Diagnostic Performance of Surgical Indication for Branch-duct or Mixed-type Intraductal Papillary Mucinous Neoplasms of the Revised International Association of Pancreatology (IAP) 2023 Guidelines.

OBJECTIVE: To evaluate the diagnostic performance of surgical indications of the revised International Association of Pancreatology (IAP) 2023 guidelines compared to the IAP 2017 and European 2018 guidelines. SUMMARY BACKGROUND DATA: The revised IAP guidelines for surgical indications for branch duct (BD) intraductal papillary mucinous neoplasms (IPMN) include the presence of at least two worrisome features without mandatory endoscopic ultrasound. METHODS: Among 663 patients who underwent resection for pathologically confirmed IPMN in a tertiary hospital between 2013 and 2023, 556 patients with BD or mixed-type IPMN were retrospectively reviewed. Diagnostic performances of the three guidelines for predicting high-grade dysplasia or IPMN with invasive carcinoma were compared. The primary outcome was the malignancy rate. Clinicopathological and radiological imaging data were analyzed. RESULTS: A total of 540, 451, and 490 patients met the surgical indications of the IAP, 2017, 2023, and European guidelines, respectively. Malignant IPMN was observed in 229 (41.2%) patients (high-grade dysplasia, n=99; invasive carcinoma, n=130). Surgical indication by the IAP 2023 guidelines showed higher specificity (29.1 vs. 4.9%, P<0.001), positive predictive value (48.6 vs. 42.4%, P=0.031), and accuracy (55.5 vs. 44.1%, P<0.001) than the IAP 2017 guidelines. It also had higher specificity than the European guidelines (18.7%, P=0.024). The IAP 2023 guidelines showed a superior AUC of surgical indication (0.623 vs. 0.582 for the European guidelines, P<0.001; and 0.524 for the IAP guidelines, P=0.008). CONCLUSIONS: The IAP 2023 guidelines showed better malignancy prediction than the IAP 2017 and European guidelines, potentially reducing unnecessary surgeries.

Long-Term Outcome of Proximal Gastrectomy for Upper-Third Advanced Gastric and Siewert Type II Esophagogastric Junction Cancer Compared With Total Gastrectomy: A Propensity Score-Matched Analysis.

BACKGROUND: This study aimed to investigate the oncologic long-term safety of proximal gastrectomy for upper-third advanced gastric cancer (AGC) and Siewert type II esophagogastric junction (EGJ) cancer. METHODS: The study enrolled patients who underwent proximal gastrectomy (PG) or total gastrectomy (TG) with standard lymph node (LN) dissection for pathologically proven upper-third AGC and EGJ cancers between January 2007 and December 2018. Propensity score-matching with a 1:1 ratio was performed to reduce the influence of confounding variables such as age, sex, tumor size, T stage, N stage, and tumor-node-metastasis (TNM) stage. Kaplan-Meier survival analysis was performed to analyze oncologic outcome. The prognostic factors of recurrence-free survival (RFS) were analyzed using the Cox proportional hazard analysis. RESULTS: Of the 713 enrolled patients in this study, 60 received PG and 653 received TG. Propensity score-matching yielded 60 patients for each group. The overall survival rates were 61.7 % in the PG group and 68.3 % in the TG group (p = 0.676). The RFS was 86.7 % in the PG group and 83.3 % in the TG group (p = 0.634). The PG group showed eight recurrences (1 anastomosis site, 1 paraaortic LN, 1 liver, 1 spleen, 1 lung, 1 splenic hilar LN, and 2 remnant stomachs). In the multivariate analysis, the operation method was not identified as a prognostic factor of tumor recurrence. CONCLUSION: The patients who underwent PG had a long-term oncologic outcome similar to that for the patients who underwent TG for upper-third AGC and EGJ cancer.

Comparing clinical and genomic features based on the tumor location in patients with resected pancreatic cancer.

