Risk factors associated with the postoperative recurrence of intraductal papillary mucinous neoplasms of the pancreas

Recurrence following Resection of Intraductal Papillary Mucinous Neoplasms: A Systematic Review to Guide Surveillance

Patients who undergo resection for non-invasive IPMN are at risk for long-term recurrence. Further evidence is needed to identify evidence-based surveillance strategies based on the risk of recurrence. We performed a systematic review of the current literature regarding recurrence patterns following resection of non-invasive IPMN to summarize evidence-based recommendations for surveillance. Among the 61 studies reviewed, a total of 8779 patients underwent resection for non-invasive IPMN. The pooled overall median follow-up time was 49.5 months (IQR: 38.5-57.7) and ranged between 14.1 months and 114 months. The overall median recurrence rate for patients with resected non-invasive IPMN was 8.8% (IQR: 5.0, 15.6) and ranged from 0% to 27.6%. Among the 33 studies reporting the time to recurrence, the overall median time to recurrence was 24 months (IQR: 17, 46). Existing literature on recurrence rates and post-resection surveillance strategies for patients with resected non-invasive IPMN varies greatly. Patients with resected non-invasive IPMN appear to be at risk for long-term recurrence and should undergo routine surveillance.

Number of Worrisome Features and Risk of Malignancy in Intraductal Papillary Mucinous Neoplasm

BACKGROUND

The 2017 revised International Association of Pancreatology guidelines for management of intraductal papillary mucinous neoplasm (IPMN) describe worrisome features (WF) and high-risk stigmata (HRS), recommending resection in the latter and further work-up and close surveillance for patients with WF. The effect of multiple WF on the likelihood of malignancy has not been evaluated.

STUDY DESIGN

Eight hundred ten patients who underwent pancreatic resection for IPMN in 2 tertiary referral centers were identified from prospective institutional databases. Patients were retrospectively categorized into subgroups according to the number of WF or HRS and presence of malignancy, defined as high-grade dysplasia (HGD) or invasive cancer on final pathology.

RESULTS

Three hundred seventy-nine (47%) patients had HRS, 370 (46%) had 1 or more WF, and 61 patients (7%) had neither. Malignancy was present in 70% (n = 267) of patients with HRS and in 30% (n = 127) of those with WF. Only 3 of 61 patients without WF/HRS had malignancy, and all only in the form of HGD. The risk of malignancy increased in a stepwise fashion with the number of WF, to 22%, 34%, and 59% with 1, 2, and 3 WF, respectively (p = 0.001), and reached 100% in patients with 4 or more WF. Although the relative risks differed for particular WF, the areas under the curve were not statistically different.

CONCLUSION

We confirm that presence of HRS in IPMN is associated with a very high likelihood of malignancy. The presence of a single WF has a malignancy risk of 22%, and additional WF increase this risk significantly. When 3 or more WF are present, the risk is similar to that of HRS.

State-of-the-art surgical treatment of IPMNs

Background

A “pandemic” of incidentally discovered pancreatic cyst neoplasms (PCNs) is ongoing. Among PCNs, intraductal papillary mucinous cystic neoplasms (IPMNs) are the most common and with their complex biology could represent a precursor lesion of pancreatic cancer. Although multiple guidelines exist to guide their treatment, there are still many “gray areas” on indications for surgery for IPMNs.

Methods

The current indications for surgery of IPMNs were reappraised, considering potential discrepancies between available evidence and guidelines policies. The practice at a high-volume center for the diagnosis and treatment of PCN was presented and discussed.

Results

Most IPMNs do not and will never require surgery, as they won’t progress to malignancy. The current literature is solid in identifying high-grade dysplasia (HGD) as the right and timely target for IPMN resection, but how to precisely assess its presence remains controversial and guidelines lack of accuracy in this regard. Multiple tumorigenic pathways of progression of IPMNs exist, and their knowledge will likely lead to more accurate tests for malignancy prediction in the future.

Conclusions

The surgical management of IPMNs still is a matter of debate. Indication for resection should be considered only in highly selected cases with the ideal target of HGD. Clinicians should critically interpret the guidelines’ indications, refer to a multidisciplinary team discussion, and always consider the outcome of an adequate counselling with the patient.

The Impact of Clinical and Pathological Features on Intraductal Papillary Mucinous Neoplasm Recurrence After Surgical Resection: Long-Term Follow-Up Analysis

OBJECTIVE

This study aimed to identify risk factors for recurrence after pancreatic resection for intraductal papillary mucinous neoplasm (IPMN).

SUMMARY BACKGROUND DATA

Long-term follow-up data on recurrence after surgical resection for IPMN are currently lacking. Previous studies have presented mixed results on the role of margin status in risk of recurrence after surgical resection.

