Toshihide Imaizumi

Pancreatic Cancer Registry in Japan: 20 years of experience.

Abstract: The prognosis of pancreatic cancer is defined by the histology and extent of disease. Preoperative histologic diagnosis and diagnostic imaging are fundamentals in managing the disease, but it is not rare to find unexpected peritoneal dissemination or liver metastasis at the time of operation. The overall resectability rate of pancreatic cancer is 40% in Japan. Resecting the portal vein and peripancreatic plexus were performed on 40% of the patients who underwent pancreatectomy for invasive cancer in the head of the pancreas. Long-term survival was only found in patients who underwent pancreatectomy. Radical lymph node dissection, or combined resection of the large vessels, did not seem to improve survival further than the standard resection. Multidisciplinary treatments combined with surgery were performed, and various effects of postoperative chemotherapy after pancreatectomy, intraoperative- and postoperative-radiation therapy, or postoperative chemotherapy for unresectable tumor, were shown. Development of unconventional therapies and refinement of the conventional therapy should be promoted on a randomized prospective trial basis. To promote this effort, which requires the international comparisons and cooperation, JPS developed a computerized JPS registration system downloadable from the JPS website (http://www.kojin.or.jp/suizou/index.html).

Surgery versus radiochemotherapy for resectable locally invasive pancreatic cancer: final results of a randomized multi-institutional trial.

PurposeAlthough the outcome of surgery for locally advanced pancreatic cancer remains poor, it is improving, with 5-year survival up to about 10% in Japan. The preliminary results of our multi-institutional randomized controlled trial revealed better survival after surgery than after radiochemotherapy. We report the final results of this study after 5 years of follow-up.MethodsPatients with preoperative findings of pancreatic cancer invading the pancreatic capsule without involvement of the superior mesenteric or common hepatic arteries, or distant metastasis, were included in this randomized controlled trial, with their consent. If the laparotomy findings were consistent with these criteria, the patient was randomized to a surgery group or a radiochemotherapy group (5-fluorouracil 200 mg/m2/day and 5040 Gy radiotherapy). We compared the mean survival time, 3-and 5-year survival rates, and hazard ratio.ResultsThe surgery and radiochemotherapy groups comprised 20 and 22 patients, respectively. Patients were followed up for 5 years or longer, or until an event occurred to preclude this. The surgery group had significantly better survival than the radiochemotherapy group (P < 0.03). Surgery increased the survival time and 3-year survival rate by an average of 11.8 months and 20%, respectively, and it halved the instantaneous mortality (hazard) rate.ConclusionLocally invasive pancreatic cancer without distant metastases or major arterial invasion is treated most effectively by surgical resection.

Clinical experience with duodenum‐preserving total resection of the head of the pancreas with pancreaticocholedochoduodenostomy

The results of duodenum-preserving total resection of the head of the pancreas (DpTRHP) in 20 patients were compared with the results of pylorus-preserving pancreatico-duodenostomy (PpPD), a procedure in conventional use for the treatment of benign diseases, in 19 patients. The mean operative time for DpTRHP was 4.5±0.9 h, this being not significantly different from that for PpPD, whereas the mean intraoperative blood loss with DpTRHP (825±508ml) was significantly less than that with PpPD (1382±798 ml) (P<0.05). The morbidity and mortality rates of patients treated with DpTRHP were 25% and 0%, respectively, and there were no significant differences between the two surgical treatment groups for these values. The outcome of treatment with DpTRHP was excellent, as was that of PpPD, in terms of the frequency of early gastric stasis, the duration of hospital stay, the patients capacity for taking food, gaining weight, and working, and the performance status 6 months postoperatively. Thus, DpTRHP, which entails the least extent of resection of the head of the pancreas compared to other currently employed procedures and enables the operator to accomplish reconstruction of the pancreatic and biliary systems without resecting or interrupting the continuity of the digestive tract, was not attended by any serious complications, while, digestive tract function was well preserved, and satisfactory results were produced.

