Surgical outcomes of noninvasive and minimally invasive 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.

Pancreatic Cyst Size Measurement on Magnetic Resonance Imaging Compared to Pathology

BACKGROUND

While multiple cyst features are evaluated for stratifying pancreatic intraductal papillary mucinous neoplasms (IPMN), cyst size is an important factor that can influence treatment strategies. When magnetic resonance imaging (MRI) is used to evaluate IPMNs, no universally accepted sequence provides optimal size measurements. T2-weighted coronal/axial have been suggested as primary measurement sequences; however, it remains unknown how well these and maximum all-sequence diameter measurements correlate with pathology size. This study aims to compare agreement and bias between IPMN long-axis measurements on seven commonly obtained MRI sequences with pathologic size measurements.

METHODS

This retrospective cohort included surgically resected IPMN cases with preoperative MRI exams. Long-axis diameter tumor measurements and the presence of worrisome features and/orhigh-risk stigmata were noted on all seven MRI sequences. MRI size and pathology agreement and MRI inter-observer agreement involved concordance correlation coefficient (CCC) and intraclass correlation coefficient (ICC), respectively. The presence of worrisome features and high-risk stigmata were compared to the tumor grade using kappa analysis. The Bland-Altman analysis assessed the systematic bias between MRI-size and pathology.

RESULTS

In 52 patients (age 68 ± 13 years, 22 males), MRI sequences produced mean long-axis tumor measurements from 2.45-2.65 cm. The maximum MRI lesion size had a strong agreement with pathology (CCC = 0.82 (95% CI: 0.71-0.89)). The maximum IPMN size was typically observed on the axial T1 arterial post-contrast and MRCP coronal series and overestimated size versus pathology with bias +0.34 cm. The radiologist interobserver agreement reached ICCs 0.74 to 0.91 on the MRI sequences.

CONCLUSION

The maximum MRI IPMN size strongly correlated with but tended to overestimate the length compared to the pathology, potentially related to formalin tissue shrinkage during tissue processing.

Survival comparison of invasive intraductal papillary mucinous neoplasm versus pancreatic ductal adenocarcinoma

BACKGROUND

The aim of this study was to assess the relevance of highlighting T1a invasive intraductal papillary mucinous carcinoma as a separate subcategory and to compare the tumor biology between invasive intraductal papillary mucinous carcinoma and pancreatic ductal adenocarcinoma.

METHODS

A total of 144 and 328 consecutive patients with intraductal papillary mucinous neoplasms and pancreatic ductal adenocarcinoma, respectively, were analyzed.

RESULTS

Patients with T1a invasive intraductal papillary mucinous carcinoma comprised 25% (11/44) of the overall subject population with invasive intraductal papillary mucinous carcinoma with 5-year disease-specific survival rate being 100%. None of the patients with pancreatic ductal adenocarcinoma were classified as having T1a disease. When patients with invasive intraductal papillary mucinous carcinoma and pancreatic ductal adenocarcinoma were compared after excluding patients with T1a invasive intraductal papillary mucinous carcinoma, the 5-year disease-specific survival rates were 63% vs 40% in node-negative status (P = .018); and they were 20% vs 13% in node-positive status (P = .385). Subsequent analyses revealed that this survival superiority was limited to patients without evidence of lymphatic invasion.

CONCLUSION

T1a invasive intraductal papillary mucinous carcinoma is a clinical entity specifically observed in patients with intraductal papillary mucinous carcinoma, but not in patients with pancreatic ductal adenocarcinoma, and is associated with excellent postoperative survival outcomes. In the survival comparison after exclusion of patients with T1a tumors, when the analysis was limited to patients without lymphatic invasion or lymph node metastasis, the disease-specific survival rate remained higher in patients with invasive intraductal papillary mucinous carcinoma compared with those with pancreatic ductal adenocarcinoma, and this difference was considered as being attributable to the intrinsic indolent biological behavior of invasive intraductal papillary mucinous carcinoma. However, this survival advantage was lost once lymphatic invasion occurred.

A Review of Mucinous Cystic and Intraductal Neoplasms of the Pancreatobiliary Tract

CONTEXT.—

Although most pancreatic and bile duct neoplasms are solid, mucinous cystic neoplasms and intraductal neoplasms have been increasingly recognized even when clinically silent, thanks to the increased use of sensitive imaging techniques. Cystic and intraductal neoplasms of the pancreas are often resectable and curable and constitute about 5% of all pancreatic neoplasms. Owing to their preinvasive nature and different biology, recognition of these entities remains a major priority. Mucinous cystic neoplasms are histologically and clinically distinct from other cystic pancreatic neoplasms. Pancreatic intraductal neoplasms encompass 3 major entities: intraductal papillary mucinous neoplasm, intraductal oncocytic papillary neoplasm, and intraductal tubulopapillary neoplasm. Intraductal papillary neoplasms of bile ducts are also preinvasive mass-forming neoplasms with both similarities and differences with their pancreatic counterparts. All of these pancreatobiliary neoplasms have diverse and distinctive clinicopathologic, genetic, and prognostic variations.