METHODS

A total of 126 patients that underwent resection for noninvasive IPMN were followed for a median of 9.5 years. Dedicated pathological and radiological reviews were performed to correlate clinical and pathological features (including detailed pathological features of the parenchymal margin) with recurrence after surgical resection. In addition, in a subset of 32 patients with positive margins, we determined the relationship between the margin and original IPMN using driver gene mutations identified by next-generation sequencing.

RESULTS

Family history of pancreatic cancer and high-grade IPMN was identified as risk factors for recurrence in both uni- and multivariate analysis (adjusted hazard ratio 3.05 and 1.88, respectively). Although positive margin was not significantly associated with recurrence in our cohort, the size and grade of the dysplastic focus at the margin were significantly correlated with recurrence in margin-positive patients. Genetic analyses showed that the neoplastic epithelium at the margin was independent from the original IPMN in at least 9 of 32 cases (28%). The majority of recurrences (74%) occurred after 3 years, and a significant minority (32%) occurred after 5 years.

CONCLUSION

Sustained postoperative surveillance for all patients is indicated, particularly those with risk factors such has family history and high-grade dysplasia.

Diabetes mellitus in intraductal papillary mucinous neoplasms: A systematic review and meta-analysis

BACKGROUND

Our current knowledge of diabetes mellitus in intraductal papillary mucinous neoplasm is very limited and its prevalence and predictive value for malignant transformation are not clear. This study sought to systematically review the literature to define the prevalence of diabetes mellitus in intraductal papillary mucinous neoplasm and to evaluate the association of diabetes mellitus with the progression to high-grade dysplasia or invasive cancer.

METHODS

A PubMed/Medline systematic search was performed to identify studies reporting data on preoperative diabetes mellitus in intraductal papillary mucinous neoplasm. Articles meeting the predefined inclusion criteria were analyzed and a meta-analysis was performed. The study was preregistered (PROSPERO ID: CRD42020153581).

RESULTS

From the initially detected 827 studies, 27 studies including resected patients with histologically confirmed intraductal papillary mucinous neoplasm were included. The global prevalence of preoperative diabetes mellitus was 25% (1,112 of 4,412); whereas new-onset/worsening diabetes mellitus was reported in 6% of patients (68 of 1,202). The meta-analysis revealed that patients with pre-existing diabetes mellitus had an increased risk of harboring a main pancreatic duct involvement (risk ratio 1.43, 95% confidence interval: 1.21-1.69, P < .001), high-grade dysplasia (risk ratio 1.27, 95% confidence interval: 1.01-1.59, P = .04), and invasive cancer (risk ratio 1.61, 95% confidence interval: 1.33-1.95, P < .001).

CONCLUSION

The prevalence of diabetes mellitus in intraductal papillary mucinous neoplasm is high, and diabetic patients demonstrate an increased risk of a more aggressive disease. Therefore, diabetes mellitus should be increasingly considered in the stratification of patients with intraductal papillary mucinous neoplasm. Further investigations to determine the mechanisms behind the association with progression should be carried out.

Diagnosis and Surveillance of Incidental Pancreatic Cystic Lesions: 2017 Consensus Recommendations of the Korean Society of Abdominal Radiology

The occurrence of incidentally detected pancreatic cystic lesions (PCLs) is continuously increasing. Radiologic examinations including computed tomography and magnetic resonance imaging with magnetic resonance cholangiopancreatography have been widely used as the main diagnostic and surveillance methods for patients with incidental PCLs. Although most incidentally detected PCLs are considered benign, they have the potential to become malignant. Currently, we have several guidelines for the management of incidental PCLs. However, there is still debate over proper management, in terms of accurate diagnosis, optimal follow-up interval, and imaging tools. Because imaging studies play a crucial role in the management of incidental PCLs, the 2017 consensus recommendations of the Korean Society of Abdominal Radiology for the diagnosis and surveillance of incidental PCLs approved 11 out of 16 recommendations. Although several challenges remain in terms of optimization and standardization, these consensus recommendations might serve as useful tools to provide a more standardized approach and to optimize care of patients with incidental PCLs.

Diagnosis and management of pancreatic cystic neoplasms: current evidence and guidelines

Pancreatic cystic neoplasms (PCN) are a heterogeneous group of pancreatic cysts that include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystic neoplasms and other rare cystic lesions, all with different biological behaviours and variable risk of progression to malignancy. As more pancreatic cysts are incidentally discovered on routine cross-sectional imaging, optimal surveillance for patients with PCN is becoming an increasingly common clinical problem, highlighting the need to balance cancer prevention with the risk of (surgical) overtreatment. This Review summarizes the latest developments in the diagnosis and management of PCN, including the quality of available evidence. Also discussed are the most important differences between the PCN guidelines from the American Gastroenterological Association, the International Association of Pancreatology and the European Study Group on Cystic Tumours of the Pancreas, including diagnostic and follow-up strategies and indications for surgery. Finally, new developments in the management of patients with PCN are addressed.

