Effect of age on the relationship between gastric cancer and Helicobacter pylori. Tokyo Research Group of Prevention for Gastric Cancer

Helicobacter pylori is thought to be involved in the pathogenesis of gastric cancer, but the time point at which it produces its effects (critical time) is unknown. We measured the serum level of H. pylori antibody in 787 gastric cancer patients and 1007 controls aged 20 to 69. Odds ratios for different gastric cancer types and stages were determined for each 10-year age class. The overall odds ratio for gastric cancer decreased with age, being 7.0 for those aged 20 - 29, 14.5 for those aged 30 - 39, 9.1 for those aged 40 - 49, 3.5 for those aged 50 - 59, and 1.5 for those aged 60 - 69 (trend in odds ratios: P < 0.01). However, there was no such age-dependent trend for early diffuse-type cancer; the odds ratios were 12.6, 4.0, 7.2, 6.5, and 18.5 respectively (P = 0.29). Early cancer tended to show higher seroprevalence than advanced cancer, especially in older subjects. No significant difference in seroprevalence was observed between diffuse and intestinal cancers within each age-class. Seroreversion must have occurred in the time interval between the critical time and the diagnosis of the cancer, especially in older patients. The age-dependent relationship between H. pylori and gastric cancer may be due to seroreversion, which itself may be independent of age. This age-independence indicates that prolonged exposure to H. pylori does not increase the magnitude of its influence on gastric carcinogenesis. Possible mechanisms through which H. pylori exerts pathogenic effects are continuous inflammation in adulthood and / or irreversible damage to gastric mucosa in childhood or the teenage years.

Positron emission tomography of esophageal carcinoma using (11)C-choline and (18)F-fluorodeoxyglucose: a novel method of preoperative lymph node staging

BACKGROUND

Accurate preoperative staging is an important but difficult problem in determining therapy for patients with esophageal carcinoma. Positron emission tomography (PET) is used with [methyl-(11)C]choline ((11)C-choline) and 2-[(18)F]fluoro-2-deoxy-D-glucose ((18)F-FDG) to detect a variety of malignancies. The authors used PET with both of these agents to detect lymph node metastases in patients with esophageal carcinoma.

METHODS

Lymph node metastases in 33 patients with biopsy-proven esophageal carcinoma (16 patients with tumors classified as T1 and 17 patients with tumors classified as T2-4) was examined by PET using (11)C-choline and (18)F-FDG, and the accuracy of the results was correlated with pathology findings after surgery.

RESULTS

(11)C-choline PET was more effective than (18)F-FDG PET and computed tomography (CT) in detecting very small metastases localized in the mediastinum. It was ineffective, however, in detecting metastases localized in the upper abdomen, because of the normal uptake of (11)C-choline in the liver. (18)F-FDG PET was superior to CT in detecting metastases in the mediastinum and the upper abdomen, whereas (11)C-choline PET was superior to (18)F-FDG PET in detecting metastases in the mediastinum. When (11)C-choline PET and (18)F-FDG PET were used in combination, they were very effective in evaluating the lymph node status in both the mediastinum and the upper abdomen, and detected 85% of the metastatic lymph nodes (n = 46).

CONCLUSIONS

In this study, the combination of (11)C-choline PET and (18)F-FDG PET was very effective in evaluating the lymph node status of patients with esophageal carcinoma preoperatively.

[International perspectives on the treatment of gastric cancer]

Our experience of treatment of gastric cancer in European and developing countries suggested the necessity of the establishment of both operative and chemotherapeutic modalities. These modalities should be first based on theoretically convincing data and secondarily well analyzed from the viewpoint of cost-effectiveness.

An experience of treatment for patients with thoracic esophageal cancer invading adjacent organs

The treatment of patients with thoracic esophageal cancer invading adjacent organs is controversial. The effect, on survival, of esophagectomy with regional node dissection after combined chemotherapy and radiotherapy was studied in six patients with the esophageal cancer. Two patients undergoing esophagectomy survived > 39 months without relapse. Postoperative complications were not observed in patients undergoing esophagectomy with a two-step surgical procedure (interval of several weeks between esophagectomy and reconstruction), while complications were observed in all patients undergoing a one-stage surgical procedure. Two-step esophagectomy with regional node dissection after combined chemo- and radiotherapy is a promising option for patients with esophageal cancer invading adjacent organs.