OBJECTIVE.—

To review the clinical, pathologic, and molecular features of mucinous cystic and intraductal neoplasms of the pancreatobiliary tract.

DATA SOURCES.—

Literature review, diagnostic manuals, and guidelines.

CONCLUSIONS.—

This review will briefly describe well-known clinical and pathologic features and will focus on selected recently described aspects of morphology, grading, classification, and genomic alterations of cystic and intraductal neoplasms of the pancreatobiliary tract.

Radiomics in stratification of pancreatic cystic lesions: Machine learning in action

Pancreatic cystic lesions (PCLs) are well-known precursors of pancreatic cancer. Their diagnosis can be challenging as their behavior varies from benign to malignant disease. Precise and timely management of malignant pancreatic cysts might prevent transformation to pancreatic cancer. However, the current consensus guidelines, which rely on standard imaging features to predict cyst malignancy potential, are conflicting and unclear. This has led to an increased interest in radiomics, a high-throughput extraction of comprehensible data from standard of care images. Radiomics can be used as a diagnostic and prognostic tool in personalized medicine. It utilizes quantitative image analysis to extract features in conjunction with machine learning and artificial intelligence (AI) methods like support vector machines, random forest, and convolutional neural network for feature selection and classification. Selected features can then serve as imaging biomarkers to predict high-risk PCLs. Radiomics studies conducted heretofore on PCLs have shown promising results. This cost-effective approach would help us to differentiate benign PCLs from malignant ones and potentially guide clinical decision-making leading to better utilization of healthcare resources. In this review, we discuss the process of radiomics, its myriad applications such as diagnosis, prognosis, and prediction of therapy response. We also discuss the outcomes of studies involving radiomic analysis of PCLs and pancreatic cancer, and challenges associated with this novel field along with possible solutions. Although these studies highlight the potential benefit of radiomics in the prevention and optimal treatment of pancreatic cancer, further studies are warranted before incorporating radiomics into the clinical decision support system.

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.

Significance of microcystic, elongated, and fragmented glandular-like features in intraductal papillary mucinous neoplasm of the pancreas

Microcystic, elongated, and fragmented (MELF) glandular features are associated with epithelial-mesenchymal transition, invasion, and progression in endometrioid adenocarcinoma of the uterus. Similar histological features are also observed at the periphery of pancreatic intraductal papillary mucinous neoplasms (IPMNs). However, the clinicopathological significance of MELF-like features-particularly whether they represent regenerative or truly neoplastic conditions-in IPMNs remains unclear. We assessed a total of 152 surgically resected IPMNs. Fifty cases exhibited MELF-like features, including 26 cases of IPMNs with accompanying adenocarcinomas and 24 cases of IPMNs without accompanying adenocarcinomas. MELF-like features were more frequently observed in IPMN cases with accompanying adenocarcinomas, larger tumors, main-duct type, and non-gastric histologic subtype. A positive correlation between the presence of MELF-like features and high-grade dysplasia was observed in IPMNs without accompanying adenocarcinomas. Moreover, DPC4 loss and p53 overexpression in MELF-like glands were more commonly observed in IPMNs with high-grade dysplasia. IPMN patients with MELF-like features had worse overall and disease-specific survival by univariate analyses. Our observations suggest that MELF-like features in some IPMNs with high-grade dysplasia could be related to stromal invasion. Hence, when MELF-like features are observed in IPMNs, pathologists should carefully evaluate the results of microscopic examinations to identify the invasive components; and, immunohistochemical staining for DPC4 and p53 could help clarify its clinicopathological significance.

Revisions of international consensus Fukuoka guidelines for the management of IPMN of the pancreas

The management of intraductal papillary mucinous neoplasm (IPMN) continues to evolve. In particular, the indications for resection of branch duct IPMN have changed from early resection to more deliberate observation as proposed by the international consensus guidelines of 2006 and 2012. Another guideline proposed by the American Gastroenterological Association in 2015 restricted indications for surgery more stringently and recommended physicians to stop surveillance if no significant change had occurred in a pancreatic cyst after five years of surveillance, or if a patient underwent resection and a non-malignant IPMN was found. Whether or not it is safe to do so, as well as the method and interval of surveillance, has generated substantial debate. Based on a consensus symposium held during the meeting of the International Association of Pancreatology in Sendai, Japan, in 2016, the working group has revised the guidelines regarding prediction of invasive carcinoma and high-grade dysplasia, surveillance, and postoperative follow-up of IPMN. As the working group did not recognize the need for major revisions of the guidelines, we made only minor revisions and added most recent articles where appropriate. The present guidelines include updated information and recommendations based on our current understanding, and highlight issues that remain controversial or where further research is required.