Does Surgical Margin Impact Recurrence in Noninvasive Intraductal Papillary Mucinous Neoplasms?: A Multi-institutional Study

OBJECTIVE

The relevance of margin positivity on recurrence after resection of intraductal papillary mucinous neoplasms (IPMNs) is poorly defined and represents one reason controversy remains regarding optimal surveillance recommendations.

METHODS

Patients undergoing surgery for noninvasive IPMN at 8 academic medical centers from the Central Pancreas Consortium were analyzed. A positive margin was defined as presence of IPMN or pancreatic intraepithelial neoplasia.

RESULTS

Five hundred two patients underwent surgery for IPMN; 330 (66%) did not have invasive cancer on final pathology and form the study cohort. Of these, 20% harbored high grade dysplasia. A positive margin was found in 20% of cases and was associated with multifocal disease (P = 0.02). The majority of positive margins were associated with low grade dysplasia. At a median follow-up of 36 months, 34 (10.3%) patients recurred, with 6.7% developing recurrent cystic disease and 3.6% developing invasive cancer. On multivariate analysis, margin positivity was not associated with recurrence of either IPMN or invasive cancer (P > 0.05). No association between margin status and development of recurrence at the margin was found. Only 6% of recurrences developed at the resection margin and median time to recurrence was 22 months. Of note, 18% of recurrences occurred > 5 years following surgery.

CONCLUSION

Margin positivity after resection for noninvasive IPMNs is primarily due to low grade dysplasia and is not associated with developing recurrence in the remnant pancreas or at the resection margin. Long-term surveillance is required for all patients, as a significant number of recurrences developed over 5 years after the index operation.

The Dilemma of the Dilated Main Pancreatic Duct in the Distal Pancreatic Remnant After Proximal Pancreatectomy for IPMN

OBJECTIVE(S)

A dilated main pancreatic duct in the distal remnant after proximal pancreatectomy for intraductal papillary mucinous neoplasms (IPMN) poses a diagnostic dilemma. We sought to determine parameters predictive of remnant main-duct IPMN and malignancy during surveillance.

METHODS

Three hundred seventeen patients underwent proximal pancreatectomy for IPMN (Indiana University, 1991-2016). Main-duct dilation included those ≥ 5 mm or "dilated" on radiographic reports. Statistics compared groups using Student's T/Mann-Whitney U tests for continuous variables or chi-square/Fisher's exact test for categorical variables with P < 0.05 considered significant.

RESULTS

High-grade/invasive IPMN or adenocarcinoma at proximal pancreatectomy predicted malignant outcomes (100.0% malignant outcomes; P < 0.001) in remnant surveillance. Low/moderate-grade lesions revealed benign outcomes at last surveillance regardless of duct diameter. Twenty of 21 patients undergoing distal remnant reoperation had a dilated main duct. Seven had main-duct IPMN on remnant pathology; these patients had greater mean maximum main-duct diameter prior to reoperation (9.5 vs 6.2 mm, P = 0.072), but this did not reach statistical significance. Several features showed high sensitivity/specificity for remnant main-duct IPMN.

CONCLUSIONS

Remnant main-duct dilation after proximal pancreatectomy for IPMN remains a diagnostic dilemma. Several parameters show a promise in accurately diagnosing main-duct IPMN in the remnant.

Head and Body/Tail Pancreatic Carcinomas Are Not the Same Tumors

The association between pancreatic ductal adenocarcinoma (PDAC) location (head vs. Body/Tail (B/T)) and clinical outcome remains controversial. We collected clinicopathological and gene expression data from 249 resected PDAC samples from public data sets, and we compared data between 208 head and 41 B/T samples. The 2-year overall survival (OS) was better for the head than for the B/T PDACs (44 vs. 27%, p = 0.043), especially when comparing tumors with similar TNM classification (T3/4N0M0: 67% vs. 17%, p = 0.002) or from the same molecular class (squamous subtype: 31% vs. 0%, p < 0.0001). Bailey's molecular subtypes were differentially distributed within the two groups, with the immunogenic subtype being underrepresented in the "B/T" group (p = 0.005). Uni- and multivariate analyses indicated that PDAC anatomic location was an independent prognostic factor. Finally, the supervised analysis identified 334 genes differentially expressed. Genes upregulated in the "head" group suggested lymphocyte activation and pancreas exocrine functions. Genes upregulated in the "B/T" group were related to keratinocyte differentiation, in line with the enrichment for squamous phenotype. We identified a robust gene expression signature (GES) associated with B/T PDAC location, suggesting that head and B/T PDAC are different. This GES could serve as an indicator for differential therapeutic management based on PDAC location.