[Esophagobronchial fistula and empyema resulting from esophageal carcinoma]

A 59-year-old woman was admitted to the hospital with a one-month history of hemoptysis, generalized fatigue, and a high fever. A chest X-ray film obtained on admission showed a massive right-sided pleural effusion. Examination of an aspirate showed a high level of amylase, and bacteria that were the same as oral bacteria. Closed drainage yielded ichorous pus and food residues, which led us to the diagnosis of empyema caused by esophageal perforation. Esophagography and fiberoptic esophagoscopy revealed that an esophagobronchial fistula related to an advanced esophageal carcinoma had caused the empyema. Surgical resection was done, and the patient was alive at the time of this writing, 7 months after she was first treated. Esophageal carcinoma is sometimes accompanied by esophagobronchial fistula. Patients with this condition usually have severe respiratory symptoms; those presenting with empyema are rare. Esophageal carcinoma must be carefully ruled out as the cause of empyema.

Results of 90 consecutive hepatectomies for hepatocellular carcinoma: a multivariate analysis of survival

The surgical results and postoperative management of 90 patients with hepatocellular carcinoma (HCC) who underwent hepatectomy were reviewed, and clinical factors relating to HCC were analyzed to determine what type of HCC responds best to hepatectomy. The patients consisted of 69 men and 21 women. Serum anti-hepatitis C virus was positive in 76.9% of patients and hepatitis B surface antigen was positive in 18.9%. The operative procedures consisted of right lobectomy in six patients, left lobectomy in seven, right hepatic segmentectomy in eight, left lateral segmentectomy in 13, two adjoining subsegmentectomy in 17, subsegmentectomy in 29, and partial hepatectomy in 10. Liver cirrhosis was confirmed histopathologically in 63 patients. There were two operative deaths and two other in-hospital deaths. During the follow-up period, HCC recurred in 64 of the remaining 86 patients at the following sites: liver in 56 patients (87.5%), bones in four (6.3%), lymph nodes in three (4.7%), and lung in one (1.6%). Transcatheter arterial chemoembolization was performed in 22 of the patients with recurrence, transcatheter arterial chemoembolization in combination with percutaneous ethanol injection was performed in 14, hepatectomy was performed in six, and irradiation with Linac x-rays was performed in eight. The cumulative 3- and 5-year survival rates were 63.8% and 37.8%, respectively. Univariate and multivariate analyses of factors influencing survival disclosed that having a single HCC nodule of up to a maximal diameter of 4.0 cm, an absence of intrahepatic metastasis, and a functional liver reserve estimated as clinical stage I contributed significantly and independently to increasing the survival rate.

Pancreatic exocrine function during acute exacerbation in WBN/Kob rats with spontaneous chronic pancreatitis

CONCLUSION

Pancreatic exocrine hypofunction is markedly deteriorated during acute exacerbation in a rat model with chronic pancreatitis.

BACKGROUND

Little is known about pancreatic exocrine function during acute exacerbation in patients with chronic pancreatitis. We investigated changes in pancreatic exocrine function after inducing acute pancreatitis in an animal model of spontaneous chronic pancreatitis.

METHODS

WBN/Kob rats with chronic pancreatitis sequentially underwent pancreatic exocrine function test 1-6 d after surgical preparation with external pancreatic fistula. We induced acute pancreatitis in another WBN/Kob rats by i.v. administration of cerulein at a rate of 10 micrograms/kg/h for 4 h 4 d after surgical preparation. Pancreatic exocrine function test was undertaken in a conscious state 1 d before and after cerulein administration.

RESULTS

In WBN/Kob rats not given cerulein, pancreatic exocrine function remained almost constant at 3-6 d after surgery. Marked hyperamylasemia developed immediately after cerulein administration. After its administration, the pancreas microscopically showed prominent interstitial edema and intracellular vacuolization of acinar cells in addition to the finding of pre-existing chronic pancreatitis. Basal and cholecystokinin-stimulated flow rate, bicarbonate output, and protein output, which were substantially impaired 1 d before cerulein administration, were further reduced 1 d after its administration.

Primary carcinoma of the gallbladder: role of external beam radiation therapy in patients with locally advanced tumor

BACKGROUND/AIM

Several reports have demonstrated that occasional long-term survival might be obtained with external beam radiation therapy in patients with gallbladder cancer. However, there are few reports which evaluate the local effect of irradiation. The aim of our study was to investigate the local effect of radiation therapy. and to evaluate its role for locally advanced gallbladder cancer.

PATIENTS AND METHODS

Twenty-two patients with locally advanced gallbladder cancer were treated with high-dose external beam radiation therapy. Tumor resection was performed in 5 patients, palliative surgery in 5, and the remaining 12 patients were treated by radiation therapy alone.