Natural History of Pancreatic Cysts

Pancreatic cystic neoplasms are discovered with increasing frequency. Accurate knowledge of the natural history of cystic neoplasms is crucial to develop useful and cost-effective strategies for surveillance and surgical resection. To date, the natural history of cystic neoplasms is still incomplete due to lack of adequate diagnostic accuracy in the absence of surgical pathology. Nevertheless, current evidence points to risk factors for malignant transformation to help clinical management. New biomarkers that accurately distinguish cyst neoplasms and those most likely to progress to cancer would help clarify the natural history of cystic neoplasms.

Pathologic Evaluation and Reporting of Intraductal Papillary Mucinous Neoplasms of the Pancreas and Other Tumoral Intraepithelial Neoplasms of Pancreatobiliary Tract: Recommendations of Verona Consensus Meeting

BACKGROUND

There are no established guidelines for pathologic diagnosis/reporting of intraductal papillary mucinous neoplasms (IPMNs).

DESIGN

An international multidisciplinary group, brought together by the Verona Pancreas Group in Italy-2013, was tasked to devise recommendations.

RESULTS

(1) Crucial to rule out invasive carcinoma with extensive (if not complete) sampling. (2) Invasive component is to be documented in a full synoptic report including its size, type, grade, and stage. (3) The term "minimally invasive" should be avoided; instead, invasion size with stage and substaging of T1 (1a, b, c; ≤ 0.5, > 0.5-≤ 1, > 1 cm) is to be documented. (4) Largest diameter of the invasion, not the distance from the nearest duct, is to be used. (5) A category of "indeterminate/(suspicious) for invasion" is acceptable for rare cases. (6) The term "malignant" IPMN should be avoided. (7) The highest grade of dysplasia in the non-invasive component is to be documented separately. (8) Lesion size is to be correlated with imaging findings in cysts with rupture. (9) The main duct diameter and, if possible, its involvement are to be documented; however, it is not required to provide main versus branch duct classification in the resected tumor. (10) Subtyping as gastric/intestinal/pancreatobiliary/oncocytic/mixed is of value. (11) Frozen section is to be performed highly selectively, with appreciation of its shortcomings. (12) These principles also apply to other similar tumoral intraepithelial neoplasms (mucinous cystic neoplasms, intra-ampullary, and intra-biliary/cholecystic).

CONCLUSIONS

These recommendations will ensure proper communication of salient tumor characteristics to the management teams, accurate comparison of data between analyses, and development of more effective management algorithms.

Pathological features and diagnosis of intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a noninvasive epithelial neoplasm of mucin-producing cells arising in the main duct (MD) and/or branch ducts (BD) of the pancreas. Involved ducts are dilated and filled with neoplastic papillae and mucus in variable intensity. IPMN lacks ovarian-type stroma, unlike mucinous cystic neoplasm, and is defined as a grossly visible entity (≥ 5 mm), unlike pancreatic intraepithelial neoplasm. With the use of high-resolution imaging techniques, very small IPMNs are increasingly being identified. Most IPMNs are solitary and located in the pancreatic head, although 20%-40% are multifocal. Macroscopic classification in MD type, BD type and mixed or combined type reflects biological differences with important prognostic and preoperative clinical management implications. Based on cytoarchitectural atypia, IPMN is classified into low-grade, intermediate-grade and high-grade dysplasia. Based on histological features and mucin (MUC) immunophenotype, IPMNs are classified into gastric, intestinal, pancreatobiliary and oncocytic types. These different phenotypes can be observed together, with the IPMN classified according to the predominant type. Two pathways have been suggested: gastric phenotype corresponds to less aggressive uncommitted cells (MUC1 -, MUC2 -, MUC5AC +, MUC6 +) with the capacity to evolve to intestinal phenotype (intestinal pathway) (MUC1 -, MUC2 +, MUC5AC +, MUC6 - or weak +) or pancreatobiliary /oncocytic phenotypes (pyloropancreatic pathway) (MUC1 +, MUC 2-, MUC5AC +, MUC 6 +) becoming more aggressive. Prognosis of IPMN is excellent but critically worsens when invasive carcinoma arises (about 40% of IPMNs), except in some cases of minimal invasion. The clinical challenge is to establish which IPMNs should be removed because of their higher risk of developing invasive cancer. Once resected, they must be extensively sampled or, much better, submitted in its entirety for microscopic study to completely rule out associated invasive carcinoma.

