Intraductal Papillary Mucinous Neoplasms of The Pancreas: A Nationwide Registry-Based Study

Predictors of long-term survival after resection of adenocarcinoma arising from intraductal papillary mucinous neoplasm and derivation of a prognostic model: An international multicenter study (ADENO-IPMN study)

BACKGROUND

Predictors of long-term survival after resection of adenocarcinoma arising from intraductal papillary mucinous neoplasms are unknown. This study determines predictors of long-term (>5 years) disease-free survival and recurrence in adenocarcinoma arising from intraductal papillary mucinous neoplasms and derives a prognostic model for disease-free survival.

METHODS

Consecutive patients who underwent pancreatic resection for adenocarcinoma arising from intraductal papillary mucinous neoplasms in 18 academic pancreatic centers in Europe and Asia between 2010 to 2017 with at least 5-year follow-up were identified. Factors associated with disease-free survival were determined using Cox proportional hazards model. Internal validation was performed, and discrimination and calibration indices were assessed.

RESULTS

In the study, 288 patients (median age, 70 years; 52% male) were identified; 140 (48%) patients developed recurrence after a median follow-up of 98 months (interquartile range, 78.4-123), 57 patients (19.8%) developed locoregional recurrence, and 109 patients (37.8%) systemic recurrence. At 5 years after resection, the overall and disease-free survival was 46.5% (134/288) and 35.0% (101/288), respectively. On Cox proportional hazards model analysis, multivisceral resection (hazard ratio, 2.20; 95% confidence interval, 1.06-4.60), pancreatic tail location (hazard ratio, 2.34; 95% confidence interval, 1.22-4.50), poor tumor differentiation (hazard ratio, 2.48; 95% confidence interval, 1.10-5.30), lymphovascular invasion (hazard ratio, 1.74; 95% confidence interval, 1.06-2.88), and perineural invasion (hazard ratio, 1.83; 95% confidence interval, 1.09-3.10) were negatively associated with long-term disease-free survival. The final predictive model incorporated 8 predictors and demonstrated good predictive ability for disease-free survival (C-index, 0.74; calibration, slope 1.00).

CONCLUSION

A third of patients achieve long-term disease-free survival (>5 years) after pancreatic resection for adenocarcinoma arising from intraductal papillary mucinous neoplasms. The predictive model developed in the current study can be used to estimate the probability of long-term disease-free survival.

Systematic review of challenging issues in pathology of intraductal papillary mucinous neoplasms

BACKGROUND

Intraductal papillary mucinous neoplasms (IPMNs) are a cystic precursor to pancreatic cancer. IPMNs deemed clinically to be at high-risk for malignant progression are frequently treated with surgical resection, and pathological examination of the pancreatectomy specimen is a key component of the clinical care of IPMN patients.

METHODS

Systematic literature reviews were conducted around eight topics of clinical relevance in the examination of pathological specimens in patients undergoing resection of IPMN.

RESULTS

This review provides updated perspectives on morphological subtyping of IPMNs, classification of intraductal oncocytic papillary neoplasms, nomenclature for high-grade dysplasia, assessment of T stage, distinction of carcinoma associated or concomitant with IPMN, role of molecular assessment of IPMN tissue, role of intraoperative assessment by frozen section, and preoperative evaluation of cyst fluid cytology.

CONCLUSIONS

This analysis provides the foundation for data-driven approaches to several challenging issues in the pathology of IPMNs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Long-term (10-year) outcomes and prognostic factors in resected intraductal papillary mucinous neoplasm tumors in Finland: A nationwide retrospective study

BACKGROUND

The degree of dysplasia is the most important prognostic factor for patients with resected intraductal papillary mucinous neoplasms. Intraductal papillary mucinous neoplasms are predominantly premalignant conditions; in most cases, surveillance is an adequate treatment. If worrisome features are present, surgery should be considered. However, there is limited data on the long-term prognosis of resected intraductal papillary mucinous neoplasms. We aimed to ascertain the nationwide survival of patients with resected intraductal papillary mucinous neoplasms and identify factors associated with survival.

METHODS

This is a retrospective nationwide cohort study. All intraductal papillary mucinous neoplasms operated on in Finland between 2000 and 2008 were identified. Patient records were evaluated, and original radiologic data and histologic samples were re-evaluated. Survival data were collected after a 10-year follow-up period.

