Kunio Okajima

Usefulness of preoperative FDG-PET for detection of gastric cancer.

BackgroundPositron emission tomography (PET), using 18F-fluoro-2-deoxy-d-glucose (FDG) as a tracer, can detect malignant neoplasms with altered glucose metabolism. To clarify the usefulness of FDG-PET for detecting gastric cancer, we evaluated preoperative PET imaging in gastric cancer patients.MethodsSixty-two gastric cancer patients who underwent FDG-PET imaging and gastric resection with lymphadenectomy were evaluated.ResultsFor primary tumor assessment by PET, detection rates were significantly different in the following order: tumor size 30 mm or more (76.7%) > tumor size less than 30 mm (16.8%); advanced gastric cancer (AGC, 82.9%) > early gastric cancer (EGC; 25.9%); with nodal involvement (79.3%) > without nodal involvement (39.4%). In EGCs, the detection rate of the intestinal type, according to Laurens classification (43.8%) was significantly higher than that of the diffuse type (0%). Two of the 7 EGC patients who were PET-positive had nodal involvement and their tumors were the intestinal type. For the assessment of nodal involvement, the accuracy of nodal involvement detection was 67.7% with PET and 75.8% with computed tomography (CT). Preoperative FDG-PET revealed colon cancer in 2 patients, adrenal tumor in 1 patient, lung cancer in 1 patient, and lung metastasis in 1 patient.ConclusionLarger or more advanced tumors with nodal involvement had a higher detection rate by PET. In EGCs, only the intestinal type was detectable by PET. PET-positive EGC may be aggressive, and an adequate lymphadenectomy must be done. Preoperative PET was useful for the detection of other malignancies and distant metastasis.

The usefulness of CEA and/or CA19-9 in monitoring for recurrence in gastric cancer patients: a prospective clinical study

AbstractBackground. Many studies on postoperative carcinoembryonic antigen (CEA) and/or carbohydrate antigen (CA)19-9 monitoring after operation for gastric cancer have been reported, but most have been retrospective. Methods. A nationwide observational study was implemented in 135 leading institutions in Japan to evaluate the significance of CEA and/or CA19-9 in postoperative monitoring for recurrence in patients with advanced gastric cancer. Three hundred and twenty-one patients examined in this analysis underwent radical gastrectomy at one of Japans leading institutions between November 1993 and March 1996 and had been followed up for at least 5 years. Serum levels of CEA and CA19-9 were examined preoperatively and every 3 months postoperatively, with diagnostic imagings, such as chest X-ray, computed tomography (CT), and ultrasonography also being performed every 3 months. Results. Recurrence was observed in 120 patients (peritoneum, 48; liver 16; lymph node, 16; multiple sites, 25; and others, 12). Sensitivities of CEA and either CEA or CA19-9, or both, for recurrence were 65.8% and 85.0%, respectively, both of which values were significantly higher than the preoperative positivities (28.3% and 45.0%, respectively). In most patients with high preoperative levels CEA and/or CA19-9, these tumor markers increased again at recurrence. Recurrent diseases were detected between 5 months after detection by diagnostic imagings and 12 months before detection by diagnostic imagings (mean of 3.1 ± 3.6 months before detection by diagnostic imagings) and between 10 months after detection by diagnostic imagings and 13 months before detection by diagnostic imagings (mean of 2.2 ± 3.9 months before detection by diagnostic imagings) by CEA and CA19-9 monitorings, respectively. Conclusion. These results suggest that CEA and/or CA19-9 monitoring after operation was useful to predict the recurrence of gastric cancer, especially in almost all the patients with high preoperative levels of these markers.

Prognostic factors in patients with advanced gastric cancer with macroscopic invasion to adjacent organs treated with radical surgery

Background. The prognosis of patients with gastric cancer with invasion to adjacent organs is poor. The prognostic factors of patients with advanced gastric cancer with macroscopic invasion to adjacent organs (T4) who were treated with radical surgery was determined in the present study. Methods. A total of 86 consecutive patients with advanced gastric cancer who underwent radical (potentially curable) gastrectomy with combined resection of other organs for macroscopic invasion to adjacent organs during surgery, were investigated. The organs invaded macroscopically were the pancreas in 43 patients, mesocolon in 29, liver in 7, transverse colon in 5, adrenal gland in 3, spleen in 1, diaphragm in 1, and other organs in 5. The prognostic factors were evaluated by univariate and multivariate analysis. Results. The cumulative 5-year survival rate of the patients treated by radical surgery with the combined resection of invaded organs was 35.0%. Multivariate analysis demonstrated that location of the tumor, lymph node metastasis, histological depth of invasion, and extent of lymph node dissection were significant prognostic factors in advanced gastric cancer patients treated by radical surgery with combined resection of adjacent organs for macroscopic invasion. Conclusion. For patients with macroscopic T4 gastric cancer located in the middle- or lower-third of the stomach, aggressive resection of invaded adjacent organs with extended lymph node dissection should be performed to improve long-term outcome.