Extraduodenal papillectomy: a feasible alternative method of total papillectomy

Rational treatment for neoplasms of the duodenal papilla (NDPs) is still controversial, especially for early stage lesions. Total papillectomies are indicated in patients expected to have adenomas, adenocarcinoma in an adenoma, or mucosal adenocarcinomas with no lymph node metastases. However, the preoperative pathological evaluation of NDPs is still challenging and often inaccurate, mainly because of the complicated anatomical structures involved and the possibility of an adenocarcinoma in an adenoma. Herein, we introduce a new method of total papillectomy, the extraduodenal papillectomy (ExDP). In this method, papillectomy is undertaken from outside of the duodenum, instead of resection from the inside through a wide incision of the duodenal wall as is done in conventional transduodenal papillectomy (TDP). The advantages of ExDP are precise and deeper cutting of the sphincter and shorter exploration time of the tumor compared to conventional TDP. We demonstrate three representative patients, all of whom had an uneventful postoperative course. One of them subsequently underwent a pylorus preserving pancreatoduodenectomy after detailed postoperative pathological evaluation. Including that patient, no recurrence has occurred with 37-46 months of follow-up. In conclusion, ExDP is regarded as a "total biopsy" for early stage borderline lesions and a feasible, less demanding alternative method for the treatment of NDPs.

IPMN: surgical treatment

PURPOSE

Cystic pancreatic tumors are being detected more frequently, and particularly, intraductal papillary mucinous neoplasia (IPMN) has recently attracted increased attention. The detection rate of IPMN has increased over the last decade; however, management of this neoplasm remains controversial.

METHODS

Based on a review of the relevant literature and the international guidelines, we discuss the diagnostic evaluation of IPMN, its treatment, and prognosis.

RESULTS

While IPMN represents only a distinct minority of all pancreatic cancers, they appear to be a relatively frequent neoplastic form of pancreatic cystic neoplasm. It may not be possible to differentiate main duct disease from branch duct disease (MD-IPMN vs. BD-IPMN) prior to surgery. This distinction has not only an impact on treatment but also on prognosis, as MD-IPMN is more often malignant. IPMN has updated consensus guideline indications for conservative and surgical resection.

CONCLUSIONS

Since patients with IPMN of the pancreas are at risk of developing recurrent IPMN and pancreatic ductal adenocarcinoma in the remnant pancreas and extrapancreatic malignancies, early recognition, treatment, and systemic surveillance are of great importance. No conclusions can be drawn from the available evidence with respect to the efficacy of surveillance and follow-up treatment programs. A better understanding of the natural course of IPMN and the biology of pancreatic cancer is mandatory to enable further diagnostic and treatment improvements.

International consensus guidelines 2012 for the management of IPMN and MCN of the pancreas

The international consensus guidelines for management of intraductal papillary mucinous neoplasm and mucinous cystic neoplasm of the pancreas established in 2006 have increased awareness and improved the management of these entities. During the subsequent 5 years, a considerable amount of information has been added to the literature. Based on a consensus symposium held during the 14th meeting of the International Association of Pancreatology in Fukuoka, Japan, in 2010, the working group has generated new guidelines. Since the levels of evidence for all items addressed in these guidelines are low, being 4 or 5, we still have to designate them "consensus", rather than "evidence-based", guidelines. To simplify the entire guidelines, we have adopted a statement format that differs from the 2006 guidelines, although the headings are similar to the previous guidelines, i.e., classification, investigation, indications for and methods of resection and other treatments, histological aspects, and methods of follow-up. The present guidelines include recent information and recommendations based on our current understanding, and highlight issues that remain controversial and areas where further research is required.

Noninvasive intraductal papillary mucinous neoplasm with para-aortic lymph node metastasis: report of a case

Intraductal papillary mucinous neoplasms (IPMNs) with an invasive carcinoma component are categorized as minimally invasive or invasive. The prognosis after resection of minimally invasive IPMNs has been reported to be similar to that after resection of noninvasive IPMNs. We report a case of noninvasive branchduct IPMN with multiple lymph node metastases, including para-aortic node involvement, treated successfully by distal pancreatectomy with lymph node dissection. The patient, a 72-year-old man, had two multilocular cysts in the pancreatic body, 22 mm and 14 mm in diameter, respectively, communicating with the main pancreatic duct. The primary tumor and nodal metastases had similar patterns of mucin expression. The primary tumor contained a region of carcinoma in situ (CIS) without histological evidence of stromal invasion; thus, it was diagnosed as minimally invasive carcinoma. We report this case to emphasize two important points: first, even small branch-duct IPMNs without any indications for resection can have a component of CIS or more advanced disease; and second, even branch-duct IPMNs without any apparent invasive component can be aggressive and spread to the lymph nodes. Therefore, nodal status should be assessed carefully in every patient, even if the primary IPMN is not advanced.

