Conditional Relative Survival of Exocrine Pancreatic Cancer: A Population-Based Study.

BACKGROUND: Adjusted prognostic information is important for treatment decisions, especially in elderly patients or survivors of exocrine pancreatic cancer (EPC). This study aims to investigate conditional relative survival (CS) rates and conditional probabilities of death in patients with EPC. METHODS: Data of 77,975 individuals diagnosed with EPC between 1999 and 2019 were obtained from the Korea Central Cancer Registry. CS was analyzed across strata including histology groups (ductal adenocarcinoma excluding cystic or mucinous [group I, PDAC] and ductal adenocarcinoma specified as mucinous or cystic adenocarcinoma [group II]), and age. RESULTS: For PDAC, the overall 5-year relative survival (RS) rate at diagnosis, 3-year CS of 2-year survivors, and 5-year CS of 5-year survivors were 8.5%, 50.1%, and 77.6%, respectively. Overall conditional probabilities of death were 85.2% (≥ 80 years), 73.5% (70-79 years), and 62.0% (60-69 years) in year 1 after diagnosis. Among patients with localized or regional stage who underwent surgery, conditional probabilities of death of ≥ 80, 70-79, and 60-69 years were 37.7%, 32.5%, and 22.6% in the first year, and 26.6%, 27.2%, and 26.0% in year 2 after diagnosis. CONCLUSIONS: Half of patients with EPC who survived for 2 years survived for an additional 3 years. However, 5-year PDAC survivors require follow-up as more than 20% do not survive for a further 5 years. Elderly patients should not be excluded from active treatment for localized or regional-stage PDAC, as the CS of elderly patients who are fit enough to undergo surgery is not inferior to that of younger patients.

The need for hands-on training and supervision for entry-level physicians in a country with low surgical staffing density: a nationwide survey in Ghana.

BACKGROUND: Despite the largely unmet need, relatively few medical school graduates enrol in surgical residency and fewer surgical specialists work rurally in low- and middle-income countries. Surgical housemanship is the only formal training for medical graduates who will become the main surgical care providers in underserved areas. This study aimed to evaluate Ghanaian surgical housemanship (internship) and its impact on independent medical practice. METHODS: A nationwide questionnaire survey of surgical trainees from seven teaching or regional-level hospitals ascertained the experience and self-confidence levels for 35 training objectives set by the Medical and Dental Council of Ghana, and suggestions to improve surgical training quality. RESULTS: Of 310 respondents, 59.7% experienced ≤ 10 cases for each topic, and 24.8% reported self-confidence as ≤ 2 points (out of 5). More than 90% of respondents experienced ≤ 10 cases for gastric, colorectal and liver cancer management. Teaching hospital trainees had lower proportions of those experiencing > 10 cases (36.6% versus 43.7%) and reporting self-confidence ≥ 4 (46.5% versus 55.8%), respectively, compared with those from regional/other-level hospitals. 40% of respondents were not confident about their surgical skills, and 70.5% requested better-supervised and practical surgical skills training. The proportion of respondents who reported limited supervision was higher among those from teaching hospitals, reported self-confidence scores < 4, and experienced ≤ 10 cases for each topic. 67% of respondents were satisfied with their surgical housemanship and 75.8% perceived surgical rotation as relevant to their future work. CONCLUSIONS: Most surgical trainees are concerned about their surgical skills. A structured curriculum with specific goals and better-supervised surgical skills training should be established. Inclusion of regional/other-level hospitals in surgical training may reduce the supervisory burden in teaching hospitals.

Trend Analysis and Prediction of Hepatobiliary Pancreatic Cancer Incidence and Mortality in Korea.

BACKGROUND: This study aimed to analyze the current trends and predict the epidemiologic features of hepatobiliary and pancreatic (HBP) cancers according to the Korea Central Cancer Registry to provide insights into health policy. METHODS: Incidence data from 1999 to 2017 and mortality data from 2002 to 2018 were obtained from the Korea National Cancer Incidence Database and Statistics Korea, respectively. The future incidence rate from 2018 to 2040 and mortality rate from 2019 to 2040 of each HBP cancer were predicted using an age-period-cohort model. All analyses, including incidence and mortality, were stratified by sex. RESULTS: From 1999 to 2017, the age-standardized incidence rate (ASIR) of HBP cancers per 100,000 population had changed (liver, 25.8 to 13.5; gallbladder [GB], 2.9 to 2.6; bile ducts, 5.1 to 5.9; ampulla of Vater [AoV], 0.9 to 0.9; and pancreatic, 5.6 to 7.3). The age-standardized mortality rate (ASMR) per 100,000 population from 2002 to 2018 of each cancer had declined, excluding pancreatic cancer (5.5 to 5.6). The predicted ASIR of pancreatic cancer per 100,000 population from 2018 to 2040 increased (7.5 to 8.2), but that of other cancers decreased. Furthermore, the predicted ASMR per 100,000 population from 2019 to 2040 decreased in all types of cancers: liver (6.5 to 3.2), GB (1.4 to 0.9), bile ducts (4.3 to 2.9), AoV (0.3 to 0.2), and pancreas (5.4 to 4.7). However, in terms of sex, the predicted ASMR of pancreatic cancer per 100,000 population in females increased (3.8 to 4.9). CONCLUSION: The annual incidence and mortality cases of HBP cancers are generally predicted to increase. Especially, pancreatic cancer has an increasing incidence and will be the leading cause of cancer-related death among HBP cancers.