Use of omentum or falciform ligament does not decrease complications after pancreaticoduodenectomy: Nationwide survey of the Japanese Society of Pancreatic Surgery

BACKGROUND Wrapping is thought to prevent pancreatic fistula and postoperative hemorrhage for pancreaticoduodenectomy (PD), and we analyzed whether omentum/falciform ligament wrapping decreases postoperative complications after PD. METHODS This is a retrospective study of wrapping using the omentum/falciform ligament in patients that underwent PD between January 2006 and June 2008 in 139 institutions that were members of the Japanese Society of Pancreatic Surgery. RESULTS Ninety-one institutions responded to the questionnaires, and data were accumulated from 3,288 patients. The data from 2,597 patients were acceptable for analysis; 918 (35.3%) patients underwent wrapping and 1,679 patients did not. A pancreatic fistula occurred in 623 patients (37.3%) in the nonwrapping group, in comparison to 393 patients (42.8%) in the wrapping group (P = .006). The incidence of a grade B/C pancreatic fistula was lower in the nonwrapping group than the wrapping group (16.7% vs. 21.5%; P = .002). An intra-abdominal hemorrhage occurred in 54 patients (3.2%) in the nonwrapping group, which was similar to the incidence in the wrapping group (32 patients; 3.5%). The mortality was 1.3% and 1.0% in nonwrapping and wrapping groups, respectively. A multivariate analysis revealed 7 independent risk factors for pancreatic fistula; male, hypoalbuminemia, soft pancreas, long operation time, extended resection, pylorus preservation, and omentum wrapping. There were 4 independent risk factors for early intra-abdominal hemorrhage and 2 independent risk factors for late intra-abdominal hemorrhage. CONCLUSION This retrospective study revealed that omentum wrapping did not decrease the incidence of pancreatic fistula. An additional validation study is necessary to evaluate the efficacy of wrapping for PD.

Stenting is unnecessary in duct-to-mucosa pancreaticojejunostomy even in the normal pancreas

Background: There is a high risk of anastomotic leakage after pancreaticojejunostomy after pancreaticoduodenectomy (PD) in patients with a normal pancreas because of the high degree of exocrine function. These PD are therefore generally performed using a stenting tube (stented method). In recent years, we have performed pancreaticojejunostomy with duct-to-mucosa anastomosis without a stenting tube (nonstented method) and obtained good results. Methods: The point of this technique is to preserve adequate patency of the pancreatic duct by carefully picking up the pancreatic duct wall with a fine atraumatic needle and monofilament thread. The results of end-to-side pancreaticojejunostomy of the normal pancreas were compared between the nonstented method (n = 109) and the stented method (n = 39). Results: There were no differences in background characteristics between the groups, including age, gender and disease. The mean duration to complete pancreaticojejunostomy was 26.6 min in the nonstented group and 29.2 min in the stented group. The mean durations of surgical procedure and intraoperative blood loss were also similar in the groups. Morbidity rates due to early postoperative complications were 20.2 and 23.1%, with pancreatic leakage occurring in 7.3 and 7.7% of patients, respectively. These differences were not statistically significant. One patient in the stented group died of sepsis following leakage of pancreaticojejunostomy. There were also no significant differences in the mean time to initiation of solid food intake or postoperative hospital stay. Conclusion: We conclude that a stenting tube is unnecessary if the duct-to-mucosa anastomosis is completely performed. This operative technique can be considered a basic procedure for pancreaticojejunostomy because of the low risk.

FDG-PET and diffusion-weighted MR imaging appearance in retroperitoneal Castleman's disease: a case report.

Castlemans disease is a rare lymphoid neoplasm that is characterized by the proliferation of lymphoid tissue. A case of young woman having the plasma cell type of retroperitoneal Castlemans disease is reported, and radiological findings of the condition are discussed with a review of the radiological literature.

Perivascular epithelioid cell tumor (PEComa) of the pancreas: Immunoelectron microscopy and review of the literature

A perivascular epithelioid tumor (PEComa) is a rare tumor probably arising from the perivascular epithelioid cells. Only three cases of pancreatic PEComa have been reported in the English‐language literature. The present report describes an extremely rare case of pancreatic PEComa. A 47‐year‐old Japanese woman complained of lower abdominal pain and a well‐demarcated solid tumor was found in the pancreatic head. There was no history of tuberous sclerosis complexes. Pylorus‐preserving pancreaticoduodenectomy was thus performed. There was a well‐demarcated, solid tumor measuring 17 mm in the pancreatic head. The tumor was composed of a diffuse proliferation of epithelioid tumor cells with many blood vessels but no adipose tissue. The tumor cells expressed HMB45 and α‐smooth muscle actin. Ultrastructurally, the tumor cells possessed many membrane‐bound granules that were positive for HMB45 on immunoelectron microscopy. The results of immunoelectron microscopy show that some PEComas possess not only typical melanosomes or premelanosomes but also aberrant melanosomes.