Intraductal papillary mucinous tumors of the pancreas: biology, diagnosis, and treatment

Pancreatic intraductal papillary mucinous neoplasms (IPMNs) rank among the most common cystic tumors of the pancreas. For a long time they were misdiagnosed as mucinous cystadenocarcinoma, ductal adenocarcinoma in situ, or chronic pancreatitis. Only in recent years have IPMNs been fully recognized as clinical and pathological entities, although their origin and molecular pathogenesis remain poorly understood. IPMNs are precursors of invasive carcinomas. When resected in a preinvasive state patient prognosis is excellent, and even when they are already invasive, patient prognosis is more favorable than with ductal adenocarcinomas. Subdivision into macroscopic and microscopic subtypes facilitates further patient risk stratification and directly impacts treatment. There are main duct and branch duct IPMNs, with the main duct type including the intestinal, pancreatobiliary, and oncocytic types and the branch duct type solely harboring the gastric type. Whereas main duct IPMNs have a high risk for malignant progression, demanding their resection, branch duct IPMNs have a much lower risk for harboring malignancy. Patients with small branch duct/gastric-type IPMNs (<2 cm) without symptoms or mural nodules can be managed by periodic surveillance.

Postoperative recurrence of an IPMN of the pancreas with a fistula to the stomach

We report on a case of a 74 year old man who was diagnosed with a recurrence of non-invasive carcinoma of intraductal papillary mucinous neoplasm (non-invasive IPMN) by postoperative gastroscopy (GS). A pylorus preserving pancreatico duodenectomy for IPMN in the pancreatic head was performed. A histopathological study revealed non-invasive adenocarcinoma. At first, the local recurrence of the tumor around the superior mesenteric artery circumference was diagnosed and disappeared with gemcitabine. Later, the GS showed the elevated lesion with mucin hypersecretion in the remnant stomach. The lesion had a central dip and a fistula common to the pancreas was confirmed on fisterography. We diagnosed a recurrence of IPMN and administered chemotherapy again. However, he died of his original illness. There are no reports of postoperative recurrence of IPMN checked by GS. It should be remembered that the elevated lesion of the remnant stomach is considered as one of the recurrent patterns of IPMN.

Malignant potential of intraductal papillary mucinous neoplasms of the pancreas

An intraductal papillary mucinous neoplasm (IPMN) is now a well-recognized disease entity. In general, the prognosis of IPMN is much more favorable than that of pancreatic ductal adenocarcinoma (PDAC). However, IPMN has a broad biological spectrum and it sometimes progresses, slowly showing neoplastic transformations. International consensus guidelines have been recently proposed for the management of IPMN. While they significantly contribute to appropriate management of IPMN, various issues including the natural history and malignant potential of IPMN are not fully elucidated. This review focuses on the malignant potential, including the postoperative recurrence of IPMN, coincidence of IPMN with PDAC, and extrapancreatic malignancy that may affect the long-term survival of the patients rather than IPMN itself.

Invasive intraductal papillary mucinous carcinomas of the pancreas: predictors of survival and the role of lymph node ratio

INTRODUCTION

Intraductal papillary mucinous neoplasms (IPMNs) are being increasingly recognized, and often harbor cancer. Lymph node metastases are an important prognostic factor for patients with invasive intraductal papillary carcinoma (I-IPMC), but the role of lymph node ratio (LNR) in predicting survival after surgery for I-IPMC is unknown.

METHODS

The combined databases from the Surgical Department of Massachusetts General Hospital of Boston and the University of Verona were queried. We retrospectively reviewed clinical and pathologic data of all patients with resected, pathologically confirmed, I-IPMC between 1990 and 2007. Univariate and multivariate analysis were performed.