RESULTS

Overall survival was 36% at 1 year, 18% at 3 years and 14% at 5 years. All but 2 patients developed local recurrence and died of disease at 1 to 99 months after radiation therapy. Among 17 patients who had not undergone tumor resection, partial response was obtained in 4 patients and no response in 13. Survival times in patients who achieved partial response were 14, 26, 47 and 99 months, whereas those of no response were 1 to 12 months with a mean of 4.8 months. Survival between these 2 groups (partial vs. no response) showed significant difference (p = 0.0008, logrank test).

CONCLUSION

It is concluded that high-dose external beam radiation therapy could improve survival in some patients with unresectable gallbladder cancer.

Effect of oral administration of protease inhibitor on pancreatic exocrine function in WBN/Kob rats with chronic pancreatitis

The effect of oral administration of protease inhibitor (camostat) on pancreatic morphology and exocrine function (conscious rat model) was investigated using WBN/Kob rats with spontaneous chronic pancreatitis. In nontreated WBN/Kob rats (2-12 months of age), pancreatic fibrosis and parenchymal destruction compatible with human chronic pancreatitis appeared at 3 months and advanced with each month. Pancreatic secretion was markedly impaired at all ages. In WBN/Kob rats fed diets containing camostat (from 2-3 or 4-5 months of age), the pancreas was hypertrophic and did not show any histological appearances compatible with chronic pancreatitis, and moreover, exocrine function was thoroughly restored with increased plasma cholecystokinin concentrations. Oral administration of protease inhibitor has both preventive and therapeutic effects on pancreatic lesions and dysfunction in an animal model of chronic pancreatitis, probably via endogenous cholecystokinin release.

Appendical fistulae formation as a complication of primary Crohn's disease prior to surgical management: report of a case

We report herein the unusual case of a 55-year-old man who presented with primary Crohn's disease of the appendix with fistulae. In this patient there was no history of previous appendectomy. Although fistula formation around the orifice of the appendix after appendectomy for primary Crohn's disease of the appendix has been observed in a number of long-term follow-up studies, preoperative fistula formation is extremely rare.

[A case of advanced gastric cancer successfully treated with combination chemotherapy using THP, 5'-DFUR and CDDP, followed by surgical resection]

We reported a patient with advanced gastric cancer and a liver metastasis, who responded remarkably to combination chemotherapy using THP, 5'-DFUR and CDDP. The patient was administered four courses of THP (15 mg/m2/day, on day 1, iv), 5'-DFUR (1400 mg/m2/day, on days 1-4 and 15-18, orally), and CDDP (80 mg/m2/day, on day 5, iv) every 4 weeks. As a result, both the primary and metastatic tumors decreased remarkably in size at more than 19 weeks (PR) and we performed curative total resection of the stomach and partial resection of the liver. Histologically, the effects of chemotherapy on gastric focus were evaluated as grade 1a and the liver metastasis completely disappeared. This combination therapy proved useful to treat advanced gastric cancer in this patient.

Prediction of pulmonary complications after transthoracic oesophagectomy

Postoperative pulmonary complications are often fatal in patients with oesophageal cancer. The influence of various preoperative and perioperative risk factors in the prediction of such complications was analysed. Some 170 oesophageal resections performed through a thoracotomy between January 1977 and December 1991 were reviewed. Twenty-two parameters generated from various medical risk categories were studied. Six variables were significant (P < 0.05) on univariate analysis: vital capacity, serum albumin level, partial pressure of carbon dioxide in arterial blood, presence of liver cirrhosis, presence of chronic obstructive airway disease and clinical stage of the tumour. Multivariate discriminant analysis of these six factors identified three as significant, namely vital capacity (P < 0.0001), liver cirrhosis (P = 0.01) and tumour stage (P = 0.01), yielding an equation for assessment of the risk of postoperative pulmonary complications. Calculation of the risk score showed that 42 of 53 patients with pulmonary complications had scores of 0 or more and that 74 of 102 without had scores below 0. The mean risk score was 0.34 for patients with complications and -0.26 for those without. The equation predicted pulmonary complications after transthoracic oesophagectomy with 74.8 per cent accuracy, 79.2 per cent sensitivity and 72.5 per cent specificity. It is concluded that the risk of postoperative pulmonary complications can be accurately assessed in individual patients by calculation of a risk score based on vital capacity, liver cirrhosis and tumour stage.