Cyst location and presence of high grade dysplasia or invasive cancer in intraductal papillary mucinous neoplasms of the pancreas: a seven institution study from the central pancreas consortium

BACKGROUND

Traditionally, intraductal papillary mucinous neoplasms (IPMNs) of the pancreas with "high risk stigmata" (HRS) or "worrisome features" (WF) are referred for resection. We aim to assess if IPMN location is predictive of harboring either high grade dysplasia (HGD) or invasive cancer (IC).

METHODS

Patients undergoing resection for IPMN from seven institutions between 2000 and 2015 (n = 275) were analyzed. HRS and WF were defined by the 2012 Fukuoka international consensus guidelines.

RESULTS

168 (61%) patients had head/uncinate cysts, while 107 (39%) had neck/body/tail cysts. No differences were noted between groups with regard to age, duct type, cyst size, or presence of at least one WF. Patients with cysts in the head/uncinate were more often male (55% vs. 40%), had at least one HRS (24% vs. 11%), and more often harbored HGD or IC(49% vs. 27%)[all p < 0.05]. On multivariate analysis, only cyst location in the head/uncinate remained associated with presence of HGD or IC(odds ratio 4.76, p = 0.02).

DISCUSSION

Cyst location is predictive of HGD or IC in patients with IPMNs. Head/uncinated cysts are more likely to harbor malignancy compared to those of the neck/body/tail. Additional studies are needed to confirm these findings, however, cyst location should be considered part of the decision making process for surveillance vs. resection for IPMNs.

Adjuvant radiation provides survival benefit for resected pancreatic adenocarcinomas of the tail

BACKGROUND

The appropriate adjuvant treatment for resected pancreatic cancer remains a controversy. We sought to determine the effect of adjuvant treatment on overall survival (OS) in patients with pancreatic tail adenocarcinoma.

METHODS

Retrospective review of patients with upfront surgically resected pancreatic tail cancer treated at our institution between 2000-2012 was performed to determine outcomes of patients treated with and without adjuvant radiation therapy (RT). Survival curves were calculated according to the Kaplan-Meier method. Univariate analysis (UVA) and multivariate analysis (MVA) were performed using the Cox proportional hazards model.

RESULTS

Thirty-four patients met inclusion criteria. 79% received adjuvant chemotherapy, either concurrent with RT or alone. The groups were well matched, with the only significant difference being patient sex. On both UVA and MVA there was significantly worse survival in patients with a post-op CA19-9 >90 [hazard ratio (HR) 5.55; 95% confidence interval (CI): 1.20-25.7, P=0.03] and improved survival in patients treated with adjuvant RT (HR 0.15; 95% CI: 0.04-0.58, P=0.006). The median and 2-year OS were 21.6 months and 47% for patients treated with adjuvant RT compared with 11.3 months and 21% for those treated without RT.

CONCLUSIONS

Although few in patient numbers, this data suggests integration of adjuvant RT in resected pancreatic tail adenocarcinoma may improve OS.

European evidence-based guidelines on pancreatic cystic neoplasms

Evidence-based guidelines on the management of pancreatic cystic neoplasms (PCN) are lacking. This guideline is a joint initiative of the European Study Group on Cystic Tumours of the Pancreas, United European Gastroenterology, European Pancreatic Club, European-African Hepato-Pancreato-Biliary Association, European Digestive Surgery, and the European Society of Gastrointestinal Endoscopy. It replaces the 2013 European consensus statement guidelines on PCN. European and non-European experts performed systematic reviews and used GRADE methodology to answer relevant clinical questions on nine topics (biomarkers, radiology, endoscopy, intraductal papillary mucinous neoplasm (IPMN), mucinous cystic neoplasm (MCN), serous cystic neoplasm, rare cysts, (neo)adjuvant treatment, and pathology). Recommendations include conservative management, relative and absolute indications for surgery. A conservative approach is recommended for asymptomatic MCN and IPMN measuring <40 mm without an enhancing nodule. Relative indications for surgery in IPMN include a main pancreatic duct (MPD) diameter between 5 and 9.9 mm or a cyst diameter ≥40 mm. Absolute indications for surgery in IPMN, due to the high-risk of malignant transformation, include jaundice, an enhancing mural nodule >5 mm, and MPD diameter >10 mm. Lifelong follow-up of IPMN is recommended in patients who are fit for surgery. The European evidence-based guidelines on PCN aim to improve the diagnosis and management of PCN.