RESULTS

I-IPMCs were diagnosed in 104 patients (55 males and 49 females), median age was 69 years. Recurrent disease was identified in 49 patients (47.1%) and the median 5-year disease specific survival (DSS) was 60.1%. The median number of resected/evaluated nodes was 15 (range, 5-60). There were 60 (57.7%) patients who had negative lymph nodes (N0), whereas 44 (42.3%) had lymph node metastases (N1). Patients with lymph node metastases had a shorter 5-year DSS (28.9%) compared with patients with negative lymph nodes (80.3%; P < 0.05) As the LNR increased, 5-year DSS decreased (LNR = 0, 86.5%; LNR >0 to 0.2, 34.4%; LNR >0.2, 11.1%; P < 0.05). On multivariate analysis, LNR, the presence of a family history of pancreatic cancer and a preoperative value of Ca 19.9 > 37 U/L were significant predictors of survival (P < 0.05).

CONCLUSIONS

Lymph node ratio is a strong predictor of survival after resection for invasive intraductal papillary mucinous carcinoma.

Inferior head resection of the pancreas for intraductal papillary mucinous neoplasms

BACKGROUND

Previous reports have suggested that patients with intraductal papillary mucinous neoplasm (IPMN) have a favorable prognosis after surgical resection. Thus, a variety of types of partial pancreatic resections have been advocated for treating these low-grade malignant tumors. However, the surgical outcome of IPMN after such limited pancreatectomy has not been fully clarified.

METHODS

We performed a retrospective review of the clinicopathologic features and surgical outcome in 15 patients who underwent inferior head resection for IPMN at the Chiba University Hospital and National Cancer Center Hospital East between July 1994 and January 2007.

RESULTS

There were 13 patients with noninvasive IPMNs (10 adenomas and 3 noninvasive carcinomas) and 2 patients with minimally invasive intraductal papillary mucinous carcinoma (minimally invasive IPMN). Complete tumor removal (R0 resection) was performed in four patients (80%) with intraductal papillary mucinous carcinoma. Subsequent pancreatoduodenectomy was performed in one patient because of noninvasive carcinoma with multiple mucous lakes in the pancreatic parenchyma. Values for N-benzoyl-L: -tyrosyl-p-aminobenzoic acid excretion test results before (n = 13) and after (n = 13) the operation were 70.7 and 66.1, showing no significant difference. The 2-h glucose levels in the 75 g oral glucose tolerance test before (n = 13) and after (n = 13) the operation were 133 and 146 mg/dl, respectively, showing no significant difference. Pancreatic fistula occurred in 7 (47%) patients. Overall morbidity and mortality rates were 67 and 0%, respectively. The overall 1-, 3-, 5-, and 10-year survival rates for the 15 patients were 100, 79, 79, and 71%, respectively. The 1-, 3-, 5-, and 10-year survival rates for patients with noninvasive IPMN (n = 13) and those with minimally invasive IPMN (n = 2) were 100, 92, 92, and 83%; and 100, 0, 0, and 0%, respectively. There was a significant difference in survival between patients with noninvasive IPMN and those with minimally invasive IPMN (p = 0.0005). No patient with noninvasive IPMN developed recurrent disease. One patient with minimally invasive IPMN died of recurrent peritoneal dissemination 18 months after margin-positive R1 resection. Two patients died of pancreatic ductal adenocarcinoma, 30 and 78 months after inferior head resection.

CONCLUSIONS

Pancreatic endocrine and exocrine function was well preserved after inferior head resection. Pancreatic fistula occurred more frequently after inferior head resection than with conventional pancreatoduodenectomy. Patients with noninvasive IPMN had favorable survivals after this procedure. However, one patient with minimally invasive IPMN with margin-positive R1 resection died of recurrent disease. Thus, margin-negative R0 resection should be performed for IPMN.

[Limited pancreatic resections for intraductal papillary mucinous neoplasm]

INTRODUCTION

For non-invasive intraductal papillary and mucinous neoplasm (IPMN) with limited extent, pancreaticoduodenectomy (PD) or distal pancreatectomy (DP) seem excessive due to the risk of pancreatic insufficiency. Enucleation (EN) or medial pancreatectomy (MP) are not commonly performed for IPMN. The aim of this study was to evaluate the feasibility and results of EN and MP for non-invasive IPMN.

PATIENTS AND METHODS

Of 249 patients with IPMN, we attempted a limited resection in 50 (20%) EN (n=31) or MP (n=20) with routine intra-operative frozen section pathology. One attempted EN was converted to MP. Indications for surgery were pain/pancreatitis (44%), suspicion of main duct involvement (28%), mural nodules in branch duct (14%), branch duct>30 mm (8%) or suspicion of mucinous cystadenoma (6%). Follow-up clinical assessment and MRI were performed on a yearly basis.

