Dong Wook Choi

Treatment Guidelines for Branch Duct Type Intraductal Papillary Mucinous Neoplasms of the Pancreas: When Can We Operate or Observe?

BackgroundThe objectives of this study were to investigate the clinicopathological features of branch intraductal papillary mucinous neoplasm (IPMN) and to determine safe criteria for its observation. Most clinicians agree that surgical resection is required to treat main duct-type IPMN because of its high malignancy rate. However, no definite treatment guideline (with respect to surgery or observation) has been issued on the management of branch duct type IPMN.MethodsWe retrospectively reviewed the clinicopathological data of 138 patients who underwent operations for IPMN between 1993 and 2006 at five institutes in Korea.ResultsOf 138 patients (mean age, 60.6 years; 87 men, 51 women), 76 underwent pancreatoduodenectomy, 39 distal pancreatectomy, 4 total pancreatectomy, and 20 limited pancreatic resection. There were 112 benign cases: 47 adenoma, 63 borderline cases, and 26 malignant cases, with 9 of these being noninvasive and 17 invasive. By univariate analysis, tumor size and the presence of a mural nodule were identified as meaningful predictors of malignancy. By receiver operating characteristic curve analysis, a tumor size of >2 cm was found to be the most valuable predictor of malignancy. When cases were classified according to tumor size and the presence of a mural nodule, the malignancy rate for a tumor ≤2 cm without a mural nodule was 9.2%, for a tumor of ≤2 cm plus a mural nodule was 25%, and for other conditions such as tumor >2 cm, >25%.ConclusionsMany branch duct IPMNs are malignant. Surgical treatment is recommended, except in cases that are strongly suspected to be benign or cases that present a high operative risk. Observation is only recommended in patients with a tumor size of ≤2 cm without a mural nodule.

Surgical strategies for non-functioning pancreatic neuroendocrine tumours.

The purpose of this study was to identify management strategies for non‐functioning pancreatic neuroendocrine tumours (NF‐PNETs) by analysis of surgical outcomes at a single institution.

Prognostic Factors and Adjuvant Chemoradiation Therapy After Pancreaticoduodenectomy for Pancreatic Adenocarcinoma

BackgroundThe aim of this study was to determine prognostic factors for survival after resection of pancreatic adenocarcinoma (PC) and to compare outcomes after surgery alone versus surgery plus adjuvant therapy.MethodsWe performed a retrospective review of 219 patients who underwent pancreaticoduodenectomy for PC with curative intent between 1995 and 2007. Data were collected prospectively. Postoperative adjuvant chemoradiation therapy (CRT) consisted of fluorouracil or gemcitabine-based chemotherapy; the median radiation dose was 45xa0Gy.ResultsThe 3- and 5-year overall survival (OS) rates were 24.3% and 14.2%, respectively. Median OS was 14.0xa0months [95% confidence interval (CI), 12–16xa0months]. Patients with metastatic lymph nodes experienced improved median survival (16 vs 10xa0months; Pu2009<u20090.001) and 3-year OS (3-year OS 28% vs 8%) after adjuvant CRT compared with those who had no CRT. Patients who underwent non-curative resection had the same effect (median OS, 13 vs 8xa0months; Pu2009=u20090.037). Lymph node metastasis and non-curative resection showed no significance on multivariate analysis. Poor differentiation [risk ratio (RR)u2009=u20092.10; Pu2009<u20090.001] and tumor size >3xa0cm (RRu2009=u20091.57; Pu2009=u20090.018) were found to be adverse prognostic factors; adjuvant CRT had borderline significance (RRu2009=u20090.70; Pu2009=u20090.087).ConclusionsAdjuvant CRT benefited a subset of patients with resected PC, particularly those with lymph node metastasis and those undergoing non-curative resection. Multivariate analysis demonstrated that patients with tumors larger than 3xa0cm and poor differentiation had poor prognosis.

Intratumoral heterogeneity of 18 F-FDG uptake predicts survival in patients with pancreatic ductal adenocarcinoma

PurposeTo assess whether intratumoral heterogeneity measured by 18F-FDG PET texture analysis has potential as a prognostic imaging biomarker in patients with pancreatic ductal adenocarcinoma (PDAC).MethodsWe evaluated a cohort of 137 patients with newly diagnosed PDAC who underwent pretreatment 18F-FDG PET/CT from January 2008 to December 2010. First-order (histogram indices) and higher-order (grey-level run length, difference, size zone matrices) textural features of primary tumours were extracted by PET texture analysis. Conventional PET parameters including metabolic tumour volume (MTV), total lesion glycolysis (TLG), and standardized uptake value (SUV) were also measured. To assess and compare the predictive performance of imaging biomarkers, time-dependent receiver operating characteristic (ROC) curves for censored survival data and areas under the ROC curve (AUC) at 2xa0years after diagnosis were used. Associations between imaging biomarkers and overall survival were assessed using Cox proportional hazards regression models.ResultsThe best imaging biomarker for overall survival prediction was first-order entropy (AUCu2009=u20090.720), followed by TLG (AUCu2009=u20090.697), MTV (AUCu2009=u20090.692), and maximum SUV (AUCu2009=u20090.625). After adjusting for age, sex, clinical stage, tumour size and serum CA19-9 level, multivariable Cox analysis demonstrated that higher entropy (hazard ratio, HR, 5.59; Pu2009=u20090.028) was independently associated with worse survival, whereas TLG (HR 0.98; Pu2009=u20090.875) was not an independent prognostic factor.ConclusionIntratumoral heterogeneity of 18F-FDG uptake measured by PET texture analysis is an independent predictor of survival along with tumour stage and serum CA19-9 level in patients with PDAC. In addition, first-order entropy as a measure of intratumoral metabolic heterogeneity is a better quantitative imaging biomarker of prognosis than conventional PET parameters.