Progression Patterns in the Remnant Pancreas after Resection of Non-Invasive or Micro-Invasive Intraductal Papillary Mucinous Neoplasms (IPMN)

BACKGROUND

Although IPMN are thought to represent a whole-gland disease, segmental resection remains the most frequently performed treatment. We sought to determine the rates, patterns, and predictors of IPMN progression in the pancreatic remnant following segmental resection of noninvasive or microinvasive IPMN.

METHODS

A prospectively maintained database was queried to identify all patients who underwent resection of noninvasive or microinvasive IPMN (≤ 10 mm of invasive component) between 1989 and 2015. Progression (recurrence) was defined as either the development of cancer, a new IPMN cystic lesion > 1 cm or ≥ 50% increase in the diameter of residual IPMN lesions in the remnant. Univariate and multivariate cox regression models were created to determine predictors of progression.

RESULTS

A total of 319 patients underwent resection for noninvasive and microinvasive IPMN. The median age was 68, 53% had branch-duct (BD) IPMN, and 6% had microinvasive disease. After a median follow-up of 42 months, 71 patients (22%) experienced IPMN progression. Within this group of 71 patients, 11 (16% of recurrence) developed invasive cancer in the pancreatic remnant after a median of 28 months. Twelve patients (17%) experienced progression > 5 years following initial resection. On multivariate analysis, a distal location of the initial lesion was associated with an increased risk of progression (multivariate hazards ratio = 2.43, confidence interval 1.47-4.0, p < 0.001).

CONCLUSIONS

In this study, 22% of patients had disease progression following resection of noninvasive or microinvasive IPMN; 16% of these progressions represented invasive disease. These patients represent a high-risk group and should undergo long-term radiographic surveillance.

The prognostic relevance of primary tumor location in patients undergoing resection for pancreatic ductal adenocarcinoma

Different clinical presentations and prognoses have been implied between pancreatic head and body/tail cancers. We aimed to identify the prognostic relevance of primary tumor location in patients undergoing resection for pancreatic ductal adenocarcinoma (PDAC). Thirty-two pairs of patients with strictly matched early stage (II) pancreatic head and body/tail cancers were enrolled. The molecular feature of the two subtypes of PDAC was assessed on the level of miRNA expression. Out of the 64 patients, 34 (53.1%) had tumor recurrence after radical resection during the follow-up period (2.3 ± 0.8 years). Both overall and tumor-free survival were significantly higher in the patients with pancreatic body/tail cancer compared with those with pancreatic head cancer. Patient age and tumor location were the independent prognostic factors for tumor recurrence. A remarkably lower expression of miR-501-3p and higher expression of miR-375 were found and were further verified in pancreatic body/tail cancer tissues compared with pancreatic head cancer tissues. The low expression of miR-501-3p was significantly associated with a low risk of tumor recurrence. Both, subcutaneous and orthotopic PDAC mouse models presented highly invasive tumor phenotypes upon up-regulated miR-501-3p expression. An in vitro study showed that miR-501-3p promoted the invasiveness of PDAC cells possibly via suppressing E-cadherin. In summary, at resectable early stage, pancreatic body/tail cancer presents a less malignant phenotype associated with deregulation of miR-501-3p compared with pancreatic head cancer.

Outcomes and prognostic factors of patients with stage IB and IIA pancreatic cancer according to the 8th edition American Joint Committee on Cancer criteria

AIM

To evaluate the changes in the 8^th edition American Joint Committee on Cancer (AJCC) for defining stage IB and IIA pancreatic cancer and identify their prognostic factors.

METHODS

Pancreatic cancer patients were selected from the Surveillance Epidemiology and End Results database (1973-2013). The enrolled patients were divided into IB and IIA groups based on tumor size according to the 8^th edition AJCC criteria. Clinical characteristics, including age, gender, race, tumor size, primary site, and grade were summarized. Univariate and multivariate analyses were performed to explore the prognostic factors of the IB and IIA stages of pancreatic cancer under new criteria.

RESULTS

A total of 1349 pancreatic cancer patients were included. More patients had stage IB rather than stage IIA. Stage IB tumors (54.85%) were mainly located in the head of the pancreas, while stage IIA tumors were more often located in the tail and head of the pancreas (35.21% and 31.75%, respectively). The survival time of stage IB and IIA patients had no significant difference. Univariate and multivariate analyses indicated that the prognostic factors of survival for stage IB and IIA patients were different. For stage IB patients, age and primary site were the independent prognostic factors; for stage IIA patients, age and grade were the independent prognostic factors. The risk of death was lower among patients aged ≤ 65 years than those aged > 65 years.

CONCLUSION

The prognostic factors for stage IB and IIA patients are different, but age is the independent prognostic factor for all patients. The survival time of stage IB and IIA patients has no significant difference.