Self-reported confidence and perceived training needs of surgical interns at a regional hospital in Ghana: a questionnaire survey.

BACKGROUND: Due to disparities in their regional distribution of the surgical specialists, those who have finished "housemanship," which is the equivalent of an internship, are serving as main surgical care providers in rural areas in Ghana. However, the quantitative volume of postgraduate surgical training experience and the level of self-reported confidence after formal training have not been investigated in detail in sub-Saharan Africa. METHODS: The quality-assessment data of the Department of surgery at a regional hospital in Ghana was obtained from the convenience samples of house officers (HOs) who had their surgical rotation before July 2019. A self-reported questionnaire with 5-point Likert-type scale and open-ended responses regarding the 35 topics listed as learning objectives by the Medical and Dental Council of Ghana were retrospectively reviewed to investigate the volume of surgical experience, self-reported confidence, and perceived training needs. RESULTS: Among 52 respondents, the median self-reported number of patients experienced for each condition was less than 11 cases. More than 40% of HOs reported that they had never experienced cases of liver tumor (n = 21, 40.4%), portal hypertension (n = 23, 44.2%), or cancer chemotherapy/cancer therapy (n = 26, 50.0%). The median self-confidence score was 3.69 (interquartile range, 3.04 ~ 4.08). More than 50% of HOs scored ≤2 points on the self-confidence scale of gastric cancer (n = 28, 53.8%), colorectal cancer (n = 31, 59.6%), liver tumors (n = 32, 61.5%), and cancer chemotherapy/cancer therapy (n = 38, 73.1%). The top 3 reasons for not feeling confident were the limited number of patients (n = 42, 80.8%), resources and infrastructure (n = 21, 40.4%), and amount of supervision (n = 18, 34.6%). Eighteen HOs (34.6%) rated their confidence in their surgical skills as ≤2 points. Of all respondents, 76.9% (n = 40) were satisfied with their surgical rotation and 84.6% (n = 44) perceived the surgical rotation as relevant to their future work. Improved basic surgical skills training (n = 27, 51.9%) and improved supervision (n = 18, 34.6%) were suggested as a means to improve surgical rotation. CONCLUSIONS: Surgical rotation during housemanship (internship) should be improved in terms of cancer treatment, surgical skills, and supervision to improve the quality of training, which is closely related to the quality of surgical care in rural areas.

Clinical significance of defining borderline resectable pancreatic cancer.

Since the introduction of the concept of borderline resectable pancreatic cancer (BRPC), various definitions of this disease entity have been suggested. However, there are several obstacles in defining this disease category. The current diagnostic criteria of BRPC mainly focuses on its expanded 'technical resectability'; however, they are difficult to interpret because of their ambiguity using potential subjective or arbitrary terminology, In addition, limitations in current imaging technology and a lack of evidence in radiological-pathological-clinical correlation make it difficult to refine the criteria. On the other hand, neoadjuvant treatment is usually applied to increase the R0 resection rate of BRPC focusing on the 'oncological curability'. However, evidence is needed concerning the effect of neoadjuvant treatment by quality-controlled prospective randomized clinical trials based on a standardized radiologic and pathologic reporting system. In conclusion, there are two aspects in the current concept of BRPC, which are technical resectability and oncological curability. Although the recent evolution of surgical techniques is expanding the scope of technical resectability, it should not be overlooked that the disease entity must be defined based on the evidence of oncological curability.

Prediction of Pancreatic Fistula After Distal Pancreatectomy Based on Cross-Sectional Images.

