Intestinal-type tumour in resected gastric remnant cancer

Lauren's intestinal type of gastric cancer was proposed to be dependent on long-term environmental factors and is always preceded by chronic premalignant change. A cohort study was performed and demonstrated an increased cancer risk of gastric remnant after gastric surgery for benign disease. It is generally believed that after gastrectomy the residual stomach has an environmental change and, thus, enters a neoplastic process. Based on the carcinogenic theory of intestinal-type tumour, it would be of interest to know whether the intestinal-type tumour is more common in gastric remnant cancer. Forty patients with gastric remnant cancer had gastrectomy in the Veterans General Hospital-Taipei. Another 683 patients with primary gastric carcinoma underwent resection and were used as controls. The clinical characteristics, tumour stage and intestinal-type tumour were analysed in gastric remnant cancer and were compared with the various portions of primary gastric carcinoma. Although the overall distribution of intestinal-type carcinoma in gastric remnant (45%) was no different to that of any other portion of stomach cancer, intestinal-type carcinoma was more common in the early stage of gastric remnant (73%) and distal stomach (73%), but not in the proximal stomach (50%), which was supposed to have the same characteristics as the gastric remnant because of identical anatomic location. More than expected, intestinal-type carcinoma in early gastric remnant cancer together with a long incubation interval between primary surgery and later tumour occurrence were compatible with the theory of carcinogenesis of intestinal-type carcinoma.

Randomized trial of three types of gastrojejunostomy in unresectable periampullary cancer

BACKGROUND

A gastrojejunostomy with duodenal partition was designed to clarify whether so-called circulus vomiting exists and, if so, its clinical significance, by comparing it with two other types of gastrojejunostomy commonly used for gastric bypass in unresectable periampullary cancer.

METHODS

Forty-five patients with unresectable periampullary cancer complicated by gastric outlet obstruction (GOO) were recruited into this study between May 1992 and November 1995. They were randomized to receive one of the three types of gastrojejunostomy. The anastomosis in type I gastrojejunostomy was performed at the jejunum 20 cm distal to the ligament of Treitz. Type II was similar to type I except that in type II a duodenum partition was done by linear stapler 1 cm beyond the pylorus. Type III gastrojejunostomy was performed at the Roux-limb jejunum 60 cm distal to biliojejunostomy.

RESULTS

"Food reentry" was noted in three (21%) of the type I patients, as determined by upper gastrointestinal (UGI) study. Of the three, one patient had severe circulus vomiting, one had anorexia, and one had no major symptoms. When patients were evaluated immediately after oral diet intake resumed, the incidence (27%) of clinical GOO symptoms and mean value of gastric emptying time (GET1/2, 118.1 +/- 39.2 min) were significantly lower in type II patients than in types I and III patients. When evaluated I month after operation, the incidence (7% and 17%, respectively) of clinical symptoms of GOO and mean value of GET1/2 (42.0 +/- 23.0 and 35.6 +/- 5.4 min, respectively) were significantly lower in both type II and type III patients than in type I patients. The type II patients resumed oral diet after operation 3.5 days earlier than type I patients, p < 0.05.

CONCLUSIONS

Circulus vomiting induced by food reentry does exist if the gastrojejunostomy is performed as the type I gastrojejunostomy in this study. The newly designed type II gastrojejunostomy with duodenal partition is an easy, safe, and effective gastric bypass and avoids the problem of food reentry.

Peritoneal dialysis solution induces apoptosis of mesothelial cells

For better simulation of the long-dwell exchanges in conventional CAPD, we have developed a modified mesothelial cell culture system consisting of a Transwell culture apparatus. The equilibration patterns of pH, dextrose and osmolality in the present culture system were observed to be very similar to those in human CAPD. The effects of six different peritoneal dialysis solutions on the apoptosis of mesothelial cells were evaluated using this modified culture system. The results imply that peritoneal dialysis solution per se may incite apoptosis of mesothelial cells, and also that low calcium peritoneal dialysis solution is a milder apoptosis stimulant as compared to the conventional peritoneal dialysis solution. Moreover, varying concentrations of dextrose in the peritoneal dialysis solution were not observed to significantly affect the apoptosis rate. The roles of ambient high concentrations of calcium and dextrose, low pH, as well as high osmolality in the apoptosis are also discussed.