Selecting optimal surgical procedures for intraductal papillary mucinous neoplasm (IPMN): An analysis based on the Surveillance, Epidemiology, and End Result registry database

INTRODUCTION

Intraductal papillary mucinous neoplasm (IPMN) is a field defect disease of pancreas that has malignant potential. Many studies have recommended surgery as the preferred treatment. We investigated whether a total pancreatectomy (TP) can improve patient prognosis compared to a pancreatoduodenectomy (PD) and the indications for each approach.

PATIENTS AND METHODS

We obtained data of 548 malignant IPMN patients who underwent either a TP or a PD from SEER database. The survival rates were analyzed using the Kaplan-Meier method and a Cox regression model. Cases were subdivided to investigate the advantages of each procedure.

RESULTS

The surgical procedures (PD and TP) did not significantly affect either cancer-specific survival (CSS) times or overall survival (OS) times in both Kaplan-Meier analysis and Cox regression (Kaplan-Meier: PCSS = 0.919, POS = 0.996; Cox: PCSS = 0.735, POS = 0.820). In the subgroup analyses, patients in stage T4 and AJCC stage III in the TP group had a longer survival time than did those in the PD group (33 months vs 14 months), but not significant (T4: PCSS = 0.124, AJCC III: PCSS = 0.102). In addition, PD had the trend to be better for poorly differentiated patients (Pos = 0.055) and older patients.

CONCLUSION

TP did not offer any significant OS and CSS benefits as compared to PD. However, for patients in stage T4 and AJCC stage III, TP may extend survival time in some degree. In older or histologically poorly differentiated patients, PD may be preferable to TP. The results are rational, but still warrant further verification due to limited sample volumes of specific subgroups.

Patterns of Recurrence After Resection of IPMN: Who, When, and How?

OBJECTIVE

To describe the patterns of recurrence after resection of intraductal papillary mucinous neoplasms (IPMN) of the pancreas.

BACKGROUND

IPMNs represent an increasing indication for pancreatic resection, but little is known about the actual incidence and the patterns of recurrence after surgical excision.

METHODS

Retrospective review of 412 resected IPMNs from 1990 to 2013 who have had near-complete follow-up.

RESULTS

Median age of the cohort was 68 years, 56% had branch duct (BD)-IPMN and 21% had invasive cancers. Nineteen patients (5%) had distinct pancreatic ductal adenocarcinoma (PDAC) and were excluded from the recurrence analysis. After a median of 58 months, 65 of 381 patients (17%) experienced recurrence of the IPMN, and 5- and 10-year disease-free survival (DFS) was 82% and 78%, respectively. Only 2 patients (0.5%) developed metachronous PDAC. In 33 patients (9%), a residual BD-IPMN was left in the pancreatic remnant, but none of these significantly grew or required reoperation. Invasive component and resection margin positive for IPMN were predictors of recurrence (P < 0.05). Invasive IPMN recurred in 45% of cases, whereas noninvasive in only 9% and later (P < 0.001), but patterns depended on IPMN subtypes. Only 9 patients required reoperation for recurrence, with good long-term outcome particularly for oncocytic IPMNs.

CONCLUSIONS

Recurrence of noninvasive BD-IPMN is infrequent and surveillance may be avoided in selected cases. In invasive IPMN recurrence depends on N status, pancreatic margin, and invasive type.

Risk factors for postoperative recurrence of intraductal papillary mucinous neoplasms of the pancreas based on a long-term follow-up study: proposals for follow-up strategies

BACKGROUND

The aim of this study was to examine the associations between postoperative clinicopathological features of intraductal papillary mucinous neoplasm (IPMN) and recurrence over a long follow-up period.

METHODS

We retrospectively assessed 153 IPMN patients who underwent resection.

RESULTS

The resected tumors showed low/intermediate-grade dysplasia (LGD/IGD), high-grade dysplasia (HGD), T1a (stromal invasion ≤5 mm), and invasive intraductal papillary mucinous carcinoma (IPMC), in 54.9%, 22.2%, 4.6%, and 18.3% of patients, respectively. The median follow-up period after surgery was 46.4 (6.0-216.3) months, with an overall recurrence rate of 17.0%; the recurrence rates by histological type were 6.0%, 5.9%, 42.9%, and 57.1% for LGD/IGD, HGD, T1a, and invasive IPMC, respectively. Multivariate analysis revealed that recurrences related with tumor location, mural nodule size, presence of invasive cancer, lymph node metastasis, IPMN in the remnant pancreas, and main pancreatic duct dilatation after surgery. Recurrence occurred within the remnant pancreas in all LGD-T1a patients and as extrapancreatic metastasis in all patients with invasive IPMC. Of the total recurrences, 15.4% occurred over 5 years postoperatively.