Clinical significance of wall invasion pattern of subserosa-invasive gallbladder carcinoma.

We have previously classified wall invasion patterns of gallbladder carcinoma (GBC) cases into two groups, i.e., the infiltrative growth type (IG type) and destructive growth type (DG type). The DG type was significantly associated with poor differentiation, aggressive infiltration and decreased postoperative survival in terms of its histological differentiation, lymphatic invasion, venous invasion, lymph node status, neural invasion and mode of subserosal infiltration. In the present study, we analyzed 42 surgically-resected subserosal invasive gallbladder adenocarcinomas, invading the perimuscular connective tissue (pT2). The cumulative 5-year survival rate in the series was 48.7%. Lymphatic invasion (p=0.021), venous invasion (p=0.020), mode of subserosal infiltration (p<0.001), histological differentiation (p=0.030) and biliary infiltration (p=0.007) were noted, respectively, at a significantly higher incidence in more aggressive infiltration or poor differentiation in the DG type. The cumulative 5-year survival rate of curative resection cases was lower in patients with the DG type than in those with the IG type (68.9 versus 20.2%, respectively, p=0.006, log-rank test). On Cox’s proportional hazard regression modeling, the low degree of venous/perineural invasion and IG type of wall invasion pattern were associated with a significant improvement in overall survival. Our data suggest that the wall invasion pattern is an independent predictor of survival in subserosal invasive GBC. Regarding the clinical application of our concept, on the classification of patients with subserosal invasive GBC based on a combination of the wall invasion pattern and lymph node status, the overall survival rate in patients with the DG type and/or N2 metastasis (n=21) was lower than in patients with the IG type and N0, 1 metastasis (n=21) (p=0.0023, log-rank test). The wall invasion pattern could contribute to decision-making concerning curative resection for subserosal invasive GBC.

Leiomyosarcoma of the pancreas: Report of a case

Leiomyosarcoma of the pancreas is a rare neoplasm, with only 34 reported cases in the literature. We encountered a rare case of leiomyosarcoma of the pancreas, treated successfully by surgery. A 41-year-old woman was referred to our hospital for further examinations of a pancreatic tumor. Imaging studies demonstrated a solid and lobular mass, about 4 cm in diameter, in the body of pancreas. This mass had a nonuniform content and was encapsulated. We performed distal pancreatectomy and splenectomy for an assumed diagnosis of invasive ductal carcinoma. Macroscopically, a sagittal section of the operative specimen showed a well-circumscribed yellowish-white mass without any cystic changes. Immunohistological examination revealed that α-smooth muscle actin, desmin, and vimentin were positive, and the labeling index of MIB-1 was 50% or more. Based on these findings, we confirmed a diagnosis of leiomyosarcoma originating from the pancreas. During 14 months of follow-up to date, there has not been any evidence of local recurrence or distant metastasis.

An annular pancreas associated with carcinoma of the papilla of Vater: report of a case

An annular pancreas is an uncommon congenital anomaly that usually presents early in childhood. Malignancy in the setting of an annular pancreas is unusual. We herein report a case of annular pancreas with carcinoma of the papilla of Vater. A 59-year-old man presented with epigastric discomfort and was referred to us after gastroduodenal endoscopy showed a tumor of the papilla of Vater. Preoperative imaging showed the pancreatic parenchyma encircling the descending duodenum and a tumor at the papilla of Vater. A pancreaticoduodenectomy was performed for the annular pancreas and the ampullary tumor. Histological examination confirmed a complete annular pancreas and carcinoma in situ of the papilla of Vater. We also provide a review of the reported cases of an annular pancreas with periampullary neoplasms and discuss the clinical characteristics of this anomaly.