The interaction between human cytomegalovirus immediate-early gene 2 (IE2) protein and heterogeneous ribonucleoprotein A1

Human cytomegalovirus (HCMV) is an ubiquitous pathogen which causes significant illness in immunocompromised individuals. The immediate-early gene 2 (IE2) protein of HCMV plays an important role in the regulation of virus replication. Previous studies have shown that the IE2 protein is able to interact with several cellular proteins, but many of the IE2 interacting partners remain unidentified. By utilizing the yeast two-hybrid system, the heterogeneous ribonucleoprotein A1 (hnRNP A1) was identified as an IE2 interacting protein. The interaction was confirmed via the in vitro binding of bacterial expressed glutathione S-transferase (GST) IE2 fusion protein with the in vitro translated hnRNP A1. The mutational analysis showed that both the N-terminal half (1-290 residues) and C-terminal half (291-579 residues) of IE2 protein can interact with the hnRNP A1, indicating that more than one region of IE2 protein are involved in the binding with hnRNP A1.

Human stomach alcohol and aldehyde dehydrogenases: comparison of expression pattern and activities in alimentary tract

BACKGROUND & AIMS

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are the major enzymes responsible for ethanol metabolism in humans. The human stomach has been documented to be involved in the metabolism of first-passed alcohol. The aim of this study was to determine ethanol-metabolizing activities in the stomach with regard to sex, age, enzyme pattern, and polymorphism.

METHODS

A total of 209 surgical gastric mucosal specimens were investigated. The expression patterns of ADH and ALDH were identified by isoelectric focusing, and the activities were assayed spectrophotometrically.

RESULTS

At 33 or 500 mmol/L ethanol, pH 7.5, the activities in the ADH3 1-1 phenotypic and mu-ADH-expressing mucosal specimens were significantly greater than that in the ADH3 1-2 phenotypic and mu-ADH absent mucosal specimens, respectively. The activities of the ALDH2-inactive phenotypes were significantly lower than that of the ALDH2-active phenotypes at 200 micromol/L acetaldehyde. The gastric ADH and ALDH activities were not significantly different between men and women with respect to age and genetic polymorphism.

CONCLUSIONS

The stomach may contribute only a small portion of the alcohol metabolism observed in humans, and the liver may be the major site for first-pass metabolism. Differential expression patterns of ADH and ALDH in the alimentary tract suggest that different vulnerabilities to ethanol-induced mucosal injury may exist.

Prognostic factors affecting long-term survival after partial hepatectomy for human hepatocellular carcinoma

BACKGROUND

Various prognostic factors have been studied during the past few years to predict early tumor recurrence and survival in patients undergoing hepatectomy for primary hepatocellular carcinoma. However, the relationship between these factors and long-term survival has not been clarified. The purpose of this study was to identify the factors linked to long-term prognosis in patients with resectable hepatocellular carcinoma after hepatectomy.

METHODS

Records of 370 patients undergoing curative hepatectomy during a period from July 1981 to July 1994 were retrospectively reviewed. Only 110 patients with disease-free survival > or = 36 months were eligible for long-term survival analysis. Their further outcomes, including disease-free survival and overall survival, were analyzed in correlation with various prognostic factors by Kaplan-Meier's method, log rank test; and Cox's regression model. Analysis of prognostic factors linked to early tumor recurrence after curative hepatectomy was also performed in 324 patients who were followed up > or = 12 months.

RESULTS

Tumor behaviors were found to be the principal prognostic factors determining the early tumor recurrence and patients' survival (p < 0.05). However, when long-term survival was analyzed, the pathological status of the liver remnant such as the presence or absence of hepatitis B virus infection, chronic active hepatitis, hepatocyte dysplasia and age (< or = 60 y/o vs. > 60 y/o), as well as preoperative liver function (total serum bilirubin < or = 1.5 mg/dl vs. > 1.5 mg/dl), were found to make significant disease-free survival differences (p < 0.05), whereas the factors linked to tumor behaviors and surgical factors showed no influence on long-term prognosis.