CONCLUSIONS

The postoperative follow-up protocol for patients with LGD-T1a should be similar to non-resected IPMN, and that for invasive IPMC should be the same as for pancreatic ductal adenocarcinoma patients.

Long-term prospective cohort study of patients undergoing pancreatectomy for intraductal papillary mucinous neoplasm of the pancreas: implications for postoperative surveillance

OBJECTIVE

To evaluate long-term follow-up results after surgical treatment of intraductal papillary mucinous neoplasm (IPMN) to optimize postoperative surveillance strategies.

BACKGROUND

Little is known about the postoperative natural history of IPMN, especially about long-term follow-up results in patients with benign or noninvasive IPMN.

METHODS

Long-term follow-up was undertaken in a prospective cohort of 403 consecutive patients who underwent surgical treatment of IPMN at Seoul National University Hospital. Of these, 37 patients with ductal adenocarcinoma arising in IPMN were excluded from the analysis.

RESULTS

Of the 366 patients, 82 had low-grade dysplasia, 171 had intermediate-grade dysplasia, 45 had high-grade dysplasia, and 68 had IPMN with associated invasive carcinoma. During a median follow-up of 44.4 months, the overall recurrence rate was 10.7%. Pathologic grade of dysplasia was associated with recurrence rate (P < 0.001). IPMNs involving main duct had higher rate of recurrence (P = 0.021). Of the 298 patients with benign or noninvasive IPMN, 16 (5.4%) had recurrences including distant metastasis. Multivariate analysis revealed that the degree of dysplasia was the most important predictor of recurrence (P < 0.001). The overall 5-year disease-free survival rate was 78.9% and was significantly lower in patients with high-grade dysplasia than in those with low- or intermediate-grade dysplasia (P = 0.045).

CONCLUSIONS

Pancreatic IPMNs recur in 10.7% of patients. Recurrence is correlated with the degree of dysplasia, and 5.4% of patients with benign or noninvasive IPMN have recurrences including distant metastasis. Thorough postoperative surveillance is needed not only for patients with invasive IPMN but also for those with benign or noninvasive IPMN, especially for patients with high-grade dysplasia.

Treatment strategy for main duct intraductal papillary mucinous neoplasms of the pancreas based on the assessment of recurrence in the remnant pancreas after resection: a retrospective review

OBJECTIVES

To clarify the recurrence pattern after resection of main duct intraductal papillary mucinous neoplasms (MD-IPMNs) using molecular analyses and determine the most adequate treatment strategy.

BACKGROUND

The most appropriate resection line for MD-IPMNs remains an unresolved issue.

METHODS

Medical records of 56 patients with pancreatectomy were retrospectively reviewed. Histological subtypes and Kras/GNAS mutations were assessed in patients with recurrence in the remnant pancreas.

RESULTS

Forty-nine patients underwent partial pancreatectomy and 7 underwent total pancreatectomy. Thirty-six patients (64%) had malignant MD-IPMNs. Recurrence was observed in 7 of 49 patients (14%), including 6 with malignant IPMNs and 1 with pancreatic ductal adenocarcinoma, all of whom underwent remnant pancreatectomy. The cumulative disease-specific survival rate of patients with pancreatic recurrence was greater than that of patients with extrapancreatic recurrence (P < 0.001). Although the pancreatic margin status at the initial operation did not affect the pancreatic recurrence rate, all 4 recurrent IPMNs examined had histological subtypes and Kras/GNAS mutations identical to those of the initial lesions. Four patients experienced recurrence in the remnant pancreas or systemic recurrence after resection of high-grade dysplasia of MD-IPMN. Three of the 56 patients had concomitant pancreatic ductal adenocarcinomas and MD-IPMNs.

CONCLUSIONS

One-step total pancreatectomy can be avoided, and remnant total pancreatectomy would lead to favorable outcomes even in patients with pancreatic recurrence, some cases of which seem to involve residual lesions. Postoperative surveillance of high-grade dysplasia should be performed as if malignant, and close attention should be paid to the occurrence of concomitant pancreatic ductal adenocarcinomas in patients with MD-IPMNs.

The diversity between pancreatic head and body/tail cancers: clinical parameters and in vitro models

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) can be divided into head, body and tail cancers according to the anatomy. Distinctions in tissue composition, vascularization and innervations have been clearly identified between the head and body/tail of the pancreas both in embryological development and in histopathology. To understand the postulated genotype difference, we present comprehensive information on two PDAC cell lines as typical representatives originating from pancreatic head and body/tail cancers, respectively.

DATA SOURCE

In the present review, we compare the difference between pancreatic head and body/tail cancers regarding clinical parameters and introducing an in vitro model.