RESULTS

Of the 31 attempted enucleations, 5 (13%) were immediately converted (4 PD, 1 MP) due to technical reasons (n=3) or due to findings on frozen section (n=2). At definitive pathological examination (accuracy of frozen sectioning=98%), branch ducts were involved by mild (n=21), moderate (n=7) or high grade dysplasia (n=2). One patient underwent a double EN. Of 20 attempted medial pancreatectomies, 8 (40%) required additional segmental resection due to significant IPMN lesions at pancreatic margins; 3 of the additional resection margins were tumor-free, and 5 were involved by IPMN (4 conversions to PD or DP, one contra-indication to PD). Overall, 49 pancreatic margins were analyzed by frozen sectioning with 98% accuracy. Resected specimens of 16 MP showed involvement by mild (n=7), moderate (n=7) or high grade dysplasia (n=2). There was no postoperative mortality. Median length of stay was 21 and 30 days respectively after EN and MP. Pancreatic fistula rate was 54% and 81% respectively after EN and MP. Three patients underwent early re-operation for hemorrhage. Overall median follow-up was 24 months (3-121). All patients are alive, 2 patients (5%) have presented with recurrent pain and 4 have developed tumor recurrence on imaging follow-up (4/33=12%). Two patients (5%) developed de novo diabetes (one after EN combined with DP) and a third patient developed worsening of pre-existing diabetes plus exocrine insufficiency. No patient had surgery for recurrence.

CONCLUSIONS

EN and MP are feasible for non-invasive IPMN. Their significant early morbidity is counterbalanced by low rates of both long-term functional disorders and tumor recurrence.

Interdisciplinary management of an intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is less common than classic invasive ductal adenocarcinoma of the pancreas but is being diagnosed with greater frequency since its clinicopathologic features are now clearly defined. Often multifocal in its existence along the pancreatic duct, IPMN is associated with a significant risk for recurrence and warrants vigilant surveillance, even after a margin-negative resection.

METHODS

The authors present a case highlighting important features in the diagnosis, workup, and management of IPMN. They also review existing literature highlighting epidemiology, findings of molecular studies, and current treatment recommendations.

RESULTS

Physicians and patients must carefully weigh the risks and benefits associated with treatment options. Limited resection in a patient with a high likelihood of multifocal disease preserves pancreatic parenchyma and reduces the risk of developing pancreatic endocrine and exocrine insufficiency. Though the risk of developing invasive cancer in the remnant is small, the prognosis is worse if it does develop. Conversely, total pancreatectomy eliminates the risk of future malignancy but involves life-long insulin and exogenous pancreatic enzyme dependence and significant associated morbidity.

CONCLUSIONS

Decision making for effective treatment of IPMN is complex and requires attention to detail by an interdisciplinary team with experience in the diagnosis and management of these tumors. Treatment must be individualized based on patient life expectancy in terms of remaining years and overall quality. Molecular profiling of these lesions may allow for more precise tailoring of treatment in the future.

Intraductal papillary mucinous neoplasms of the pancreas: indication, extent, and results of surgery

In intraductal and papillary mucinous neoplasm (IPMN) of the pancreas, the aims of surgery differ according to the presence of malignancy. For malignant IPMN and especially for invasive malignancy, radical resection is essential, but entails a substantial operative risk and long-term pancreatic insufficiency. For benign IPMN, in theory, the operative risk and the loss of pancreatic function should be minimal. Thus, surgery for malignant and benign IPMN differs in patient selection, surgical technique, and accepted risk of long-term functional disorders. This article details the indications, surgical techniques, and results of surgery in IPMN.

Intraductal papillary mucinous neoplasms

Intraductal papillary mucinous neoplasm (IPMN) is characterized by enhanced mucus secretion. It is a benign or low-grade neoplasm associated with a dilated main pancreatic duct, patulous ampullary orifice, and abundant mucus secretion. Foci of aggressive cancer may arise and become invasive. Surgery is the only treatment that can cure IPMN, but the extent of pancreatic resection and the intraoperative margins remain areas of controversy. The risks of total pancreatectomy must be weighed against the risk for developing cancer in the residual pancreas. Risks must be factored against the natural course of the disease and the likelihood of malignancy developing over the life expectancy.

Intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are now a well-recognized category of slowly growing tumors with a remarkably better prognosis, even when malignant, than pancreatic ductal adenocarcinoma. Their clinical and pathohistologic features have been increasingly attracting the attention of clinicians since their first description 25 years ago. Despite its burgeoning volume recently, accumulated literature devoted to IPMN still provides a low level of evidence with regard to diagnosis, treatment, and prognosis. Therefore, we performed a Medline-based systematic review of the literature aimed at clearly defining the clinicopathologic characteristics of pancreatic IPMN and determining the best currently available evidence-based principles of diagnosis and management of patients with this disease.

