosis. Despite being managed similarly to PDAC, no data are available on the response of I-IPMN to neoadjuvant chemotherapy. METHODS: All patients undergoing pancreatic resection for a pancreatic adenocarcinoma from 2011 to 2022 were included. The PDAC and I-IPMN cohorts were compared to evaluate response to neoadjuvant therapy (NAT) and overall survival (OS). RESULTS: This study included 1052 PDAC patients and 105 I-IPMN patients. NAT was performed in 25% of I-IPMN patients and 65% of PDAC patients. I-IPMN showed a similar pattern of pathological response to NAT compared with PDAC (p = 0.231). Furthermore, positron emission tomography (PET) response (71% vs. 61%; p = 0.447), CA19.9 normalization (85% vs. 76%, p = 0.290), and radiological response (32% vs. 37%, p = 0.628) were comparable between I-IPMN and PDAC. A significantly higher OS and disease-free survival (DFS) of I-IPMN was denoted by Kaplan-Meier analysis, with a p-value of < 0.001 in both plots. In a multivariate analysis, I-IPMN histology was independently associated with lower risk of recurrence and death. CONCLUSIONS: I-IPMN patients have a longer OS and DFS after surgical treatment when compared with PDAC patients. The more favorable oncologic outcome of I-IPMNs does not seem to be related to early detection, as I-IPMN histological subclass is independently associated with a lower risk of disease recurrence. Moreover, neoadjuvant effect on I-IPMN was non-inferior to PDAC in terms of pathological, CA19.9, PET, and radiological response and thus can be considered in selected patients.

Optimal age to discontinue long-term surveillance of intraductal papillary mucinous neoplasms: comparative cost-effectiveness of surveillance by age.

OBJECTIVE: Current guidelines recommend long-term image-based surveillance for patients with low-risk intraductal papillary mucinous neoplasms (IPMNs). This simulation study aimed to examine the comparative cost-effectiveness of continued versus discontinued surveillance at different ages and define the optimal age to stop surveillance. DESIGN: We constructed a Markov model with a lifetime horizon to simulate the clinical course of patients with IPMNs receiving imaging-based surveillance. We calculated incremental cost-effectiveness ratios (ICERs) for continued versus discontinued surveillance at different ages to stop surveillance, stratified by sex and IPMN types (branch-duct vs mixed-type). We determined the optimal age to stop surveillance as the lowest age at which the ICER exceeded the willingness-to-pay threshold of US$100 000 per quality-adjusted life year. To estimate model parameters, we used a clinical cohort of 3000 patients with IPMNs and a national database including 40 166 patients with pancreatic cancer receiving pancreatectomy as well as published data. RESULTS: In male patients, the optimal age to stop surveillance was 76-78 years irrespective of the IPMN types, compared with 70, 73, 81, and 84 years for female patients with branch-duct IPMNs <20 mm, =20-29 mm, ≥30 mm and mixed-type IPMNs, respectively. The suggested ages became younger according to an increasing level of comorbidities. In cases with high comorbidity burden, the ICERs were above the willingness-to-pay threshold irrespective of sex and the size of branch-duct IPMNs. CONCLUSIONS: The cost-effectiveness of long-term IPMN surveillance depended on sex, IPMN types, and comorbidity levels, suggesting the potential to personalise patient management from the health economic perspective.

Optimal Surveillance Interval of Branch Duct Intraductal Papillary Mucinous Neoplasm of the Pancreas.