Immunotherapy for Stewart-Treves syndrome. Usefulness of intrapleural administration of tumor-infiltrating lymphocytes against massive pleural effusion caused by metastatic angiosarcoma

We describe a 56-year-old woman with Stewart-Treves syndrome who had severe dyspnea from a pleural effusion caused by metastatic angiosarcoma in the right lung. Tumor-infiltrating lymphocytes (TIL) in the pleural effusion were cultured and expanded in vitro in the continuous presence of recombinant interleukin 2 with periodic stimulation by CD3 antibody. The expanded TIL were administered intrapleurally seven times at 1- to 4-week intervals in combination with intravenous infusion of recombinant interleukin 2. A panel of T-cell clones was also obtained from TIL. Immunotherapy dramatically improved the patient's dyspnea and pleural effusion. A CD4+ T-cell clone and a CD8+ T-cell clone established from TIL had specific cytotoxicity to the tumor cells.

The macroscopic diagnosis of lymph node metastasis from early gastric cancer

As the proportion of early gastric cancers (EGC) has been steadily increasing, modifications of the "radical lymphadenectomy" approach to stomach cancer have been attracting considerable attention; however, accurate pre- and intraoperative evaluations of tumor extent are essential for the successful application of this method. We examined the reliability of macroscopically diagnosing node involvement by reviewing the operative and pathological records of 522 patients with EGC. Of 59 patients histologically diagnosed as node-positive (n+), only 19 (32%) had been macroscopically diagnosed as node-positive (N+). In contrast, of 61 N+ patients, 42 (69%) were in fact n-. Metastases from histologically diffuse type carcinomas were less accurately diagnosed than those from intestinal type tumors. In 44% of the false-positive (N+/n-) patients, the tumor had been preoperatively diagnosed as advanced, which seemed to have lead to intraoperative overdiagnosis. These results suggest that lymph node metastases from EGC cannot be reliably diagnosed during surgery. The indications for a modified radical operation should thus be decided according to preoperative tumor evaluation based on the depth of invasion.

Effect of experimental hypochlorhydria on the histological differentiation of adenocarcinomas in the canine stomach

Hypochlorhydria is considered to be a risk factor for gastric cancer, both clinically and experimentally. In humans, the hypo-acidic condition appears to be closely associated with the development of differentiated-type gastric carcinomas. We investigated relationships between antral pH and histological types of gastric cancer using an animal model. A total of 7.65 g of N-ethyl-N'-nitro-N-nitrosoguanidine (ENNG) was orally administered to male beagle dogs. Subsequently, the dogs were divided into four groups and underwent four surgical interventions designed to create various conditions in the antrum. Antral pH was recorded at the time of killing after an observation period ranging from 16 to 33 months. The number of gastrin-secreting cells (G-cells) was counted after immunohistochemical staining. Carcinomas were found in the antrum of 12 of the 21 dogs that had survived. Although limited doses of ENNG, such as those used in this study, have been reported to produce only undifferentiated adenocarcinomas, differentiated adenocarcinomas were found in seven of these 12 dogs. Antral pH and the number of G-cells were significantly higher in these seven dogs than in the other five dogs, which had developed only undifferentiated adenocarcinomas. Bile inflow showed no significant effect on the development of differentiated adenocarcinomas. Neither atrophic gastritis nor intestinal metaplasia was seen in any of the dogs. These results suggest that the hypo-acidic condition itself may play a role in the development of differentiated adenocarcinomas.

Role of reflux oesophagitis and acid in the development of columnar epithelium in the rat oesophagus

The role of reflux oesophagitis and acid in the development of oesophageal columnar epithelium was investigated in the rat. Twenty-four animals underwent total gastrectomy and oesophagojejunostomy, inducing reflux of duodenal contents into the oesophagus, and were divided into two groups: an 'acid' group, which drank syrup water with hydrochloric acid (pH 1.8), and a 'non-acid' group, which drank only syrup water (pH 6.5). Four rats were killed at 4, 8 and 12 weeks after surgery. Reflux oesophagitis was found in the lower portion of the oesophagus in all cases. Columnar epithelium was observed in the oesophagus of one rat in the non-acid group at week 8 and of three in the acid group at week 12. These results indicate that the development of columnar epithelium of the oesophagus is preceded by reflux oesophagitis and that acidic conditions may promote this change. Columnar epithelialization may result from metaplasia of squamous epithelium as well as from upward extension of columnar epithelium.