BACKGROUND: Postoperative pancreatic fistula (POPF) is one of the most common and clinically relevant complications after distal pancreatectomy (DP), occurring in 5-40% of patients. Determining risk factors for this complication may aid in its prevention. This study sought to predict the development of POPF after DP preoperatively and objectively based on radiologic findings. METHODS: This study included 60 patients who underwent DP using a stapler for pancreatic division between June 2011 and January 2013. Fatty infiltration, apparent diffusion coefficients (ADC) on preoperative MRI, pathologic fat, and fibrosis were measured. Pancreatic thickness and cross-sectional area of the pancreas stump on CT scan were also measured. RESULTS: Mean patient age was 60.5 years, 26 patients (46.3%) had pancreatic cancer and 20 (33.3%) underwent laparoscopic surgery. Clinically relevant POPF was observed in 12 patients (20.0%). Linear regression analysis showed a significant correlation between fat quantification on MRI and pathologic fat (pathologic fat = 1.978 × MR fat -6.393, p < 0.001, R 2 = 0.777). Univariate analysis showed that ≤8% fat on MRI (p = 0.040), ≤5% pathologic fat (p = 0.002), ADC ≤ 1.3 × 10-3 mm2/s (p = 0.020), thicker pancreas (p = 0.007), and wider cross-sectional area of the pancreas (p = 0.013) were significantly associated with clinically relevant POPF after DP. Multivariate analysis revealed that pancreas thickness >17.6 mm [odds ratio (OR) 6.532, p = 0.064] and cross-sectional area >377 mm2 (OR 12.676, p = 0.052) were marginally related to clinically relevant POPF. CONCLUSIONS: Pancreatic thickness and cross-sectional area of the transected surface of the pancreas are marginally significant risk factors for POPF development after DP. Measuring pancreatic thickness and cross-sectional area can be a promising tool for the preoperative prediction of POPF.

Pancreatic Steatosis and Fibrosis: Quantitative Assessment with Preoperative Multiparametric MR Imaging.

PURPOSE: To evaluate the diagnostic performance of multiparametric pancreatic magnetic resonance (MR) imaging, including the T2*-corrected Dixon technique and intravoxel incoherent motion (IVIM) diffusion-weighted (DW) imaging, in the quantification of pancreatic steatosis and fibrosis, with histologic analysis as the reference standard, and to determine the relationship between MR parameters and postoperative pancreatic fistula. MATERIALS AND METHODS: This retrospective study was approved by the institutional review board, and the informed consent requirement was waived. A total of 165 patients (93 men, 72 women; mean age, 62 years) underwent preoperative 3-T MR imaging and subsequent pancreatectomy (interval, 0-77 days). Fat fractions, IVIM DW imaging parameters (true diffusion coefficient [D], pseudodiffusion coefficient [D*], and perfusion fraction [f]), pancreas-to-muscle signal intensity ratios on unenhanced T1-weighted images, and pancreatic duct sizes were compared with the fat fractions and fibrosis degrees (F0-F3) of specimens. In 95 patients who underwent pancreatoenteric anastomosis, MR parameters were compared between groups with clinically relevant postoperative pancreatic fistula and those without. The relationship between postoperative pancreatic fistula and MR parameters was evaluated by using logistic regression analysis. RESULTS: Fat fractions at MR imaging showed a moderate relationship with histologic findings (r = 0.71; 95% confidence interval: 0.63, 0.78). Patients with advanced fibrosis (F2-F3) had lower D*([39.72 ± 13.64] ×10(-3)mm(2)/sec vs [32.50 ± 13.09] ×10(-3)mm(2)/sec [mean ± standard deviation], P = .004), f (29.77% ± 8.51 vs 20.82% ± 8.66, P < .001), and unenhanced T1-weighted signal intensity ratio (1.43 ± 0.26 vs 1.21 ± 0.30, P < .001) than did patients with F0-F1 disease. Clinically relevant fistula developed in 14 (15%) of 95 patients, and f was significantly associated with postoperative pancreatic fistula (odds ratio, 1.17; 95% confidence interval: 1.05, 1.30). CONCLUSION: Multiparametric MR imaging of the pancreas, including imaging with the T2*-corrected Dixon technique and IVIM DW imaging, may yield quantitative information regarding pancreatic steatosis and fibrosis, and f was shown to be significantly associated with postoperative pancreatic fistulas.

Metabolic effect of pancreatoduodenectomy: Resolution of diabetes mellitus after surgery.