RESULTS

Out of 2,024 pancreatic resections, 88 were performed for intraductal papillary mucinous neoplasm. The median age of the patients was 65 years. Histologic diagnoses were main duct intraductal papillary mucinous neoplasm 47/88 (53,4%), mixed-type intraductal papillary mucinous neoplasm 27/88 (30.7%), and branchduct intraductal papillary mucinous neoplasm 14/88 (15.9%). Of the tumors, 40/88 (45.5%) were low-grade dysplasia, 9/88 (10.2%) high-grade, and 39/88 (44.3%) were invasive cancer. The median survival was 121 (range 0-252) months. Ten-year survival was 72.5%, 66.7%, and 23.1% in the low-grade dysplasia, high-grade dysplasia, invasive cancer groups, respectively. Ten-year mortality for pancreatic cancer was 5%, 9.1%, and 71.8% in the low-grade dysplasia, high-grade dysplasia, invasive cancer groups, respectively.

CONCLUSION

Overall, 44.3% of the patients had a malignant tumor, and three-quarters (74.5%) of the main duct intraductal papillary mucinous neoplasms were malignant or high-grade dysplasia at the time of surgery. Ten-year survival was significantly better in patients operated on at the stage of a premalignant tumor (low-grade dysplasia + high-grade dysplasia) than in patients operated on at the stage of a malignant tumor.

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

BACKGROUND

The clinical importance of intraductal papillary mucinous neoplasm (IPMN) have increased last decades. Long-term survival after resection for invasive IPMN (inv-IPMN) compared to conventional pancreatic ductal adenocarcinoma (PDAC) is not thoroughly delineated.

OBJECTIVE

This study, based on the Swedish national pancreatic and periampullary cancer registry aims to elucidate the outcome after resection of inv-IPMN compared to PDAC.

METHODS

All patients ≥18 years of age resected for inv-IPMN and PDAC in Sweden between 2010 and 2019 were included. Clinicopathological variables were retrieved from the national registry. The effect on death was assessed in two multivariable Cox regression models, one for patients resected 2010-2015, one for patients resected 2016-2019. Median overall survival (OS) was estimated using the Kaplan-Meier method.

RESULTS

We included 1909 patients, 293 inv-IPMN and 1616 PDAC. The most important independent predictors of death in multivariable Cox regressions were CA19-9 levels, venous resection, tumour differentiation, as well as T-, N-, M-stage and surgical margin. Tumour type was an independent predictor for death in the 2016-2019 cohort, but not in the 2010-2015 cohort. In Kaplan-Meier survival analysis, inv-IPMN was associated with longer median OS in stage N0-1 and in stage M0 compared to PDAC. However, in stage T2-4 and stage N2 median OS was similar, and in stage M1 even shorter for inv-IPMN compared to PDAC.

CONCLUSION

In this population-based nationwide study, outcome after resected inv-IPMN compared to PDAC is more favourable in lower stages, and similar to worse in higher.

Diagnostic performance of magnetic resonance image for malignant intraductal papillary mucinous neoplasms: the importance of size of enhancing mural nodule within cyst

PURPOSE

To investigate the clinical significance of enhancing mural nodules ≥ 5 mm by comparing the diagnostic performance of high-risk stigmata for diagnosing the malignant IPMN between the international consensus guideline (ICG) 2012 and 2017 in pancreatic magnetic resonance image (MRI).

MATERIALS AND METHODS

In this retrospective study, we reviewed preoperative pancreatic MRI with surgically confirmed IPMNs between May 2009 and April 2021. High-risk stigmata, defined by ICG 2012 and ICG 2017, associated with malignant IPMN were evaluated using logistic regression analysis. We calculated and compared the sensitivity and specificity of ICG 2012 and ICG 2017 for diagnosing malignant IPMNs. Receiver-operating characteristic (ROC) curves were used to compare ICG 2012 to ICG 2017.

RESULTS

A total of 73 patients (43 men and 30 women; mean age, 69 years; standard deviation, 8 years) with 34 malignant IPMNs and 39 benign IPMNs were included. Among high-risk stigmata, enhancing mural nodule ≥ 5 mm, and MPD diameter ≥ 10 mm were the significant predictor of malignant IPMN, in multivariate logistic regression (P < 0.001 for all). For the diagnosis of malignant IPMN, the specificity of ICG 2017 for enhancing mural nodules ≥ 5 mm as the high-risk stigmata was significantly higher than that of ICG 2012 (87.2% vs. 64.1%, P = 0.008). However, there was no significant difference in sensitivity between the two guidelines (94.1% vs. 97.1%, P = 1.0). The comparison of the ROC curves showed that the diagnostic performance of ICG 2017 for malignant IPMNs (AUC, 0.91) significantly improved when compared to that of ICG 2012 (AUC, 0.81) (P = 0.01).