Lymph node metastasis from early gastric cancer: endoscopic resection of tumour

The clinicopathological features of 748 solitary early gastric cancers were examined with regard to lymph node metastasis. Among several factors, only depth of invasion and tumour size correlated significantly with node involvement. Tumours which satisfy the following criteria may not metastasize to lymph nodes: (1) confined to the mucosa; (2) less than 1.5 cm in diameter; (3) macroscopically elevated; (4) macroscopically depressed, without intramural ulcers or ulcer scars (endoscopically, no fold convergence); and (5) histologically differentiated. With a recently developed endoscopic technique small gastric tumours can safely be resected. The cut margin and depth of tumour invasion can be verified histologically in the specimen. If an endoscopically removed tumour satisfies the above criteria, further surgical intervention may be optional as the outcome of endoscopic resection is comparable to that of radical surgery in the absence of node involvement.

Marked and prolonged depression of factor XIII after esophageal resection

Anastomotic leakage is one of the most common complications of esophagectomy and, since Factor XIII is required for normal wound healing, we investigated the temporal changes in plasma Factor XIII following esophagectomy and hepatectomy. A control group of patients undergoing other abdominal operations was also studied. Factor XIII activity was determined before surgery and on postoperative days (POD) 1, 3, 7 and 14. The plasma levels of acute phase protein were also measured. The plasma Factor XIII activity decreased significantly in both the hepatectomy and control groups until POD 7, reaching the lowest level on POD 3. In contrast, the esophagectomy group showed significant decreases in Factor XIII levels throughout the postoperative study period, with a nadir with an average activity of 56 per cent on POD 7. Preoperative transferrin levels had a positive correlation with Factor XIII levels measured on POD 3 and there was also a positive significant correlation between Factor XIII activity and alpha 2-macroglobulin levels on POD 3. These results suggest that there is a marked and prolonged depression of plasma Factor XIII activity following esophagectomy which may be attributed to accelerated tissue demands, inadequate synthesis or increased degradation. Moreover, the severe and sustained decrease in Factor XIII activity may be related to poor wound healing after esophagectomy.

The role of alkaline reflux in esophageal carcinogenesis induced by N-amyl-N-methylnitrosamine in rats

It is now accepted that the incidence of esophageal carcinoma is highest in the middle thoracic region. Esophageal carcinoma after gastrectomy, however, has a tendency to develop in the lower thoracic region. These studies suggest a possible correlation between the development of esophageal carcinoma and gastrectomy, i.e., alkaline reflux into the esophagus. To elucidate this correlation, the role of alkaline reflux of duodenal contents in the development of esophageal squamous-cell carcinoma induced by N-amyl-N-methylnitrosamine (AMN) was investigated in Wistar rats. The animals were divided into 3 groups; gastrectomized rats with or without regurgitation of duodenal contents into the esophagus, and control rats without gastrectomy. All received low doses of AMN for 8 weeks and were subsequently killed for pathological examination. Esophageal squamous-cell carcinomas were found only in gastrectomized rats with regurgitation. The carcinomas were found exclusively in areas of reflux esophagitis and were accompanied by severe dysplasia. Our results indicate that alkaline reflux of duodenal contents strongly contributes to the development of esophageal squamous-cell carcinoma.

Active components of intestinal bacteria for abdominal irradiation-induced inhibition of lung metastases

We have previously reported that abdominal irradiation of mice inhibited lung metastases of a weakly immunogenic fibrosarcoma, and that transmigration after the irradiation of Enterobacter cloacae into mesenteric lymph nodes coincided with this phenomenon. In this paper, we show that Escherichia coli as well as E. cloacae reduce the number of metastatic lung colonies when these bacteria were intravenously injected into mice prior to the tumour cell challenge. The inhibition was caused not only by the administration of living bacteria but also by that of killed bacteria. Bacterial lipopolysaccharide (LPS), a component of membrane, replaced at least in part the effect of whole bacteria. Transfer of spleen cells from LPS-treated mice into intact recipients prominently inhibited metastatic development in the recipient mice. 'Cross transfer' between LPS high responders and LPS low responders suggested an indirect activity of transferred spleen cells. The antimetastatic activity of LPS depended on the tumour cell type; metastasis of fibrosarcomas was extensively inhibited by LPS irrespective of tumour immunogenicity while that of adenocarcinomas was only slightly inhibited. These results suggest that non-immunological mechanisms are involved in the antimetastatic activity of LPS.