CONCLUSIONS

Pathological status and host factors (age and liver function) have effect upon long-term prognosis after hepatic resection for hepatocellular carcinoma.

Diagnostic laparoscopy: indication and benefit

BACKGROUND

Patients with an obscure and unrelievable abdominal condition may be forced to receive open laparotomy for diagnosis. Diagnostic laparoscopy has been suggested as an alternative to diagnostic laparotomy in selected cases. The aim of this article is to evaluate the circumstances suitable for laparoscopic diagnosis of certain abdominal conditions and the possible advantages of that approach.

METHODS

Among 256 patients undergoing elective laparoscopic operations using conventionally pneumoperitoneal techniques from January 1994 to June 1995, twenty patients received diagnostic laparoscopy. The correlation between preoperative diagnosis, laparoscopic diagnosis and pathologic diagnosis as well as the outcome of laparoscopic diagnosis and treatment have been assessed.

RESULTS

Major indications for diagnostic laparoscopy included acute abdominal pain (n = 4), chronic abdominal pain (n = 6), differentiating intraabdominal tumor (n = 4), staging known malignancy (n = 3) and evaluating intraperitoneal implantation (n = 3). Two of the four patients with acute abdominal conditions, one of the six patients with chronic abdominal pain. Four of the seven patients with undifferentiated/unstaged abdominal tumors and all of the three patients with intraperitoneal-implanted drainage tubes had no reasons for a further exploratory procedure, thus preventing the morbidity or mortality which might occur after unnecessary laparotomy. The duration of operation and hospitalization was shorter than the group without laparotomy.

CONCLUSIONS

Diagnostic laparoscopy benefits patients by avoiding unnecessary surgery, avoiding unnecessary delay in diagnosis and treatment and shortening the operative and hospitalized period. However, it provides only an alternative not a substitute for traditional diagnostic procedures and will never lessen the importance of conventional laparotomy.

Is gastric remnant cancer clinically different from primary gastric cancer?

BACKGROUND/AIMS

Poorer survival, uncertain etiology and a possible surgically induced carcinoma prompted the question of whether the gastric remnant cancer is a special form of gastric carcinoma. A retrospective study was done to see if gastric remnant cancer is clinically different from primary gastric cancer without consideration of its etiology.

MATERIALS AND METHODS

There are 77 patient with gastric remnant cancer diagnosed in our hospital in past 15 years. Thirty-two out of 77 patients underwent gastrectomy. Another 536 patients with primary gastric cancer and 73 patients with proximal third gastric cancer were used as the controls. The clinicopathological characteristics including gender, age, TNM tumor stage, Lauren's classification, degree of tumor cell differentiation, rate of curative resection and 5-year survival rate were analyzed to see if there is significant difference among the three groups.

RESULTS

Almost 90% of patients with gastric remnant cancer had a partial gastrectomy with Billroth II operation before and the median incubation interval was 24.5 years. Male predominance in gastric remnant cancer was shown in our series. However, the age distribution, TNM tumor stage, Lauren's classification, degree of tumor cell differentiation, rate of curative resection and 5-year survival after curative resection were no different among the three groups.

CONCLUSIONS

There was no difference in clinical behavior of resected gastric remnant cancer from other gastric carcinoma. Since most of the tumors were detected too late to be resected, early detection is the only way to increase the resection rate and improve the survival. Annual endoscopic surveillance after gastrectomy was recommended for early detection.

Novel patterns of p53 abnormality in breast cancer from Taiwan: experience from a low-incidence area

Among 114 breast cancers in Taiwan, the prevalence of p53 mutation (22.8%) and p53 accumulation (38.3%) was similar to that in high-incidence areas. However, novel patterns of p53 abnormalities, including unique sites or types of mutation (i.e. an excessive proportion of G:C to A:T transition at CpG site), and accumulation of wild-type p53 either within nuclear or cytoplasmic compartments were noted. These may have relevance to breast cancer in Taiwan, a low-incidence area.