BACKGROUND: It is considered natural that glucose tolerance worsens after pancreatectomy. However, diabetes mellitus (DM) resolves after metabolic bypass surgery and anatomic changes after PD resemble those after metabolic surgery. This study assessed the incidence of DM resolution after pancreatectomy and differences in metabolic parameters following pancreatoduodenectomy (PD) and distal pancreatectomy (DP). METHODS: Between 2007 and 2013, 218 consecutive patients with pancreatic diseases underwent PD (n = 112) or DP (n = 106) at Seoul National University Hospital. Factors associated with changes in glucose homeostasis were evaluated by assaying serum glucose concentrations in prospectively collected samples. RESULTS: Of the 218 patients, 88 (40.4%) had preoperative DM, with 27 (30.7%) of the latter showing postoperative resolution of DM, a rate significantly higher in patients who had undergone PD than DP (40.4% vs. 12.9%, p = 0.008). Fasting blood glucose (p = 0.001), PP2 (p < 0.001), and HOMA-IR (p = 0.005) significantly decreased after PD but not after DP. Multivariate analysis revealed that PD was independently associated with DM resolution (odds ratio 7.790, p = 0.003). PD was associated with a significantly higher DM resolution rate than DP among the 37 pancreatic cancer patients with preoperative DM (34.6% vs. 0%, p = 0.036). DM resolution rates were similar in pancreatic cancer and other pancreatic diseases (p = 0.419). CONCLUSION: More than 40% of patients with preoperative DM show resolution after PD. Decreased insulin resistance and suspected enhanced glucose stimulated insulin secretion decreasing PP2 seem to contribute improved glucose homeostasis after PD. BMI was unrelated to DM resolution, indicating that PD-associated physio-anatomical changes may help resolve DM independent of weight.

Molecular subtypes of pancreatic cancer based on miRNA expression profiles have independent prognostic value.

BACKGROUND AND AIM: Altered microRNAs (miRNA) expression, a typical feature of many cancers, is reportedly associated with prognosis according to several studies. Although numerous studies on miRNAs in pancreatic ductal adenocarcinoma have also attempted to identify prognostic biomarkers, more large-scale clinical studies are needed to establish the clinical significance of the results. Present study aimed to identify prognosis-related molecular subtypes of primary pancreas tumors using miRNA expression profiling. METHODS: Expression profiles of 1733 miRNAs were obtained by using microarray analysis of 104 pancreatic tumors of Korean patients. To detect subgroups informative in predicting the patient's prognosis, we applied unsupervised clustering methods and then analyzed the association of the molecular subgroups with survival time. Then, we constructed a classifier to predict the subgroup using penalized regression models. RESULTS: We have determined three pancreatic ductal adenocarcinoma tumor subtypes associated with prognosis based on miRNA expression profiles. These subtypes showed significantly different survival time for patients with the same clinical conditions. This demonstrates that our prognostic molecular subgroup has independent prognostic utility. The molecular subtypes can be predicted with a classifier of 19 miRNAs. Of the 19 signature miRNAs, miR-106b-star, miR-324-3p, and miR-615 were related to a p53 canonical pathway, and miR-324, miR-145-5p, miR-26b-5p, and miR-574-3p were related to a Cox-2 centered pathway. CONCLUSIONS: Our prognostic molecular subtypes demonstrated that miRNA profiles could be used as prognostic markers. Additionally, we have constructed a classifier that may be used to determine the molecular subgroup of new patient sample data. Further studies are needed for validation.

Comparison of laparoscopic versus open left-sided hepatectomy for intrahepatic duct stones.

BACKGROUND: Laparoscopic hepatectomy for intrahepatic duct (IHD) stones is limited by technical difficulties caused by adhesion to adjacent tissue or distorted anatomy resulting from recurrent inflammation. This study compared perioperative and clinical outcomes in patients undergoing laparoscopic and open hepatectomy for left IHD stones. METHODS: From January 2002 to December 2013, 40 patients underwent laparoscopic left-sided hepatectomy [left hemihepatectomy (n = 7) or left lateral sectionectomy (n = 33)] and 54 patients without combined operations and previous operation histories underwent open left-sided hepatectomy [left hemihepatectomy (n = 24) or left lateral sectionectomy (n = 30)]. Their perioperative and clinical outcomes were compared, including stone clearance rates, stone recurrence rates, and median follow-up duration. RESULTS: There was no difference in age (56.8 ± 8.2 vs. 55.6 ± 9.6 years, p = 0.531), sex (1.0:4.0 vs. 1.0:1.8 male:female, p = 0.108), or BMI (22.8 ± 2.8 vs. 22.9 ± 3.0 kg/m(2), p = 0.802) between the laparoscopic and open hepatectomy groups. Lateral sectionectomy was more frequent in the laparoscopic group (33/40 vs. 30/54, p = 0.010). Operation time (174.2 ± 56.6 vs. 210.4 ± 51.6 min, p = 0.002) and postoperative hospital stay (7.9 ± 2.6 vs. 14.3 ± 5.5 days, p < 0.001) were shorter in the laparoscopic group, and complication rate (17.5 vs. 40.7%, p = 0.016), in particular surgical site infection rate (5.0 vs. 18.5%, p = 0.052), was lower in the laparoscopic group than in the open hepatectomy group. Similar results were observed in the hemihepatectomy and lateral sectionectomy subgroups. There was no operation-related mortality. There were no significant differences in follow-up periods (48 ± 33.6 vs. 59.2 ± 41.7 months, p = 0.235) and rates of initial stone clearance (87.5 vs. 75.9%, p = 0.159), final clearance (100 vs. 94.4%, p = 0.130), and stone recurrence (2.5 vs. 5.6%, p = 0.468). CONCLUSION: Laparoscopic hepatectomy is safe and effective for well-selected patients with left IHD stones, when performed by experienced surgeons. Laparoscopic hepatectomy resulted in shorter operation time and postoperative hospital stay, and a lower postoperative morbidity rate, than open hepatectomy.