BACKGROUND: Pancreatic cancer is anatomically divided into pancreatic head and body/tail cancers, and some studies have reported differences in prognosis. However, whether this discrepancy is induced from the difference of tumor biology is hotly debated. Therefore, we aimed to evaluate the differences in clinical outcomes and tumor biology depending on the tumor location. METHODS: In this retrospective cohort study, we identified 800 patients with pancreatic ductal adenocarcinoma who had undergone upfront curative-intent surgery. Cox regression analysis was performed to explore the prognostic impact of the tumor location. Among them, 153 patients with sufficient tumor tissue and blood samples who provided informed consent for next-generation sequencing were selected as the cohort for genomic analysis. RESULTS: Out of the 800 patients, 500 (62.5%) had pancreatic head cancer, and 300 (37.5%) had body/tail cancer. Tumor location in the body/tail of the pancreas was not identified as a significant predictor of survival outcomes compared to that in the head in multivariate analysis (hazard ratio, 0.94; 95% confidence interval, 0.77-1.14; P = 0.511). Additionally, in the genomic analyses of 153 patients, there were no significant differences in mutational landscapes, distribution of subtypes based on transcriptomic profiling, and estimated infiltration levels of various immune cells between pancreatic head and body/tail cancers. CONCLUSIONS: We could not find differences in prognosis and tumor biology depending on tumor location in pancreatic ductal adenocarcinoma. Discrepancies in prognosis may represent a combination of lead time, selection bias, and clinical differences, including the surgical burden between tumor sites.

Clinical outcomes of preservation versus resection of portal/superior mesenteric vein during pancreaticoduodenectomy in pancreatic cancer patients who respond to neoadjuvant treatment: A retrospective cohort study.

BACKGROUND: R0 rates have increased as neoadjuvant treatment (NAT) has become the primary treatment for pancreatic ductal adenocarcinoma (PDAC) with venous involvement, suggesting a decrease in venous tumor infiltration. The aim of this study was to investigate the clinical outcomes of preserving the portal/superior mesenteric vein (PV/SMV) during pancreaticoduodenectomy (PD) in PDAC patients who underwent NAT. MATERIAL AND METHODS: The 113 patients with resectable and borderline resectable PDAC with venous involvement who responded to NAT and underwent curative PD between 2012 and 2022 were retrospectively reviewed. RESULTS: Among the 113 patients, PV/SMV preservation (PVP) was performed in 68 patients (60.2%), and PV/SMV resection (PVR) was performed in 45 patients (39.8%). There was no significant difference in the R0 rate, 5-year overall survival (OS) and recurrence-free survival between the two groups. PV/SMV stenosis within 3 months after surgery was more common in the PVR group than in the PVP group (1.5% versus 22.2%; P < 0.001), and 5-year PV/SMV stenosis-free survival was significantly higher in the PVP group than in the PVR group (76.5% versus 53.4%; P=0.014). Multivariate analysis showed that gemcitabine-based neoadjuvant chemotherapy was associated with poor OS. PVR, clinically relevant postoperative pancreatic fistula, and locoregional recurrence were independent risk factors for PV/SMV stenosis. CONCLUSION: The PVP group had similar oncologic outcomes and better vessel-functional outcomes than the PVR group. Therefore, if dissection is possible and there is a high likelihood of achieving R0 resection after NAT, routine PVR may be unnecessary in PDAC patients with venous involvement.

Re-evaluation of risk and oncological outcomes of resection of veins and arteries in the resection of pancreatic cancer.

BACKGROUND: Advances in chemotherapy have led to increasing major vascular resection during pancreatectomy which has been contraindicated due to high morbidity. This study aimed to verify the safety and oncological outcomes of vascular resection during pancreatectomy in the era of neoadjuvant therapy. METHODS: Data from patients who underwent surgery for pancreatic cancer at Seoul National University Hospital between 2001 and 2021 were reviewed. Clinicopathological outcomes were analyzed according vessel resection. A propensity-score-matched (PSM) analysis was performed to evaluate survival outcomes. RESULTS: Of 1596 patients, the proportion of those who underwent vascular resection increased from 9.2% to 23.4% over time divided into 5-year intervals. There were no differences in major complications (15.6% vs. 13.0%; p = .266) and 30-day mortality rate (0.3% vs. 0.6%; p = .837) between the vascular and nonvascular resection groups. After PSM, the vascular resection group demonstrated comparable survival outcome with the nonvascular resection group (5 year-survival-rate 20.4 vs. 23.7%; p = .194). Arterial resection yielded comparable survival outcome with nonvascular resection (5 year-survival-rate 38.1% vs. 23.7%; p = .138). CONCLUSIONS: Appropriate vascular resection-even arterial-is safe and effective in patients carefully selected for radical surgery in the era of neoadjuvant therapy. Further studies are needed to determine the optimal indication and method for vascular resection in patients with pancreatic cancer.

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

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