Invasive IPMN relapse later and more often in lungs in comparison to pancreatic ductal adenocarcinoma

BACKGROUND

The different oncological outcomes of invasive intraductal papillary mucinous neoplasm (I-IPMN) and pancreatic ductal adenocarcinoma (PDAC) are debated. This study aimed to compare disease recurrence patterns and histopathological characteristics in patients with resected I-IPMN and PDAC.

METHODS

Consecutive patients undergoing surgical resection for stage I-III I-IPMN or PDAC between 2010 and 2016 were retrospectively analyzed. Patients treated with neoadjuvant therapy or resected for Tis neoplasia were excluded. All surgical specimens were re-staged according to AJCC-8th-edition.

RESULTS

A total of 330 patients were included, of whom 43 had I-IPMN and 287 had PDAC. Median follow-up time was 26.7 (1.3-92.3) months and estimated median disease-free survival (DFS) was 60.3 months (47.2-73.4) for I-IPMN and 23.8 (19.3-28.2) months for PDAC (p < 0.001). During follow-up, 32.6% of I-IPMN and 67.9% of PDAC patients experienced recurrence (p < 0.001). The sites of first recurrence were the lungs (38.5% vs 13.1%, p = 0.027), liver (28.6% vs 45.0%, p = 0.180) and local (15.4% vs 36.6%, p = 0.101) for I-IPMN and PDAC, respectively. At multivariate analysis, I-IPMN histology remained an independent predictive factor for longer DFS (OR 0.528, CI 95% 0.278-1.000, p = 0.050), regardless of stage or adjuvant chemotherapy. I-IPMN and PDAC differed in rates of neuroinvasion (51.2% vs 97.2%) and positive lymph node status (N+) (46.5% vs 82.7%), especially in patients with lower T status.

CONCLUSION

I-IPMN showed a different recurrence pattern compared to PDAC, with a higher lung tropism, and longer DFS. This different biological behavior is associated with lower rates of neuroinvasion and nodal involvement, especially in early-stage disease.

Nomograms predicting long-term survival in patients with invasive intraductal papillary mucinous neoplasms of the pancreas: A population-based study

BACKGROUND

There are few effective tools to predict survival in patients with invasive intraductal papillary mucinous neoplasms of the pancreas.

AIM

To develop comprehensive nomograms to individually estimate the survival outcome of patients with invasive intraductal papillary mucinous neoplasms of the pancreas.

METHODS

Data of 1219 patients with invasive intraductal papillary mucinous neoplasms after resection were extracted from the Surveillance, Epidemiology, and End Results database, and randomly divided into the training (n = 853) and the validation (n = 366) cohorts. Based on the Cox regression model, nomograms were constructed to predict overall survival and cancer-specific survival for an individual patient. The performance of the nomograms was measured according to discrimination, calibration, and clinical utility. Moreover, we compared the predictive accuracy of the nomograms with that of the traditional staging system.

RESULTS

In the training cohort, age, marital status, histological type, T stage, N stage, M stage, and chemotherapy were selected to construct nomograms. Compared with the American Joint Committee on Cancer 7^th staging system, the nomograms were generally more discriminative. The nomograms passed the calibration steps by showing high consistency between actual probability and nomogram prediction. Categorial net classification improvements and integrated discrimination improvements suggested that the predictive accuracy of the nomograms exceeded that of the American Joint Committee on Cancer staging system. With respect to decision curve analyses, the nomograms exhibited more preferable net benefit gains than the staging system across a wide range of threshold probabilities.

CONCLUSION

The nomograms show improved predictive accuracy, discrimination capability, and clinical utility, which can be used as reliable tools for risk classification and treatment recommendations.