Early gastric cancer. Endoscopic diagnosis of depth of invasion

In order to decide on a treatment strategy against gastric cancers, an accurate preoperative evaluation of the depth of cancer invasion is essential. Preoperative endoscopic diagnosis of the depth of invasion was compared with pathological results of the resected specimen in 206 early gastric cancers and 32 early-like advanced gastric cancers. The endoscopic distinction between early and early-like advanced cancers was correctly made in 83.6% of the cases. Among the early gastric cancers, mucosal and submucosal invasion was correctly presumed in 71.9% of the cases. When the tumor was an elevated type, or located in the antrum, the endoscopic diagnosis tended to be deeper than the true depth. The size of tumor contributed little to the depth diagnosis. Pathomorphological changes on the tips of converging folds were the important clue for diagnosing depth.

[Successful resection of mediastinal and abdominal recurrent tumors of esophageal leiomyosarcoma 12 years after surgery]

A 57-year-old woman admitted to our hospital in October, 1988 because of the tumor of the abdominal wall and abnormal shadows of right chest wall and right upper mediastinum. Her esophagus had been resected and reconstructed by the stomach roll because of the esophageal leiomyosarcoma in May, 1976. Clinical examinations revealed that the abdominal mass and chest shadows were the recurrence of the leiomyosarcoma. The abdominal tumor was resected on 17th October, 1988. On 14th December, 1988 right thoracotomy was performed. Chest wall tumor (40 x 30 x 20 mm) and mediastinal tumor (45 x 40 x 35 mm) were resected completely. The mediastinal tumor was adhered to the remnant esophageal muscle layer. Microscopic section of the tumor showed spindle cell sarcoma with fine calcification, and it was diagnosed as the metastatic leiomyosarcoma.

[An advanced gastric carcinoma which responded to combined administration of mitomycin C, FT-207, and lentinan immunochemotherapy]

A 59-year-old man with a gastric cancer underwent a laparotomy and was found to have an unresectable tumor that formed a large mass with metastatic lymph nodes around the aorta. He therefore was treated by a combined administration of Mitomycin C, FT-207, and Lentinan for 3 months. Remarkable tumor reduction was observed endoscopically, and a subtotal gastrectomy was performed. The immunochemotherapy then was resumed, and the patient has survived for 16 months despite the remnant lymph node metastases. A histological examination of the resected stomach revealed a marked degeneration of the tumor.

[A carcinoma of the right breast arising after a mastectomy in primary malignant lymphoma of the left breast]

In 1987, a 51-year-old woman visited our hospital, having noticed a painless 1.5 x 1.5 cm tumor of the left breast. On biopsy, it was pathologically diagnosed as being a primary malignant lymphoma of the breast. Thus we performed a modified radical mastectomy (Patey's method), in combination with chemotherapy (Cyclophosphamide, Vincristine, Prednisolone). Two years after the operation, a tumor of the right breast, 1.0 x 1.0 cm in size, was noticed. At this time, since an excised specimen was pathologically determined as being a scirrhous carcinoma, we performed a modified radical mastectomy (Auchincloss' method), followed by chemotherapy (Tegafur).

DNA methylation in rat stomach and duodenum following chronic exposure to N-methyl-N'-nitro-N-nitrosoguanidine and the effect of dietary taurocholate

N-Methyl-N'-nitro-N-nitrosoguanidine (MNNG) induces a high incidence of carcinomas in the glandular stomach of rats following chronic administration in the drinking water. We determined the level of 7-methylguanine and O6-methylguanine in gastric and duodenal DNA during chronic exposure to MNNG (80 p.p.m.). After considerable fluctuations during the initial 3 weeks, levels of methylpurines reached a steady state which was approximately three times higher in the pylorus (i.e. the preferential site of tumor induction) than in the fundus and duodenum, with 7-methylguanine and O6-methylguanine values in the range of 520 and 110 mumol/mol guanine, respectively. When rats were given MNNG in the drinking water at concentrations ranging from 10 to 80 p.p.m. for 3 weeks, levels of methylpurines reached maximum values already at 10-20 p.p.m. At higher MNNG concentrations, there was no further increase in DNA alkylation. The reason for this lack of dose response remained unclear. Immunohistochemical analyses showed that DNA methylation by MNNG is restricted to epithelial cells bordering the luminal surface. The possibility exists that in this target cell population the content of free thiols is a limiting factor for the decomposition of MNNG and its reaction with macromolecules in the gastric mucosa. Addition to the diet of sodium taurocholate, a bile acid previously shown to enhance MNNG-induced stomach carcinogenesis, did not influence the extent of DNA methylation, indicating that it acts as a promoter.