Clinicopathologic Differences in Patients with Gallbladder Cancer According to the Presence of Anomalous Biliopancreatic Junction.

BACKGROUND: Anomalous biliopancreatic junction (ABPJ) is a risk factor for gallbladder cancer (GBC). This study investigated the significance of ABPJ in patients with GBC. METHODS: Of the 453 patients with GBC underwent surgery at Seoul National University Hospital between 2000 and 2014, the 401 patients who can be assessed for the presence of ABPJ with radiologic image were analyzed. RESULTS: The 401 patients with GBC included 183 (45.6 %) males and 218 (54.4 %) females. ABPJ was identified in 69 (17.2 %) patients, 22 (31.9 %) males and 47 (68.1 %) females. Choledochal cyst (CC) was identified in 18 (4.5 %) patients, all of whom had ABPJ. Curative surgery was accomplished in 68.1 %. A comparison of patients with and without ABPJ showed that mean age (59.9 vs. 65.1 years, p < 0.001) and association with gallbladder stone (8.7 vs. 24.7 %, p = 0.002) were significantly lower in the ABPJ group, while the proportion of female (68.1 vs. 51.5 %, p = 0.012), bile duct resection rate (47.8 vs. 18.4 %, p < 0.001), and curative resection rate (81.1 vs. 65.7 %, p = 0.003) were significantly higher in the ABPJ group. Overall 5-year survival rates were similar in the ABPJ and non-ABPJ groups (74.4 vs. 69.0 %, p = 0.533). In patients with ABPJ, the presence of CC did not have a significant effect on survival (p = 0.099). CONCLUSIONS: ABPJ was found in 17.2 % of patients with GBC. ABPJ is associated with younger age, female gender, absence of gallbladder stones, higher BDR rate, and higher curative resection rate. However, neither ABPJ nor CC was prognostic of survival in curatively treated patients with GBC.

Endocrine Function Impairment After Distal Pancreatectomy: Incidence and Related Factors.

BACKGROUND AND AIM: Little is known about the incidence of and risk factors for glucose intolerance after distal pancreatectomy. This study investigated the clinicopathologic factors associated with the development of glucose intolerance or overt diabetes mellitus (DM) after distal pancreatectomy, and the correlation between resected pancreas volume and endocrine function impairment. METHODS: After excluding patients with preoperative DM, 101 patients who underwent distal pancreatectomy with a minimum of 1-year postoperative follow-up were enrolled in this prospective cohort. Patients were assessed preoperatively and 1 week and 12 months postoperatively by oral glucose tolerance tests and by measures of HbA1c and pancreatic volume. RESULTS: Mean patient age was 54.1 years, mean body mass index (BMI) was 23.3 kg/m(2), and the male-to-female ratio was 1:1.8. Of the 101 patients, 21 (20.8 %) had pancreatic ductal adenocarcinoma. The median percent resected pancreas volume was 28.0 % (range 5.0-71.3 %). One year after distal pancreatectomy, 51 patients (50.5 %) had glucose intolerance, including 26 with impaired fasting glucose and 25 with DM. ROC curve analysis showed that a resected pancreas volume of 25 % showed maximum diagnostic value for development of glucose intolerance. Univariate analysis showed that female sex (58.5 vs. 36.1 %, P = 0.031), BMI (24.1 vs. 22.5 kg/m(2), P = 0.010), larger resected volume (36.5 vs. 28.0 %, P = 0.026), and lower remnant volume relative to BMI (1.7 × 10(-3) vs. 2.1 × 10(-3) m(5)/kg, P = 0.021) were risk factors for postoperative endocrine function impairment. Multivariate analysis revealed that female sex (odds ratio [OR] 5.818, P = 0.003), higher BMI (OR 10.556, P = 0.006), and resected pancreatic volume (OR 3.192, P = 0.035) were independent risk factors for endocrine impairment. CONCLUSIONS: About 50 % of patients without preoperative DM developed impaired glucose tolerance or overt DM following distal pancreatectomy. Female sex, higher BMI, and resection of pancreatic volume >25 % were risk factors for endocrine function impairment, indicating the need for preoperative evaluation and careful perioperative glucose monitoring in these patients.