A case-control study of breast cancer in Taiwan--a low-incidence area

To investigate risk factors for breast cancer in Taiwan, a low-incidence area, a case-control study was conducted. This comprised 244 subjects with diagnosed and pathologically confirmed breast cancer (age range 20-80 years) and 450 female ophthalmology outpatients as controls. Univariate and multiple logistic regression analysis suggests that breast cancer in Taiwan is aetiologically similar to breast cancer in high to moderate-incidence areas. A family history of breast cancer appears to be the most important factor contributing to the risk of breast cancer (odds ratio = 4.69). The effect of reproductive hormones (represented by the years of history of menses in premenopausal women, odds ratio = 3.35; or the age at menarche in post-menopausal women, odds ratio = 2.67) plays a significant role in tumorigenesis. Breast feeding appears to be a particularly important protective factor in Taiwanese women (odds ratio = 0.57).

Sulphonylureas reverse hypoxia induced K(+)-conductance increase in substantia nigra pars reticulata neurones

Membrane potentials were recorded from neuronal somata in the substantia nigra pars reticulata of the rat midbrain slice using the whole-cell patch-clamp technique. Hypoxia induced a consistent decrease in input resistance often accompanied by membrane hyperpolarization and cessation of firing. The membrane hyperpolarization was mediated by K+ as indicated by its reversal potential at -88 +/- 9 mV, which is close to the equilibrium potential of K+. The hypoxic response was not sensitive to 1 microM tetrodotoxin or superfusion with Ca2(+)-free medium. While glibenclamide at 30 microM and tolbutamide at 300 microM had no effect on the resting membrane properties of the neurones, these sulphonylureas reversed the hypoxia-induced membrane hyperpolarization and restored firing. Inclusion of 2 mM of ATP in the recording pipette also prevented the hyperpolarization. These observations suggest that post-synaptic ATP-sensitive potassium channels exist on the GABA neurones of SNR and that these channels are activated in energy-depleting conditions exemplified by hypoxia.

Clinicopathological significance of intestinal and diffuse types of gastric carcinoma in Taiwan Chinese

The present study sought to evaluate the clinicopathological features of our gastric cancer patients in terms of a modified Lauren's histological classification and compared the results with those from studies from Japan and Western countries. A total of 536 consecutive patients with gastric cancer were treated surgically between December 1987 and December 1993. A clinicopathological analysis was only performed for intestinal types (IT) and diffuse types (DT) of gastric cancer because patients falling into the 'other' category were too small to produce meaningful data. Of 536 cases of gastric cancer, 268 (50%) were IT, 231 (43.1%) were DT and 37 (6.9%) were of the other type. The overall IT:DT ratio was 1.2. Gastric cancer patients with IT (in contrast to DT) were characterized by older age, male dominance, smaller tumours, the tumour often being located in the lower and upper third of the stomach and less peritoneal metastasis. In both sexes, the peak incidence of gastric cancer patients was in the age group 65-74 years. Men had higher proportions of IT carcinoma than women. The IT:DT ratio for men and women was 1.4 and 0.4, respectively. Although the increased ratio of IT:DT paralleled the advance of age in both sexes, the transitional age (the age at which the IT:DT ratio exceeds 1.0) in male patients (age group 51-64 years) was earlier than for female patients (age group 65-74 years). Patients with IT gastric cancer had a significantly better survival rate than those with DT. However, the type of carcinoma (IT or DT) was not an independent predictor of survival. These data indicate that gastric cancer in Taiwan Chinese has different biological behaviour in terms of IT and DT. The clinicopathological features in IT and DT carcinoma are similar to studies from Japan and from Western countries.