CONCLUSION

When applying enhancing mural nodule ≥ 5 mm as a high-risk stigmata, ICG 2017 provided a significantly higher specificity than ICG 2012 without a reduction in sensitivity.

Pancreatic Cystic Lesions and Malignancy: Assessment, Guidelines, and the Field Defect

The widespread use of high-spatial-resolution cross-sectional imaging has led to an increase in detection of incidental pancreatic cystic lesions. These lesions are a diverse group, ranging from indolent and premalignant lesions to invasive cancers. The diagnosis of several of these lesions can be suggested on the basis of their imaging appearance, while many other lesions require follow-up imaging and/or aspiration. The smaller cystic lesions, often branch-duct intraductal papillary mucinous neoplasms, have overlapping imaging characteristics that make diagnostic assessment of the natural history and malignancy risk confusing. Expert panels have developed societal guidelines, based on a consensus, for surveillance of these lesions. However, these guidelines are often inconsistent and are constantly evolving as additional scientific data are accumulated. Identification of features associated with increased risk of malignancy is important for proper management. The concept of field defect, whereby pancreatic adenocarcinoma develops at a site different from the site of the pancreatic cyst, adds to the complexity of screening guidelines. As a result of the differences in guidelines, key stakeholders (eg, radiologists, gastroenterologists, and surgeons) must review and come to a consensus regarding which guideline, or combination of guidelines, to follow at their individual institutions. Standardized reporting and macros are helpful for ensuring the uniformity of interpretations. Radiologists play a critical role in the detection and characterization of pancreatic cystic lesions, in the follow-up recommendations for these lesions, and in the detection of associated cancer. An invited commentary by Zaheer is available online. Online supplemental material is available for this article. ^©RSNA, 2021.

The European evidence-based guidelines on pancreatic cystic neoplasms (PCN) in clinical practice: The development of relative and absolute indications for surgery during prospective IPMN surveillance

INTRODUCTION

The European evidence-based guidelines on PCN recommend surveillance for IPMN patients who are fit for surgery but who have no indication for immediate surgery. Our aim was to demonstrate the feasibility of the new guidelines in clinical practice.

METHODS

This is a prospective cohort study of patients included in the IPMN register in Tampere University Hospital, Finland. IPMN was diagnosed from January 1, 2013 to December 31, 2018. Patients were analyzed for surveillance and indications for surgery according to the European guidelines on PCN.

RESULTS

Out of 128 patients in register 23 was decided to operate upfront and 105 patients were included in the surveillance programme. Invasive carcinoma was found in 4/23 of operated patients. Median follow-up time was 26 months (6-69). Median size of the cyst at the beginning and end of the surveillance was 16 mm (4-58 mm). During surveillance 0/105 (0.0%) patients had or developed an absolute indication for surgery. Relative indication for surgery was present in 8/105 (7.6%) patients in the beginning surveillance and 9/105 (8.6%) patients developed at least one relative indication for surgery during surveillance. From the surveillance cohort 2/105 patients were operated. Surveillance was abandoned in 15/105 (14.1%) patients all due to poor general condition or other medical conditions.

CONCLUSIONS

In clinical practice, surveillance of IPMN according to the European guidelines on PCN is feasible. Among our patients 16% were detected to have relative indications for surgery during the median 26 (range 3-135) months of surveillance. Nearly 15% became surgically unfit during surveillance period.

Gastric cancer in the remnant stomach after pancreaticoduodenectomy: A case series

BACKGROUND

Gastric cancer (GC) occasionally develops in the remnant stomach following pancreaticoduodenectomy (PD). In those who have undergone PD for adenocarcinoma, however, the interval and frequency of anastomotic GC are unknown.

METHODS

We searched our institutional database for patients who had undergone PD for adenocarcinoma and subsequently developed GC between 1994 and 2018 and found six patients. We summarized the clinicopathologic features and prognosis of these patients with anastomotic GC.

RESULTS

The median interval from PD to development of GC was 111.5 months. Four patients underwent curative resection of gastrojejunal anastomosis. Pathologic analysis showed signet ring cell carcinoma in four patients. The median overall survival after developing GC was 61 months.

CONCLUSION

Our findings indicate that GC in the remnant stomach after PD is rare but can occur at gastrojejunostomy anastomosis after a prolonged period. Periodic and long-term follow-up +/- surveillance endoscopy to facilitate early detection of GC in the remnant stomach is recommended, particularly for symptomatic patients. Recognition of the anastomotic tumor as a second primary and not a pancreatic ductal adenocarcinoma recurrence/metastasis is crucial in the optimal treatment of these patients, as curative resection of early-stage GC may prolong survival.