Predicting recurrence of pancreatic solid pseudopapillary tumors after surgical resection: a multicenter analysis in Korea.

Background:Solid pseudopapillary tumors (SPTs) of the pancreas are still considered a surgical enigma. Many clinical research trials have failed to identify prognostic factors that predict the malignant behavior of SPTs. Materials and Methods:This work was a retrospective multicenter study that included a total of 17 medical institutions. Data from 351 patients who underwent surgical resection from January 1990 to December 2008 were retrospectively collected using standardized case report forms requesting clinicopathologic features. Results:Thirty-four patients (9.7%) were male, and 317 (90.3%) were female, with a mean age of 36.8 ± 12.4 years. Recently, minimally invasive (P < 0.001) and parenchyma or function-preserving limited surgeries (P = 0.016) have been more frequently applied for the treatment of pancreatic SPTs. Ninety-eight patients (27.9%) had microscopic malignant features. Only 9 patients (2.6%) experienced tumor recurrence after the initial pancreatic SPT resection. Multivariate analysis showed that a tumor size larger than 8 cm [Exp (&bgr;) = 7.385, P = 0.018], microscopic malignant features [Exp (&bgr;) = 10.009, P = 0.011], and stage IV [Exp (&bgr;) = 42.003, P = 0.002] were significant prognostic factors for tumor recurrence. When combined with stage IV, the microscopic malignant features and 2010 World Health Organization definition of solid pseudopapillary carcinoma more successfully differentiated future recurrence risk groups (P < 0.001). Conclusions:More specific pathologic descriptions need to be employed in pathologic report forms to provide proper information to predict SPT recurrence after resection. Future studies emphasizing the standardized pathologic evaluation of pancreatic SPTs may unveil the enigmatic nature of pancreatic SPTs.

Prognostic relevance of pathologic subtypes and minimal invasion in intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas are classified into the following four histopathologic subtypes: gastric, intestinal, pancreatobiliary, and oncocytic. However, the clinicopatholgic characteristics of IPMN subtypes have not been fully clarified. Recently, a subgroup classification of minimally invasive intraductal papillary mucinous carcinomas (MI-IPMCs) was suggested in contrast to overt invasive carcinoma from IPMCs (IC-IPMCs). The purpose of this study was to determine whether or not the pathologic subtype classification can predict prognosis and to validate the usefulness of the newly proposed diagnostic criteria of MI-IPMCs. We reviewed the clinicopathologic characteristics of 142 surgically resected cases of IPMNs. There were 54, 56, 30, and two cases of the gastric, intestinal, pancreatobiliary, and oncocytic types of IPMNs, respectively. The intestinal and pancreatobiliary types were more likely to have a main duct type. All gastric type tumors were adenomas or moderate dysplasia, whereas greater than one half of the intestinal and pancreatobiliary types were carcinomas in situ or invasive carcinomas. A significant difference in recurrence and death rate was noted for invasive carcinoma between the intestinal and pancreatobiliary types. The majority of MI-IPMCs were the intestinal type, whereas the majority of IC-IPMCs were the pancreatobiliary type. The IC-IPMC group showed a decreased recurrence-free and overall survival with statistically significance (pu2009<u20090.001 and pu2009=u20090.001, respectively). Our results suggest that the pathologic subtype classification and the newly proposed diagnostic criteria for minimal invasion may also be useful to predict prognosis of IPMNs of the pancreas.