A prospective randomised study of laparoscopic v. open cholecystectomy in aged patients with cholecystolithiasis

Between August 1992 and July 1993, 27 patients aged 70 years of older with cholelithiasis were prospectively randomised into 2 groups. Fifteen patients underwent laparoscopic cholecystectomy and 12 patients underwent open cholecystectomy. Shorter operation time (93.3 +/- 25.3 minutes v. 176.3 +/- 26.1 minutes, P < 0.00001), fewer postoperative analgesic requirements (0.53 +/- 0.52 days v. 2.00 +/- 0.74 days, P < 0.00001), shorter postoperative hospital stay (3.93 +/- 1.71 days v. 7.92 +/- 0.79 days, P < 0.00001) and better cosmesis were found in the laparoscopic cholecystectomy group. The above data suggest that laparoscopic cholecystectomy is the treatment of choice for cholecystolithiasis in elderly patients.

Surgical resection of primary hepatocellular carcinoma extending to adjacent organ(s)

Primary hepatocellular carcinoma (HCC) extending to the adjacent organ(s) is sometimes encountered in patients with large, peripherally located tumours. Over a 4-year period, a total of 151 patients received curative resection of HCC at the Surgical Department of Veterans General Hospital-Taipei, Taiwan. Of these patients, 21 underwent hepatic resection combined with en-bloc resection of the adjacent organ(s) because tumour extension was found during operation. Subsequent histological examination of the resected specimens found evidence of HCC invasion into the resected adjacent organ(s) in only nine patients (group I), and the remaining 12 patients showed no evidence of extrahepatic HCC invasion (group II). Twenty-seven HCC patients with clinico-pathologically matched tumours but without extrahepatic extension were selected as controls (group III). One patient in group I died of hepatic failure after the operation. The morbidity rate was 48% in group I and group II patients, and 30% in group III patients. The difference was not statistically significant. On evaluating the clinico-pathological factors, including DNA ploidy status of the tumours, there were no significant differences between tumours with and without extrahepatic invasion. Patients with locally invasive HCC (group I) had disease-free and overall survival rates comparable with those of the patients without local tumour invasion (group II and III). We conclude that HCC with invasion to the adjacent organ(s) does not seem to be directly related to the 'aggressiveness' of the tumour, and extrahepatic infiltration of the tumour does not preclude a chance of cure. Our results underscore the need for en-bloc resection as treatment of choice for these patients.

Heat shock and cytokines modulate the expression of adhesion molecules on different human gastric-cancer cell lines

In order to understand the expression and modulation of adhesion molecules (AMs) on the surface of different gastric cancers, we studied 4 gastric-cancer cell lines including SC-M1, KATO-III, AGS and AZ-521. The expression of E-cadherin, integrins (beta1, beta2 and beta3), ICAMs (1 and 2), and CD11 (a, b and c) on the cells was detected by flow cytometry. We found that E-cadherin was only expressed on SC-M1 and KATO-III. CD29 (beta1 integrin) could be found in cells of all 4 lines. CD54 (ICAM- 1) could not be detected in AZ-521. In contrast, CD18 (beta2 integrin), CD61 (beta3 integrin), ICAM-2, CD11a, CD11b and CD11c were all absent from these cells. Heat-shock treatment (42.5 degrees C, 60 min) enhanced the expression of E-cadherin, CD29 and CD54 on SC-M1, and of CD29 on AGS. In addition, TNF-alpha (50U/ml) and IL-1beta (10U/ml) modulated the expression of these AMs, like heat-shock treatment. The increment of these adhesion molecules caused by heat shock, TNF-alpha and IL-1beta stimulation on SC-M1 was also confirmed by Western blot analysis. Functionally, these treatments increased the binding between normal human mononuclear cells and SC-Ml cells. The heat-shock treatment could induce a significant amount of TNF-alpha and IL-1beta release from SC-M1 and KATO-III, but seemed irrelevant to the expression of AMs. These results suggest that limited adhesion molecules were expressed on the surface of different gastric cancer cells. Heat shock, IL-1beta and TNF-alpha may selectively modulate the expression of these 3 molecules on some of the cells, and this is probably related to their antitumor effect.