Actual Long-Term Survival Outcome of 403 Consecutive Patients with Hilar Cholangiocarcinoma.

BACKGROUND: Despite aggressive surgical resection, prognosis of patients with hilar cholangiocarcinoma is still unsatisfactory. There were limited data about actual long-term survival outcome. This study was designed to explore actual long-term survival outcome of hilar cholangiocarcinoma after surgical treatment, and to investigate the characteristics of patients with actual long-term survival. METHODS: The study cohort consisted of 403 consecutive patients with at least 5-year follow-up after surgical treatment for hilar cholangiocarcinoma at Seoul National University Hospital between 1991 and 2010. Prognostic factors were analyzed with Cox proportional hazard models, and the effect of adjuvant treatment was evaluated by propensity score analysis. RESULTS: Of all patients, R0 resection rate was 41.2 and 63.8 % among intended curative resection. Adjuvant therapy was performed in 48.8 % after curative surgery. Actual 5-year overall survival (OS) rate was 18.9, and 30.1 % after R0 resection. Actual 5-year disease-free survival rate was 25.8 % after resection. Adjuvant treatment improved prognosis in patients with positive metastatic lymph nodes (median OS 21.9 vs. 11.5 months, p = 0.003). Overall recurrence rate was 55.0 %, and distant metastasis (39.7 %) was more frequent than loco-regional recurrence (20.8 %). Lymph node metastasis (p = 0.021) and poor histologic grade (p < 0.001) were independent prognostic factors after curative resection. Patients who survived more than 5 years had less lymph node metastasis (p = 0.025), poor histologic differentiation (p = 0.010), R2 resection (p = 0.040), and recurrence (p < 0.001). CONCLUSION: Actual 5-year OS rate after R0 resection of hilar cholangiocarcinoma is 30.1 %. Adjuvant treatment could be beneficial in patients with lymph node metastasis.

The clinical usefulness of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in follow-up of curatively resected pancreatic cancer patients.

BACKGROUND: Computed tomography and serum tumor markers have limited value in detecting recurrence after curative surgery of pancreatic cancer. This study evaluated the clinical utility of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT) in diagnosing recurrence. METHODS: One hundred ten patients underwent curative resection of pancreatic cancer were enrolled. The diagnostic value of abdominal computed tomography (CT), PET-CT and serum carbohydrate antigen (CA) 19-9 concentration were compared. The prognostic value of SUVmax on PET-CT was evaluated. RESULTS: PET-CT showed relatively higher sensitivity (84.5% vs. 75.0%) and accuracy (84.5% vs. 74.5%) than CT, whereas PET-CT plus CT showed greater sensitivity (97.6%) and accuracy (90.0%) than either alone. In detecting distant recurrences, PET-CT showed higher sensitivity (83.1% vs. 67.7%) than CT. Nineteen patients showed recurrences only on PET-CT, with eleven having invisible or suspected benign lesions on CT, and eight had recurrences in areas not covered by CT. SUVmax over 3.3 was predictive of poor survival after recurrence. CONCLUSIONS: PET-CT in combination with CT improves the detection of recurrence. PET-CT was especially advantageous in detecting recurrences in areas not covered by CT. If active post-operative surveillance after curative resection of pancreatic cancer is deemed beneficial, then it should include PET-CT combined with CT.

Clinicopathological Meaning of Size of Main-Duct Dilatation in Intraductal Papillary Mucinous Neoplasm of Pancreas: Proposal of a Simplified Morphological Classification Based on the Investigation on the Size of Main Pancreatic Duct.