Clinicopathologic features of re-resected cases of intraductal papillary mucinous neoplasms (IPMNs)

BACKGROUND

We analyzed the clinical characteristics and patterns of recurrence of intraductal papillary mucinous neoplasms (IPMNs) from 100 consecutive surgical cases.

METHODS

The average age was 62 +/- 12 years. The tumor was located in the head in 65 patients, body in 25 patients, and tail in 10 patients. Sixty-seven patients had benign IPMNs, and 33 patients had malignant IPMNs. Malignant IPMNs were observed more frequently in the head (42%) as compared with the body (20%) or tail (10%) (P < .05). During the follow-up period, 5 patients recurred and underwent second operation. In the first operation, 1 patient underwent pancreatoduodenectomy for the head tumor and the other 4 patients underwent distal pancreatectomy for the body and/or tail tumor.

RESULTS

Although histopathologic findings in the first operation were adenoma in 2 and carcinoma in 3 patients, all patients developed carcinoma by the time of the second operation. No hyperplasia developed recurrence. The overall recurrence rate for the head tumors was 1.5% (1 out of 65), whereas that for the body and tail tumors was 11.4% (4 out of 35) (P < .05). Metachronous multicentric recurrence was suspected in 4 cases.

CONCLUSIONS

These results indicate that adenomatous or carcinomatous IPMNs, especially originated from the body or tail, should be carefully observed even with a histologically negative surgical margin.

Surgical Outcome of Intraductal Papillary Mucinous Neoplasms of the Pancreas

OBJECTIVE

An increasing number of intraductal papillary mucinous neoplasms of the pancreas have been reported in recent years. However, the clinicopathologic features and surgical outcome of this neoplasm are not fully understood because of the limited number of cases. The objective of this study is to clarify the clinicopathologic features of intraductal papillary mucinous neoplasm of the pancreas and evaluate prognostic factors influencing survival.

METHODS

Eighty-two patients with intraductal papillary mucinous neoplasm undergoing surgical resection at the National Cancer Center Hospital East between April 1994 and October 2006 were retrospectively analyzed.

RESULTS

There were 31 patients with adenoma and 51 patients with carcinoma. Carcinomas were subdivided into noninvasive carcinoma (n = 14), minimally invasive carcinoma (n = 6), and invasive carcinoma (n = 31). The postoperative mortality rate was 0%. The 5-year survival rate for patients with intraductal papillary mucinous adenoma, noninvasive carcinoma, minimally invasive carcinoma, and invasive carcinoma was 80%, 78%, 83%, and 24%, respectively. Regardless of the margin status, no patient with adenoma developed recurrent disease. There were significant differences in survival between noninvasive carcinoma and invasive carcinoma (P = .016) and between minimally invasive carcinoma and invasive carcinoma (P = .030). Multivariate analysis confirmed that lymph node metastasis (P = .004) and age (P = .015) were significant prognostic factors after surgical resection of these neoplasms.

CONCLUSIONS

Patients with intraductal papillary mucinous adenoma, noninvasive carcinoma, and minimally invasive carcinoma showed favorable survival. In contrast, invasive intraductal papillary mucinous carcinoma was associated with poor survival regardless of the margin status. Nodal involvement was the strongest predictor of poor survival.

Fate of the remnant pancreas after resection of noninvasive intraductal papillary mucinous neoplasm

BACKGROUND

The risk of local recurrence in the pancreatic remnant after resection of noninvasive intraductal papillary mucinous neoplasm (IPMN) is not well defined.

STUDY DESIGN

We performed a retrospective review of a prospectively maintained pancreatic resection database that identified 78 patients who underwent resection for noninvasive IPMN between 1983 and 2006. Local recurrence was determined radiographically and confirmed either pathologically or clinically.

RESULTS

At a median followup of 40 months, 6 patients (7.7%) have recurred locally, with a median interval of 22 months (range 8 to 62 months) from the time of resection. Three patients did not undergo additional operative treatment and died of disease progression. Three patients underwent additional resection and are alive without evidence of disease. The estimated 5-year local recurrence-free survival for all patients with noninvasive IPMN is 87%. One of 50 patients (2%) with margins negative for IPMN recurred versus 4 of 23 patients (17%) with margins positive for IPMN (p=0.02).

CONCLUSIONS

Patients who have undergone resection for noninvasive IPMN require indefinite surveillance because local recurrences may be identified several years from the initial operation and be resected while still noninvasive. Although the risk of local recurrence appears to increase in the setting of positive margins, the majority of patients with positive margins have not developed local recurrence. Negative margins should be the goal of the operation when achievable with partial pancreatectomy, but the risk of local recurrence is not high enough to mandate total pancreatectomy for microscopic positive margins.