Surgical management of primary retroperitoneal sarcoma

BACKGROUND

Retroperitoneal sarcoma is a rare and challenging group of diseases for surgeons, characterized by extensive growth and high recurrent rate. We analyzed data from our patients to identify the factors of survival.

METHODS

From 1971 to 1993, medical records of 40 patients with primary retroperitoneal sarcoma were reviewed. Clinical factors including age, sex, tumor size, histopathology, type of operation, disease-free interval, and number of operation were collected to correlate with patient's survival.

RESULTS

Most patients presented with huge abdominal mass. There were 22 liposarcomas, 8 leiomyosarcomas, 5 malignant fibrous histiocytomas, 2 fibrosarcomas, 2 malignant mesenchymomas and one rhabdomyosarcoma. Twenty-eight patients received complete resection and 12 had incomplete resection. The group with complete resection showed a better survival than incomplete resection group (p = 0.0001). Nineteen patients with complete resection had tumor recurrence. The recurrent rate was 68%. Patients having been disease-free for more than 12 months showed to have better survival than those less than 12 months (p = 0.005). Aggressive surgical resection was done in case of tumor recurrence. Patients who received more than 2 (> or = 3) operations also showed a better survival than those with less than 2 operations (p = 0.0247).

CONCLUSIONS

Complete surgical resection and aggressive repeated surgical intervention are the most effective treatment modality for better survival in patients with retroperitoneal sarcoma.

Results of curative gastrectomy for carcinoma of the distal third of the stomach

BACKGROUND

Carcinoma of the distal stomach metastasizes to lymph nodes along the bile duct, pancreatic head, and duodenum. We reviewed the results of patients who underwent operation for carcinoma of the stomach, and placed special emphasis on survival related to lymph node metastasis.

STUDY DESIGN

We conducted a prospective study of 258 consecutive patients with adenocarcinoma of the distal third of the stomach who underwent curative gastrectomies.

RESULTS

Most of the patients (193 [75 percent]) had advanced cancer (extension beyond the submucosa). A subtotal gastrectomy was the procedure most commonly performed (89 percent). Combined organ resection was performed in 100 patients (39 percent). The operative morbidity was 17 percent; the most frequent complications were chylous leakage, anastomotic insufficiency, and intra-abdominal infection. Ninety-four patients (36 percent) had tumor recurrence, with local recurrence occurring in 45 patients. In 40 of the 45 cases, the local recurrence resulted from remnant lymph nodes (LNs), or soft tissues in the gastric bed. Lymph node metastases were observed in 152 patients (59 percent). Excluding five patients (2 percent) who died, the overall five-year cumulative survival rate was 53 percent. The five year survival rate was 98 percent for patients with TNM stage I disease; 68 percent for patients with stage II disease; 40 percent for patients with stage III disease; and 10 percent for patients with stage IV disease. The survival rate for patients with n0, n1, n2, and n3 disease was respectively 92 percent, 45 percent, 30 percent, and 20 percent. For patients with metastatic LNs in the hepatoduodenal ligament, the five-year survival rate was 20 percent.

CONCLUSIONS

These data suggest that survival rate relates to the extent of LN metastasis. It appears that systematic lymph node dissection may have a beneficial effect. However, the efficacy of radical lymph node dissection can only be determined by prospective, randomized clinical trials with a proper study design.

The surgical treatment and prognostic factors of well-differentiated thyroid cancers in Chinese patients: a 20-year experience

BACKGROUND

Well-differentiated thyroid cancers (WDTC) are usually slow-growing neoplasm with an indolent clinical course. Assessment of treatment modalities for them requires a long-term follow-up in a large population, and is still of much debate. A systematic analysis of the history, prognosis and therapy for this disease in Taiwan is lacking.

METHODS

A retrospective analysis of clinical and pathological records was conducted on 488 patients (149 male and 339 female, male: females = 1:2.28) treated for WDTC in the Veterans General Hospital-Taipei from 1971 to 1991 with subsequently follow-up until December 1994 (Mean follow-up: 8.5 years). Factors influencing recurrence, survival and different treatment were analyzed.