BACKGROUND: The 2012 consensus guideline on intraductal papillary mucinous neoplasm of the pancreas (IPMN) described a three-stage criteria involving main pancreatic duct (MPD) size with definitions of malignancy relevant for treatment decisions. Re-evaluation and simplification of this classification for clinicians are warranted. METHODS: Data from the Seoul National University Hospital of 375 consecutive patients with pathology-confirmed IPMN after surgery were analyzed. The association between clinicopathologic characteristics of IPMN and MPD size was assessed. The cut-off value of MPD size for a current definition of malignancy prediction was calculated. RESULTS: Diagnostic accuracy for malignancy was highest when the cut-off value of MPD size was 7 mm (area under the curve=0.7126). Dichotomizing IPMN into MPD≤7 mm versus MPD> mm, patient age (p=0.039), sex (p=0.001), presence of mural nodule (p<0.001), and invasiveness risk (13.2 vs. 39.8%, p<0.001) resulted in significantly different results. Mural nodule-negative patients with MPD>7 mm had a significantly lower 5-year survival rate than those with MPD≤7 mm (78.4 vs. 91.4%, p=0.006). Among patients with MPD size≤7 mm, elevated serum CA 19-9 and mural nodule were independent risk factors of malignancy. Patients with MPD size≤7 mm without these risk factors had malignancy risk of 2.6%. CONCLUSION: Using the definition of malignancy provided in the 2012 guideline, the MPD size> mm criterion was statistically driven. The current morphologic classification of IPMN can be simplified as branch-duct-predominant IPMN (MPD≤7 mm)' and main-duct-predominant IPMN (MPD> mm). Patients who are determined to have main-duct-predominant IPMN and branch-duct-predominant IPMN with elevated serum CA 19-9 or mural nodule are recommended to undergo surgical treatment.

Clinicopathologic analysis of gastrointestinal stromal tumors in duodenum and small intestine.

BACKGROUND: The prognosis about duodenal GISTs is debatable. The purpose of this study is to compare the characteristics and the prognostic factors in patients with gastrointestinal stromal tumor (GIST) located in the duodenum with those located in the small intestine. METHODS: One hundred-one patients with GIST located in the duodenum (n = 40), or small intestine (n = 61) underwent resection between 1996 and 2010. We analyzed clinicopathologic features, surgical outcomes, and prognostic factors. RESULTS: Five-year survival rate in patients with GIST located in the duodenum and small intestine were 66.6 and 80.8%, respectively (p = 0.018). After survival analysis, high mitotic count and tumor rupture were identified as independent adverse prognostic factors. Advanced T stage and absence of adjuvant imatinib treatment were adverse prognostic factors with marginal statistical significance. The rate of progressive disease was significantly higher in patients with duodenal GISTs (36.8%) than in those with small intestinal GIST (29.6%) (p = 0.024). CONCLUSIONS: The clinicopathologic findings of duodenal GIST differ from those of small intestinal GIST. Patients with duodenal GIST have a worse prognosis than those with small intestinal GIST. Aggressive treatment including surgical resection should be considered for duodenal GIST, even if the risk is relatively low.

Long-term prospective cohort study of patients undergoing pancreatectomy for intraductal papillary mucinous neoplasm of the pancreas: implications for postoperative surveillance.

OBJECTIVE: To evaluate long-term follow-up results after surgical treatment of intraductal papillary mucinous neoplasm (IPMN) to optimize postoperative surveillance strategies. BACKGROUND: Little is known about the postoperative natural history of IPMN, especially about long-term follow-up results in patients with benign or noninvasive IPMN. METHODS: Long-term follow-up was undertaken in a prospective cohort of 403 consecutive patients who underwent surgical treatment of IPMN at Seoul National University Hospital. Of these, 37 patients with ductal adenocarcinoma arising in IPMN were excluded from the analysis. RESULTS: Of the 366 patients, 82 had low-grade dysplasia, 171 had intermediate-grade dysplasia, 45 had high-grade dysplasia, and 68 had IPMN with associated invasive carcinoma. During a median follow-up of 44.4 months, the overall recurrence rate was 10.7%. Pathologic grade of dysplasia was associated with recurrence rate (P < 0.001). IPMNs involving main duct had higher rate of recurrence (P = 0.021). Of the 298 patients with benign or noninvasive IPMN, 16 (5.4%) had recurrences including distant metastasis. Multivariate analysis revealed that the degree of dysplasia was the most important predictor of recurrence (P < 0.001). The overall 5-year disease-free survival rate was 78.9% and was significantly lower in patients with high-grade dysplasia than in those with low- or intermediate-grade dysplasia (P = 0.045). CONCLUSIONS: Pancreatic IPMNs recur in 10.7% of patients. Recurrence is correlated with the degree of dysplasia, and 5.4% of patients with benign or noninvasive IPMN have recurrences including distant metastasis. Thorough postoperative surveillance is needed not only for patients with invasive IPMN but also for those with benign or noninvasive IPMN, especially for patients with high-grade dysplasia.

A prospective randomized controlled study comparing outcomes of standard resection and extended resection, including dissection of the nerve plexus and various lymph nodes, in patients with pancreatic head cancer.