[A case of superficial carcinoma of the esophagus on esophageal varices]

We report a case of superficial esophageal carcinoma in a patient with esophageal varices. Esophagogram revealed a 2 cm large irregular mucosal elevation during work-up for esophageal varices which was acertained on endoscopical examination to be carcinoma. Biopsy material showed moderately differentiated squamous cell carcinoma. Subtotal esophagectomy was performed followed by reconstruction by cervical esophagogastrostomy through the retrosternal route. Few resected cases of esophageal carcinomas accompanied by esophageal varices have been reported because 1) early radiographic abnormalities of small superficial esophageal carcinomas can be overlooked in the case of large varices and 2) the number of operable cases is limited because of associated liver cirrhosis.

[Comparative studies on the DNA content of human gastric cancer cells and its metastatic foci]

Comparative cellular DNA content measurements have been done on two sites differing from each other in their anatomical location, in 16 cases of gastric cancer by means of microphotometry. In addition, comparisons on the DNA stemline of the original gastric lesions and their metastatic lesions (8 cases of liver metastases and 9 cases of lymph node metastases) also were done. The main stemlines in four cases (25%) out of 16 gastric cancers exhibited different main DNA stemlines from the other sites in the same lesion, although in the other 12 cases examined, two sites showed the same DNA stemlines to each other. In almost all cases, the DNA stemlines of the metastatic foci were consistent with those of the original lesions. The lymph node metastases simulated the original lesions in its DNA stemlines (89%) more than did the cases of livermetastases (63%). In an exceptional case, the original lesion exhibited two definite stemlines (2C & 3.5C), but only one (2C) was recognizable in the metastatic focus of the liver. This difference indicates the probable role of "clonal selection" in a blood-borne metastasis.

Expression and function of class II antigens on gastric carcinoma cells and gastric epithelia: differential expression of DR, DQ, and DP antigens

The expression of human histocompatibility leukocyte antigen class II antigens on gastric epithelia and gastric carcinoma (GaCa) was studied with the use of murine monoclonal antibodies to DR, DQ, and DP antigens. DR and DP antigens but not DQ antigens were demonstrated in fundic glands of normal gastric epithelia, and DP+ cells were located in part of the DR+ epithelia. Of 15 GaCas examined, 11 expressed DR antigen, and the degree of the expression varied considerably among the specimens. DP antigen was found in 3 of the 11 DR+ carcinomas, and the DQ antigen was found in one of the 3 DR+ DP+ specimens. Thus the expression of class II antigens in normal gastric epithelia and GaCas appears to be in the order of DR, DP, and DQ. Studies on 3 GaCa cell lines (Kato III, MKN28, and MKN45) demonstrated that 1 line (Kato III) expressed DR antigen only, and the remaining lines were negative. Interferon (IFN)-gamma treatment enhanced the expression of DR antigen on Kato III cells and induced expression of DQ and DP antigens. The IFN-gamma treatment also induced expression of DR antigen but not DQ or DP antigens in 1 of the 2 negative cell lines. The induction of the class II antigens by IFN-gamma was shown to be dose dependent. However, maximal induction of DQ and DP antigens on the Kato III cells and DR antigens on MKN45 cells required 10 times more IFN-gamma than that needed for the maximal expression of DR antigen on Kato III. Northern blot analyses of cytoplasmic RNA from these cells were in agreement with and affirmed the above-described expression of the class II antigens on the cell lines. The DR antigen on the Kato III cells was capable of stimulating allogeneic lymphocytes in MLR, and its stimulatory activity was significantly enhanced by IFN-gamma. These results demonstrated a differential expression of class II antigens in the "DR, DP, and DQ order" in normal gastric epithelia, GaCa cells, and GaCa cell lines, suggesting different mechanisms acting discordantly on the expression of each of these antigens and that the DR antigen on the GaCa cell lines possesses MLR-stimulatory ability.

Expression of epidermal growth factor receptors on normal human gastric epithelia and gastric carcinomas

Tissues of normal human gastric mucosae and 15 advanced gastric carcinomas were studied immunohistologically for the presence of receptors for epidermal growth factor (EGF) by use of a murine monoclonal antibody (528IgG), which reacts with the binding domain of human EGF receptor. On normal gastric mucosae, only parietal cells showed positive staining. On cancer tissues, definite staining was observed in 9 of 15 cases. Their staining intensities were variable and weaker in general compared to those of either gastric parietal cells or normal tonsilar squamous epithelium. No apparent correlation of EGF receptor staining with the grade of histologic differentiation or lymph node metastases of these gastric carcinomas was noted.