RESULTS

Papillary thyroid cancer increased obviously as compared to our experience from 1959-1976. Changing tumor behaviors, including increasing female/male ratio, higher percentage of papillary cancer, decreasing primary tumor size and lower distant metastatic rate at the time of initial diagnosis, were noted. Factors influencing survival, as determined by univariate analysis, included age, gender, distant metastasis, extrathyroidal invasion, tumor size, nodal involvement, histological type, extent of surgical therapy and use of postoperative radioactive iodine. Those patients aged more than 45 at initial diagnosis, with primary tumors larger than 4 cm, with extrathyroidal invasion, and with distant metastasis at initial diagnosis were classified as being at high risk. The others were at low risk. Total or near total thyroidectomy (TTx), depending on the judgement of each surgeon, had much higher complication rate than lobectomy with/without isthmusectomy, but offered no benefit effect on disease-free survival or overall survival rates. Postoperative radioactive iodine ablation treatment and thyroxine replacement in suppressive dose after TTX improved survival among high risk patients. Lobectomy with/without isthmusectomy in low risk patients, followed by thyroxine suppression therapy, was adequate to improve the postoperative outcome and with low complication rate. Lymph node resection in patients with clinically palpable nodes improved longterm prognosis.

CONCLUSIONS

Changing tumor behavior of WDTC leading to favorable prognosis has been noticed since 1971. Total or near total thyroidectomy is worthwhile in high risk patients with WDTC but does not appear necessary in low-risk patients. Lymph node dissection for metastatic lymph node could improve the survival rate.

Immunohistochemical study of arginase in cancer of the stomach

High levels of arginase have been detected in gastric adenocarcinoma. To examine the hypothesis that this is due to macrophage infiltration into the tumour, we localized the cellular distribution of arginase by immunohistochemical staining. We examined gastric adenocarcinomas and their corresponding normal tissues (n = 45), leiomyomas (n = 2), leiomyosarcomas (n = 3), human gastric adenocarcinoma cell lines (n = 3), and benign gastric ulcers (n = 4) by the avidin-biotin-peroxidase complex technique. Macrophages with strong arginase immunoreactivity were observed infiltrating both gastric normal and cancer tissues. No arginase immunoreactivity was observed in normal mucosal gland, muscular and serosal tissues or benign gastric ulcers. The immunoreactivity of arginase was positive but heterogeneous in most specimens of gastric adenocarcinoma (62.2%) and was absent from gastric intestinal metaplasia, leiomyomas and leiomyosarcomas. Among the 28 neoplasms with arginase immunoreactivity, scattered immunoreactivity was also noted in adjacent dysplastic glands in 12 (42.8%) specimens. Arginase immunoreactivity was observed in all three gastric cancer cell lines. Arginase is present in the cytoplasm but not in the nucleus. These data suggest that the high arginase levels in adenocarcinoma cancer tissues originate largely from cancer cells.

Serum interleukin-6 levels reflect disease status of gastric cancer

OBJECTIVES

Interleukin-6 (IL-6) has been shown to be associated with cancer development. However, its role in gastric cancer patients has never been investigated. Our intent was to investigate this role.

METHODS

Using enzyme-linked immunosorbent assay, we determined the IL-6 levels in sera of patients with gastric cancer (n = 218), benign gastric lesions (n = 9), and hepatitis B (n = 9), and in normal subjects (n = 85). C-reactive protein (CRP) levels and Helicobacter pylori antibodies were simultaneously determined in 150 and 133 gastric cancer patients, respectively. Serial serum IL-6 levels were also measured in 14 gastric cancer patients. Six gastric cancer cell lines were examined for IL-6 secretion. For comparison, serum carcinoembryonic antigen levels in all gastric cancer patients were also determined.