OBJECTIVE: To prospectively evaluate the survival benefit of dissection of the nerve plexus and lymphadenectomy in patients with pancreatic head cancer. BACKGROUND: Despite randomized controlled trials on the extent of surgery in pancreatic cancer, attempts have been made to perform more extended resections. METHODS: A total of 244 patients were enrolled; of these, 200 were randomized to undergo standard resection or extended resection, with the latter including the dissection of additional lymph nodes and the right half of the nerve plexus around the superior mesenteric artery and celiac axis. We evaluated 167 patients from 7 centers who fulfilled all of the required criteria. RESULT: Operation time was longer and estimated blood loss was higher in the extended resection group than in the standard resection group, but the R0 resection rate was comparable. The mean number of lymph nodes retrieved per patient was higher in the extended resection group than in the standard resection group (33.7 vs 17.3; P < 0.001). The morbidity rate was slightly higher in the extended resection group than in the standard resection group. Two patients in the extended resection group died in hospital. Median survival after R0 resection was similar in the extended resection and standard resection groups (18.0 vs 19.0 months; P = 0.239) regardless of lymph node metastasis. Adjuvant chemoradiation had a positive impact on overall survival. CONCLUSIONS: This study suggests that extended lymphadenectomy with dissection of the nerve plexus does not provide a significant survival benefit compared with standard resection in pancreatic head cancer. Standard resection can be performed safely and efficiently, without negatively affecting oncologic efficacy or long-term survival, when compared with extended pancreaticoduodenal resection. (NCT00679913)?

Revisiting the concept of lymph node metastases of pancreatic head cancer: number of metastatic lymph nodes and lymph node ratio according to N stage.

BACKGROUND: Some suggest that metastatic lymph node ratio (LNR) may be prognostic of survival in patients with pancreatic cancer. However, this phenomenon was confused by inclusion of node-negative patients in the analysis. The present study was designed to evaluate the prognostic impact of metastatic LNR and the absolute number of metastatic LNs in patients resected for pancreatic cancer. METHODS: Data were collected from 398 patients who underwent curative surgery for pancreatic head cancer at Seoul National University Hospital. Long-term survival was analyzed according to LNR and absolute number of metastatic LNs. RESULTS: Of the patients, 227 (57.0 %) had LN metastasis. The mean numbers of total retrieved and metastatic LNs were 19.5 and 1.9, respectively, and the mean LNR was 0.11. Median overall survival (OS) of patients was significantly higher in N0 than in N1 patients after curative resection (25.4 vs. 14.8 months, p < 0.001). Median OS was significantly lower in patients with 1 than in those with 0 positive LNs (17.3 vs. 25.4 months, p = 0.001). Among N1 patients, those with 0 < LNR ≤ 0.2 had comparable prognosis than those with >0.2 LNR (median OS 17.2 vs. 12.8 months, p = 0.096), and the number of metastatic LNs did not correlate with median OS (p = 0.365). CONCLUSIONS: The presence of a single positive metastatic LN was associated with significantly poorer OS in patients with pancreatic cancer. When LN metastasis was present, the number of metastatic LNs and LNR had limited prognostic relevance.

Mucinous cystic neoplasm of the pancreas: is surgical resection recommended for all surgically fit patients?

BACKGROUND: Surgical removal of mucinous cystic neoplasms (MCNs) is usually recommended because of the risk of malignancy. However, increased experience of MCNs suggests that the incidence of invasion is lower than had been thought. This study was designed to establish more reasonable surgical indications for MCN through re-assessment using strict pathologic diagnostic criteria. METHODS: Ninety-four patients who underwent surgical removal of MCNs at Seoul National University Hospital from 1991 to 2012 were retrospectively analyzed. Pathologic results were re-evaluated by an experienced pathologist. Medical records and radiologic images were reviewed to determine factors predicting malignancy. RESULTS: Of the 94 patients, 4 were found to have intraductal papillary mucinous neoplasms (IPMNs). Of the 90 MCNs, 60 (66.7%) were low-grade, 21 (23.3%) were intermediate-grade, and 5 (5.5%) were high-grade dysplasias; and 4 (4.4%) were invasive carcinoma. Mural nodules on CT scan (p = 0.005) and abnormal serum CA19-9 concentration (p = 0.029) were significant predictors of malignancy. All MCNs less than 3 cm in size with normal serum tumor markers were benign and all malignant MCNs had cyst fluid CA19-9 over 10,000 units/ml. The five year disease specific survival rates were 98.8% for all patients and 75.0% for those with invasive MCNs. CONCLUSION: MCNs had a low prevalence of malignancy. Regardless of the histological grade, long-term outcome was excellent. Therefore, in the absence of specific symptoms, surgery may not be indicated for MCNs <3 cm without mural nodules or elevated serum tumor markers. Validation by a prospective study with very careful design is needed.