Surgery for gastric cancer in patients with cirrhosis

To clarify the therapeutic strategies for gastric cancer surgery in the presence of cirrhosis, 39 patients with gastric cancer accompanied by liver cirrhosis were reviewed. Severe postoperative complications developed in 10 patients (25.6%), and there were 4 (10.3%) hospital deaths, 1 (2.6%) of which occurred within 1 month. Although extended lymph node dissection of D2 or more was adopted for low-risk patients, 3 of 19 patients who underwent such extensive operations, most of which involved complete lymph node dissection in the hepatoduodenal ligament, died. Conversely, only 1 of 20 patients who underwent limited lymph node dissection of D1 or less died. Postoperative massive ascites developed in 6 patients, 3 of whom died. The cumulative 5-year survival rate following curative resection was 63.7% for patients with early gastric cancer, and 13.9% for those with advanced gastric cancer. The most frequent cause of death was cirrhosisrelated, such as hepatic failure or hepatoma. In conclusion, extensive lymph node dissection for patients with gastric cancer accompanied by cirrhosis carried a risk of postoperative fatal massive ascites as lymphorrhea. Thus, lymph node dissection in the hepatoduodenal ligament should be avoided, except in patients with evident metastases, and as a rule, aggressive surgery should not be performed in cirrhotic patients.

Multiple early gastric carcinomas: Clinicopathologic features and histogenesis

Multiple early gastric carcinomas were found in 5–15% of patients with early gastric carcinoma. The goals of this study were to clarify the clinicopathologic features of multiple early gastric carcinomas and to investigate their histogenesis.

The protective effect of thromboxane A2 synthetase inhibitor against ischemic liver injury

To evaluate the role of thromboxane A2 (TXA2) in ischemic liver injury, the serum changes in thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (6-K-PGF1α) following warm ischemia of the total canine liver were examined, and the protective effect of a TXA2 synthetase inhibitor was assessed. Total liver ischemia was performed for 60 min on two groups of dogs: a control group, in which ischemia alone was performed, and an OKY-046 group, which received a TXA2 synthetase inhibitor. A temporary active portacaval shunt was used to eliminate the effects of splanchnic venous stasis during clamping of the hepatic pedicle. Postoperative changes in liver function, assessed by the transaminase enzyme levels, and in prostaglandins were recorded and the histologic liver findings of both groups 1 week after ischemia were compared. The levels of 6-K-PGF1α increased after reperfusion in both groups, while those of TXB2 increased in the control group but maintained low levels in the OKY-046 group. Liver function was better and histologic changes less marked in the OKY-046 group than in the control group, suggesting the important role of TXA2 in ischemic liver injury and the usefulness of a TXA2 synthetase inhibitor for protecting the liver against ischemic injury.

Principles of Surgical Treatment

Curative treatment of gastric cancer requires complete elimination of all cancer cells. Surgery is the only treatment method that can fully and demonstrably achieve this goal. However, in the clinical setting, the most appropriate procedure for each case must be selected, based on a full grasp and understanding of various local and systemic conditions.

Proximal subtotal gastrectomy for the treatment of carcinoma of the upper third of the stomach: Its indications based on lymph node metastasis and perigastric lymphatic flow

To clarify the indications for a proximal subtotal gastrectomy in the treatment of carcinoma in the upper third of the stomach based on lymph node metastases, 1055 patients in whom either a D2 or greater lymph node removal was performed were reviewed. In the patients in which the lesion was confined to the upper stomach and did not invade beyond the muscularis propria of the stomach wall, no metastases to either the lymph nodes above and below the pylorus or the lymph nodes along the greater curvature were observed. A lymphatic flow study revealed a minimal flow to these nodes from the upper stomach in patients without lymph node metastasis, but in cases with lymph node metastases the lymphatic flow changed. The indications for a proximal subtotal gastrectomy for a carcinoma of upper third of the stomach therefore must fulfill the following two conditions: (1) The deepest layer of cancerous invasion does not extend beyond the muscularis propria of the stomach wall, and (2) No macroscopic evidence of lymph node metastasis can be detected during surgery.

Surgery for cholelithiasis in cirrhotic patients

Although biliary tract surgery for cholelithiasis is performed frequently in Japan, cirrhotic patients require special consideration. Postoperative complications after biliary tract surgery were studied in 23 patients with liver cirrhosis and associated cholelithiasis, 9 of whom had no complications, 8 had minor complications, and 6 had severe complications. Concerning the relation between Childs classification and postoperative complications, no complications were seen in four Childs type A patients, but seven of ten (70%) Childs type B patients and seven of nine (78%) Childs type C patients developed complications. Two (20%) of the Childs type B patients and four (44%) of the Childs type C were severe, and three of the latter group died. Regarding the preoperative laboratory findings, significant differences were seen between the patients without complications and those with severe complications in serum bilirubin, albumin, and ICG R15 values. Of the six patients with severe complications, five had choledocholithiasis, three of whom died of liver failure, while two developed biliary peritonitis caused by insufficient fistula formation after removal of the T-tube. Thus, for the treatment of choledocholithiasis in patients with severe cirrhosis, avoiding surgical invasion through the use of such techniques as endoscopic papillotomy is recommended whenever possible.

Proliferating cell nuclear antigen expression in the gallbladder with pancreaticobiliary maljunction

Background and Objective: To clarify the histogenesis of cancer of the gallbladder of the patients with pancreaticobiliary maljunction (PBMJ), the proliferating cell activity of the epithelium of gallbladder was examined.