RESULTS

Mean IL-6 levels were significantly higher in patients with gastric cancer (10.0 +/- 9.5 pg/ml) than in patients with benign gastric lesions (2.6 +/- 0.5 pg/ml), in hepatitis B carriers (2.8 +/- 0.9 pg/ml), and in normal subjects (2.5 +/- 0.3 pg/ml). Gastric cancer patients with IL-6 > 10 pg/ml increased in a stage-related manner (p = 0.0001). Serum IL-6 levels increased when four patients had recurrence, whereas IL-6 levels decreased in 10 patients with a disease-free status after gastric resection. Serum IL-6 levels correlated moderately with serum CRP levels (r = 0.5, p < 0.01), but not with H. pylori antibody titers (p = 0.23). Serum IL-6 levels correlated with survival, but not as an independent prognostic indicator. Conversely, patients with CEA > 5 ng/ml increased in a stage-related manner, but this is not an effective reflection of disease progression. Five of six gastric cancer cell lines secrete IL-6.

CONCLUSIONS

Serum IL-6 levels correlate with disease status of gastric cancer and may be used as a new tumor marker for monitoring treatment and response of gastric cancer patients.

Paclitaxel-induced apoptosis in human gastric carcinoma cell lines

BACKGROUND

Gastric cancer is one of the most common cancers in Asia. Chemotherapy and radiation therapy have had limited success. Recently, paclitaxel has been found to be effective against a variety of cancers, including lung, breast, ovary, melanoma, and prostate. Whether paclitaxel is effective in the treatment of gastric cancer is not known and is worthy of investigation.

METHODS

Human gastric carcinoma cell lines NUGC-3 and SC-M1 were examined for response to paclitaxel treatment. Cancer cells were treated with paclitaxel (0.001, 0.01, 0.1, and 1 microM) for 1-3 days. Cell number was counted by hemocytometer and cell viability was determined by the trypan blue exclusion method. Cell cycle progression and expression of proliferating cell nuclear antigen (PCNA) were examined by flow cytometry. The percentage of apoptotic cells was determined after staining with hematoxylin and eosin.

RESULTS

Paclitaxel was cytotoxic to the two human gastric carcinoma cell lines examined. The growth-inhibiting dose was 0.01 microM. Paclitaxel-treated gastric carcinoma cells were arrested mainly in G2/M phases before apoptosis. However, treatment with 0.01 microM of paclitaxel resulted in a decrease of cells at G0/G1 phases without an increase of cells at G2/M phase indicating that paclitaxel was also cytotoxic to gastric carcinoma cells at G0/G1 phases. In addition, the expression of PCNA was significantly increased in 0.1 and 1 microM paclitaxel-treated cells, suggesting that DNA repair was increased in these cells.

CONCLUSIONS

Paclitaxel is effective in growth inhibition of gastric carcinoma cell lines in clinically attainable concentrations. Our results suggest that paclitaxel is a potential chemotherapeutic drug for gastric carcinoma.

Relationship between age and clinical characteristics of patients with gastric cancer

The relationship between the prognosis and age of patients with gastric cancer is controversial. To evaluate whether there is a biological characteristic specific to the age of patients, we examined the clinical characteristics of patients with gastric cancer with special reference to their age. Based on a prospective database, a retrospective study of 419 patients who underwent radical gastrectomy for cure in the past 6 years was conducted. Clinical characteristics including gender, gross appearance of the tumour (Borrmann's classification, tumour location), histopathology (depth of tumour invasion, lymph node status, Lauren's classification and degree of tumour cell differentiation) and TNM tumour stage were analysed in six different age groups (< 39, 40-49, 50-59, 60-69, 70-79, > 80 years). The mean age of the 419 patients was 64.6 years (range from 26-91) and the peak age incidence of gastric cancer (46.3%) was in the 60-69 year old age group. The male: female ratio was 4.6:1 on the whole and male gender predominated at ages > 60. The proportion of diffuse type tumours (68.4%) by Lauren's criteria in the young age group (< 39 yrs) decreased with age (25% in the > 80 years group; P < 0.001). Similarly, the proportion of poorly-differentiated tumours (89.5%) in the young age group (< 39 yrs) decreased with advancing age (P < 0.001). These findings suggest that both diffuse type and poorly-differentiated tumours predominate in younger patients and, without considering the factor of delay in diagnosis, may explain the poorer prognosis demonstrated in younger patients.