RESULTS

Increasing evidence has shown that tumors at different locations (head vs body/tail) display different clinical presentation (e.g. incidence, symptom), treatment efficiency (e.g. surgery, chemotherapy) and thus patient prognosis. However, the genetic or molecular diversity (e.g. mutations, microRNA) between the two subtypes of PDAC has not been elucidated so far. They present different chemo- and/or radio-resistance, extracellular matrix adhesion and invasiveness, as well as genetic profiles.

CONCLUSION

Genetic and tumor biological diversity exists in PDAC according to the tumor localization.

Is it necessary to follow patients after resection of a benign pancreatic intraductal papillary mucinous neoplasm?

BACKGROUND

Little is known about the risk of subsequently developing a new or progressive intraductal papillary mucinous neoplasm (IPMN) after partial pancreatic resection of a noninvasive IPMN.

STUDY DESIGN

One hundred thirty patients with more than 1 year of follow-up after resection were included in this analysis.

RESULTS

At a median follow-up of 38 months, 22 (17%) developed imaging evidence of a new or progressive IPMN. Eleven (8%) underwent completion resection. Three of the 11 patients had invasive adenocarcinoma. Two other patients developed metastatic pancreatic adenocarcinoma and did not undergo resection. All 5 patients (4%) with cancer had negative margins at initial operation. Sixteen of 100 patients (16%) with negative margins for IPMN at the initial operation developed a new IPMN vs 6 of 30 patients (20%) with margins positive for IPMN (p = ns). Five of 22 patients (23%) with a new IPMN had a family history of pancreatic cancer, while 8 of 108 patients (7%) without a new IPMN had a family history (p < 0.05). Overall, the chances of developing a new IPMN at 1, 5, and 10 years after the initial surgery were 4%, 25%, and 62%, respectively, and of requiring surgery were 1.6%, 14%, and 18%, respectively. The estimated chances of developing invasive pancreatic cancer were 0%, 7%, and 38% at 1, 5, and 10 years, respectively.

CONCLUSIONS

Patients who have undergone resection for noninvasive IPMN require indefinite close surveillance because of the risks of developing a new IPMN, of requiring surgery, and of developing cancer. A family history of pancreatic cancer, but not margin status or degree of dysplasia, is associated with a risk of development of a new or progressive IPMN.

Intraductal tubulopapillary neoplasm of the pancreas with somatic BRAF mutation

Intraductal tubulopapillary neoplasm (ITPN) is a rare pancreatic tumor belonging to a newly recognized entity that is coined in the 2010 WHO classification. We present a case of ITPN-associated microinvasive adenocarcinoma that developed in an asymptomatic 78-year-old patient. The tumor demonstrated all the clinical, radiological, and pathological characteristics of ITPN, but it differs from other reported cases of ITPN in molecular analysis, which revealed a somatic mutation in BRAF (c.1799T>A; p.V600E) but no mutation in PIK3CA. Post-operative recurrence was discovered 34 months after tumor resection with negative margins and a 6-month course of adjuvant chemotherapy. To the best of our knowledge, this is the first case of ITPN with BRAF mutation. This case suggests that an activation of RAS-mitogen-activated protein kinase signaling pathway may play a role in development of some of ITPNs. A possible mechanism of tumor recurrence in ITPN is also discussed. Further case series with molecular study are awaited to delineate the clinicopathological and molecular characteristics of ITPN.

Imaging IPMN: take home messages and news

IPMN is a frequent disease involving pancreatic duct. This disease could be malignant (parenchymal invasive adenocarcinoma), particularly if the main pancreatic duct is involved (this involvement is considered present if > 6 mm), if this enlargement reaches 10 mm or more, and if the pathological phenotype is biliopancreatic or intestinal (malignancy is less frequent if gastric one). Invasiveness is suspected if hypodense parenchymal lesion is present, particularly near a cystical lesion or MPD, a mural nodule of the wall, or if MPD wall has got a contrast uptake. Mural nodules inside cystic branch duct are associated with in situ grade 3 malignancies. MPD IPMN must be resected to prevent malignancy. The follow-up of isolated branch duct cysts relies upon MDCT and MRI, every two years if lesion is less than 1cm. Every one year if bigger, particularly if more than to 3 cm.

Non-pancreatic cancer tumors in the pancreatic region

Most of tumors found in the pancreas are adenocarcinoma of the pancreas. A small number of tumors in the pancreas, such as islet cell tumors or neuroendocrine tumors, papillary cystic neoplasms, lymphoma, acinar cell tumors, metastatic tumors to the pancreas often, have a far better prognosis, and the majority of these tumors are non-malignant or benign. The author reviewed the recent literatures, and summarized where the tumor comes originally in the pancreas, what is the type of the tumor, and how to treat the tumor.