Enhancing effect of bile and bile acid on stomach tumorigenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine in Wistar rats

The carcinogenic or cocarcinogenic effects of bile or bile acid on stomach carcinogenesis were investigated in inbred W rats. Bile or bile acid was introduced into the stomach by choledochogastrostomy or with food after the administration of N-methyl-N'-nitro-N-nitrosoguanidine [(MNNG) CAS: 70-25-7; 1-methyl-3-nitro-1-nitrosoguanidine] in drinking water. The animals that received MNNG and bile or sodium taurocholate (CAS: 145-42-6; N-choloyltaurine sodium salt) had a significantly higher incidence of hyperplastic and neoplastic lesions in the stomach mucosa than did the relevant MNNG-treated controls. The result suggested an enhancing effect of bile and sodium taurocholate in stomach tumorigenesis.

Enhancing effect of sodium taurocholate on N-methyl-N'-nitro-N-nitrosoguanidine-induced stomach tumorigenesis in rats

Male Wistar rats that had received a low dose of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and sodium taurocholate showed a significantly higher incidence of hyperplastic and neoplastic lesions in the stomach mucosa than did the MNNG-treated controls. The result suggested an enhancing effect of taurocholate in stomach tumorigenesis.

Vitamin D status after total gastrectomy

Serum levels of 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, 1,25-dihydroxyvitamin D, immunoreactive parathyroid hormone, and urinary excretion of nephrogenous cyclic AMP were measured in 25 patients after total gastrectomy. Two types of reconstruction after total gastrectomy were also compared. Serum 25-hydroxyvitamin D levels were significantly decreased and serum 24,25-dihydroxyvitamin D levels were markedly reduced, whereas serum 1,25-dihydroxyvitamin D levels were significantly increased in the patients. Although serum levels of immunoreactive parathyroid hormone did not show a significant difference, serum alkaline phosphatase levels and urinary excretion of nephrogenous cyclic AMP were significantly increased in the patients. The results suggest that defective vitamin D storage and enhanced vitamin D action coexist in patients after total gastrectomy and that the enhanced vitamin D action, possibly derived from slightly increased parathyroid function, would be a compensatory mechanism to sustained calcium deficiency. No substantial difference of vitamin D status was observed between the two types of reconstruction which differed in passage through the duodenum.

Superficial carcinoma of the esophagus

Nine cases of superficial carcinoma of the esophagus were described. Although 3 patients complained of abdominal sensations on swallowing or dysphasia, 6 patients did not present with any symptoms related to the esophageal lesion. The radiologic diagnosis is particularly difficult in cases with superficial type esophageal cancer, and no definitive findings were obtained in three such cases. However, esophagoscopy using Lugol spray was far more effective for the recognition of these superficial lesions. Although surgical resection of the esophagus is technically easier in these cases, the indications of surgery should be carefully evaluated. One operative death occurred in our series. In cases that are good indications, however, wide lymph node dissection should be carried out, since metastases occur even to distant lymph nodes, particularly in cases with cancer invasion of the submucosal layer. The histopathologic diagnosis was squamous cell carcinoma in 8 cases, but in one case it was adenocarcinoma of mucus-secreting gland origin in the mid-thoracic esophagus.

[Leiomyoma and leiomyosarcoma of the esophagus: report of 9 cases and review of the Japanese literature]

Seven cases of leiomyoma and two cases of leiomyosarcoma of the esophagus were presented. Review of the Japanese literature revealed a total of 260 cases of the former and only 35 cases of the latter, including our own cases. They occurred more frequently in males than females, by a ratio of 1.6:1 and 1.8:1, respectively. The patients with leiomyosarcoma distributed in higher age groups. The most frequent symptom was dysphagia in both groups of the cases, but in cases of leiomyosarcoma the incidence was much higher and the duration of the symptom was shorter. About 20% of the patients with leiomyoma were asymptomatic. Although the size of leiomyosarcoma tended to be larger, giant leiomyomas more than 10 cm in diameter were found in 18% of the cases. The lower third of the esophagus was the site of both tumors in over half of the cases, the middle third being the next frequent. The surgical removal by enucleation was the procedure of choice for leiomyoma. However, when either the tumor is densely adherent to the mucosa for considerable length or accidental extensive mucosal tear occurs, esophageal resection is recommended. Postoperative morbidity was minimal and results were generally excellent. On the contrary, esophageal resection including the tumor was indicated for leiomyosarcoma. The long-term results were poor particularly in cases of infiltrating-type lesions, though survival data could not be fully evaluated.