Clinical Validation of the ISGPF Classification and the Risk Factors of Pancreatic Fistula Formation Following Duct-to-Mucosa Pancreaticojejunostomy by One Surgeon at a Single Center

BackgroundPostoperative pancreatic fistula remains a troublesome complication after pancreatoduodenectomy (PD), and many authors have suggested factors that affect pancreatic leakage after PD. The International Study Group on Pancreatic Fistula (ISGPF) published a classification, but the new criteria adopted have not been substantially validated. The aims of this study were to validate the ISGPF classification and to analyze the risk factors of pancreatic leakage after duct-to-mucosa pancreatojejunostomy by a single surgeon.MethodsAll patient data were entered prospectively into a database. The risk factors for pancreatic fistula were analyzed retrospectively for 247 consecutive patients who underwent conventional pancreatoduodenectomy or pylorus-preserving pancreatoduodenectomy between June 2005 and March 2009 at the Samsung Medical Center by a single surgeon. Duct-to-mucosa pancreatojejunostomy was performed on all patients. The ISGPF criteria were used to define postoperative pancreatic fistula.ResultsConventional pancreatoduodenectomy was performed in 84 patients and pylorus-preserving pancreatoduodenectomy in 163. Postoperative complications occurred in 144 (58.3%) patients, but there was no postoperative in-hospital mortality. Pancreatic fistula occurred in 105 (42.5%) [grade A, 82 (33.2%); grade B, 9 (3.6%); grade C, 14 (5.7%)]. However, no difference was evident between the no fistula group and the grade A fistula group in terms of clinical findings, including postoperative hospital stays (11 versus 12xa0days, respectively, pu2009=u20090.332). Mean durations of hospital stay in the grade B and C fistula groups were significantly longer than in the no fistula group (21 and 28.5xa0days, respectively; pu2009<u20090.001). Multivariate analysis revealed that a soft pancreas and a long operation time (>300xa0min) were individually associated with pancreatic fistula formation of grades B and C.ConclusionsAlthough the new ISGPF classification appears to be sound in terms of postoperative pancreatic leakage, grade A fistulas lack clinical implications; thus, we are of the opinion that only grade B and C fistulas should be considered in practice. A soft pancreatic texture and an operation time exceeding 300xa0min were found to be risk factors of grade B and C pancreatic fistulas.

Role of Radical Antegrade Modular Pancreatosplenectomy for Adenocarcinoma of the Body and Tail of the Pancreas

AbstractBackgroundnStudies have claimed that in the surgical treatment of pancreas body and tail cancer, radical antegrade modular pancreatosplenectomy (RAMPS) is associated with effective tangential margin and extensive lymph node dissection. In the present study, the authors have compared the surgical outcomes between RAMPS and conventional distal pancreatosplenectomy (DPS) in patients with adenocarcinoma of the pancreas body and tail, and also identified prognostic factors associated with survival after surgery.MethodsRetrospective review of 92 consecutive patients who underwent surgical resection for pancreas body and tail adenocarcinoma with curative intent between 1995 and 2010. Median follow-up duration was 16.1xa0months.ResultsOf the 92 patients, 38 patients received RAMPS and 54 patients received DPS. Patients who underwent RAMPS had a greater number of retrieved lymph nodes than patients undergoing DPS [median 14 (5–52) vs. 9 (1–36), pxa0<xa00.05]. Conventional DPS, no adjuvant chemoradiation therapy (CRT), and non-curative resection were associated with poor overall survival (OS) on univariate analysis. After multivariate analysis for these variables, only the lack of adjuvant CRT and resection margin status were found to adversely affect OS.ConclusionsWhile the RAMPS procedure is effective in performing an extensive LN dissection, it is not associated with better retroperitoneal resection margin or retrieval of more positive LNs, and it does not lead to better curability or OS survival compared to DPS. Lack of adjuvant CRT and resection margin status are poor prognostic factors in patients with pancreas body and tail cancer.

Intraductal papillary neoplasm of the bile ducts: description of MRI and added value of diffusion-weighted MRI

PurposeTo evaluate MRI features of intraductal papillary neoplasm of the bile duct (IPNB) and to determine added value of diffusion-weighted MRI (DWI).MethodsTwenty-three patients with surgically confirmed invasive (nxa0=xa012) and non-invasive (nxa0=xa011) IPNB, who underwent preoperative liver MRI were included. Two observers performed consensus review of gadoxetic acid-enhanced MRI and combined gadoxetic acid-enhanced MRI including DWI separately, with regard to conspicuity of intraductal tumor using five point scales, extent of tumors, and the presence of invasiveness.ResultsOn MRI, there was no significant difference in the conspicuity of intraductal tumors between gadoxetic acid MRI (mean, 4.35) and combined MRI (mean, 4.65) (Pxa0=xa00.09). However, addition of DWI led seven cases revealed excellent conspicuity as compared with good or moderate conspicuity on gadoxetic acid MRI. With regard to invasiveness, 11 cases (48xa0%) and 17 (74xa0%) were correctly diagnosed with gadoxetic acid MRI and combined MRI, respectively (Pxa0=xa00.06). In invasive tumors, both of the two image sets did not help assess accurate extent of the tumor.ConclusionsThe addition of DWI to gadoxetic acid-enhanced MRI has a potency to improve conspicuity for intraductal tumors of IPNB and is helpful in determining tumor invasiveness, but not tumor extent.

Intraductal papillary neoplasms and mucinous cystic neoplasms of the hepatobiliary system: demographic differences between Asian and Western populations, and comparison with pancreatic counterparts

To improve the characterization of intraductal papillary neoplasm of the bile duct (IPNB) and mucinous cystic neoplasm of the liver (MCN‐L).