Importance: Despite the increasing prevalence of intraductal papillary mucinous neoplasm (IPMN), data on the growth and malignant conversion rates based on long-term surveillance cohorts are limited. Many international guidelines recommend surveillance for benign lesions, but the optimal interval and duration are unclear. Objective: To determine the optimal surveillance protocol for IPMN and propose which patients may be exempted from surveillance. Design, Setting, and Participants: This large-scale, international cohort study examined data of 3825 patients with IPMN treated at 5 tertiary pancreatic centers. Included were patients with branch duct (BD) IPMN who underwent surveillance or surgery between January 1, 1988, and December 31, 2020. After a thorough review, 3656 patients were included in the analytic sample. Changes in cyst size, worrisome features or high-risk stigmata, and malignant conversion rates were assessed. Patients who underwent surveillance over 5 years were compared to suggest discontinuation of surveillance protocol. Clinical data collection began in January 1, 2021, and the mean (SD) follow-up duration was 84 (47.7) months. The data analysis was performed from May 2, 2022, through September 14, 2022. Exposure: The patients with BD-IPMN were followed up based on International Association of Pancreatology guidelines. Patients with suspicious malignant neoplasms during surveillance underwent surgical resection. Main Outcome and Measures: The main outcome of this study was the optimal follow-up interval and duration of BD-IPMN surveillance. The association among cyst size, growth rate, and progression was examined using descriptive statistics. Results: Of the 3656 patients with BD-IPMN in the analytic sample (1973 [54.0%] female; mean [SD] age, 63.7 [10.2] years), 172 (4.7%) were confirmed to have malignant lesions through surgery. Considering cyst growth, the time to develop worrisome features, and malignant conversion, a 1.5-, 1-, and 0.5-year surveillance interval could be optimal for cysts smaller than 20 mm, 20 to 30 mm, and 30 mm, respectively, after initial short-term (6-month) follow-up. Patients with cysts smaller than 20 mm, no worrisome features, and no growth during 5-year surveillance did not show malignant conversion after 5 years of follow-up and had time to progression of greater than 10 years. Conclusions: These findings suggest that BD-IPMN surveillance may depend on the size of the cyst and morphologic changes at the initial 6-month follow-up. For patients with small cysts (ie, <20 mm) with no morphologic changes during the initial 5-year surveillance period, surveillance may be discontinued for those unfit for surgery or who have a limited life expectancy of 10 years or less.

Outcomes after distal pancreatectomy with or without splenectomy for intraductal papillary mucinous neoplasm: international multicentre cohort study.

BACKGROUND: International guidelines on intraductal papillary mucinous neoplasm (IPMN) recommend a formal oncological resection including splenectomy when distal pancreatectomy is indicated. This study aimed to compare oncological and surgical outcomes after distal pancreatectomy with or without splenectomy in patients with presumed IPMN. METHODS: An international, retrospective cohort study was undertaken in 14 high-volume centres from 7 countries including consecutive patients after distal pancreatectomy for IPMN (2005-2019). Patients were divided into spleen-preserving distal pancreatectomy (SPDP) and distal pancreatectomy with splenectomy (DPS). The primary outcome was lymph node metastasis (LNM). Secondary outcomes were overall survival, duration of operation, blood loss, and secondary splenectomy. RESULTS: Overall, 700 patients were included after distal pancreatectomy for IPMN; 123 underwent SPDP (17.6%) and 577 DPS (82.4%). The rate of malignancy was 29.6% (137 patients) and the overall rate of LNM 6.7% (47 patients). Patients with preoperative suspicion of malignancy had a LNM rate of 17.2% (23 of 134) versus 4.3% (23 of 539) among patients without suspected malignancy (P < 0.001). Overall, SPDP was associated with a shorter operating time (median 180 versus 226 min; P = 0.001), less blood loss (100 versus 336 ml; P = 0.001), and shorter hospital stay (5 versus 8 days; P < 0.001). No significant difference in overall survival was observed between SPDP and DPS for IPMN after correction for prognostic factors (HR 0.50, 95% c.i. 0.22 to 1.18; P = 0.504). CONCLUSION: This international cohort study found LNM in 6.7% of patients undergoing distal pancreatectomy for IPMN. In patients without preoperative suspicion of malignancy, SPDP seemed oncologically safe and was associated with improved short-term outcomes compared with DPS.