颅咽管瘤临床和病理特征的关系

对７０例颅咽管瘤的病理组织学特征和临床关系进行分析讨论，发现鳞状乳头型和造釉细胞型两种颅咽管瘤在临床方面有各自的特点，前者成人多见，肿瘤钙化少，以实质性肿瘤多见，其内分泌功能障碍发生率比后者高。造釉细胞型肿瘤多见钙化和囊性变，其视力、视野损害发生率比前者高。同时对肿瘤的病理特征与手术效果、临床预后之间的关系作了分析。

Vascular Calcification:Where is the Cure?

With the progress of aging,the incidence of vascular calcification(VC)gradually increases,which is correlated with cardiovascular events and all-cause death,aggravating global clinical burden.Over the past several decades,accumulating approaches targeting the underlying pathogenesis of VC have provided some possibilities for the treatment of VC.Unfortunately,none of the current interventions have achieved clinical effectiveness on reversing or curing VC.The purpose of this review is to make a summary of novel perspectives on the interventions of VC and provide reference for clinical decision-making.

中青年脑梗塞患者的临床与病理

目的探讨中、青年人脑梗塞的病因。方法将连续尸检确诊的脑梗塞病例中≤４５岁患者的脑标本常规处理，以动脉为重点行肉眼及光镜下观察，并分析有关临床资料。结果７２例患者中≤４５岁者７例，其中男６例，女１例。其中高血压、风湿性心脏病各２例，嗜烟、嗜酒各４例，病前１日酗酒１例。梗塞灶相关动脉闭塞处管壁５例发现粥样斑块，３例发现炎症（１例与粥样斑并存）。５例粥样斑块血栓形成均位于基底动脉，４例病后２日内死亡；未发现动脉硬化的２例为左侧大脑中动脉闭塞，病后存活１周以上。４例有脑疝形成。无一例发现明确的并发症。结论在中青年脑梗塞患者，早发性动脉粥样硬化是其重要病因之一，烟酒可能是其危险因素之一；动脉闭塞的部位是决定首次发病后存活时间的重要因素；脑源性死亡是致死的根本原因。

Binswanger病的临床病理观察

目的探讨Ｂｉｎｓｗａｎｇｅｒ病的病理基础及发病原因。方法对９例老年人Ｂｉｎｓｗａｎｇｅｒ病及１３例非痴呆老年对照组的尸检材料进行临床、病理组织形态学，免疫组化及测微观察。结果Ｂｉｎｓｗａｎｇｅｒ病组的病灶主要位于皮质下白质、侧脑室周围、内囊、基底节、甚或累及脑干及小脑；其病理基础为脱髓鞘、微小腔隙性梗死灶、胶质细胞增生及血管周围间隙扩大，脑白质深穿支小动脉壁明显增厚（１９．５０μｍ±４．３１μｍ），与对照组（６．２５μｍ±５．１３μｍ）比较差异有显著性，均为Ｐ＜０．０１。结论Ｂｉｎｓｗａｎｇｅｒ病并不少见；慢性高血压动脉硬化，脑缺血是Ｂｉｎｓｗａｎｇｅｒ病发病的重要因素。

儿童鼻部肿瘤的临床病理和影像学分析

目的:加深对儿童鼻部肿瘤的发病情况、临床病理组织学及影像学特点的全面了解,提高临床诊断和鉴别诊断水平。方法:收集经活检或术后病理确诊的40例鼻部肿瘤患儿的资料,总结其临床特征、病理组织学及影像学特点。结果:良性肿瘤23例,恶性肿瘤17例。良性肿瘤以纤维血管瘤(7例)、毛细血管瘤(4例)及骨化纤维瘤(4例)为主;恶性肿瘤以淋巴瘤(10例)及胚胎型横纹肌肉瘤(3例)为主。10例病变主要位于鼻窦,7例病变局限于鼻腔或鼻前庭,8例鼻腔鼻窦均受累,10例病变位于鼻咽部和(或)后鼻孔,3例位于外鼻,2例位于鼻中隔。CT或MRI表现:骨质破坏13例,骨质吸收5例,14例累及邻近结构,6例伴颈部淋巴结肿大。结论:儿童鼻部肿瘤以淋巴瘤、纤维血管瘤、毛细血管瘤、骨化纤维瘤和胚胎型横纹肌肉瘤较常见,其临床症状不典型,诊断及鉴别诊断主要依靠病理及影像学检查,CT和MRI能很好地显示肿瘤的部位、周围骨质改变情况和邻近结构侵犯,对肿瘤的临床诊断、分期、治疗方案的制定及预后评估具有重要意义。

In vitro Study of Interstitial Combination Chemotherapy in the Treatment of Glioma

Objective： To investigate the inhibitory effects of combination chemotherapy of Carboplatin （CBP）, Teniposide （Vm-26）, Methasquin （MTX）, and Nimodipine （NIM） on glioma, and to explore the sensitivity of glioma cells to different treatment regimens so as to provide some clues for clinical usage of interstitial combination chemotherapy. Methods： MTT assay and 3H-TdR incorporation assay were performed to evaluate the inhibitory effects upon the proliferation of glioma cells, and to compare the sen- sitivity of glioma cells to administration of CBP, Vm-26, MTX, and NIM with that of the administration of CBP＋NIM, Vm-26＋NIM, MTX＋NIM, CBP＋Vm-26＋MTX, or CBP＋Vm-26＋MTX＋NIM, respectively. Results： The inhibition rate of CBP＋Vm-26＋MTX＋NIM combination administration against glioma cells was 96.64%, higher than that of CBP＋NIM （69.03%）, Vm-26＋NIM （71.53%）, MTX＋NIM （52.75%）, CBP＋Vm-26＋MTX （78.59%） （P〈0.01）, and the dosage of CBP, Vm-26, and MTX was declined to 1/10- 1/100 that of respective use of CBP, Vm-26, and MTX. Conclusion： The curative effect of combination administration of CBP, Vm-26, MTX, and NIM was much better than that of respective administration, suggesting a higher inhibition rate and a lower dosage use.

Clinical Study of Photodynamic Therapy for Upper Gastrointestinal Tract Cancers

Objective： To evaluate the clinical effectiveness and adverse effects of photodynamic therapy （PDT） for the upper gastrointestinal tract cancers. Methods： 56 patients with upper gastrointestinal cancers in different clinical stages were treated with PDT. Diode laser （630 nm） was used as the light source and the parameters were as follows： power density 200 to 400 mW/cm, energy density 100 to 300 J/cm. PHOTOFRIN was used as photosensitizer, which was given in a dose of 2 mg/kg intravenously 12-24 h before irradiation. Results： Evaluation of the 56 patients＇ therapeutic effectiveness showed that 6 patients （10.7%） had a complete response （CR）, 33 patients （58.9%） partial response （PR）, 12 patients （21.4%） mild response （MR）, and 5 patients （8.9%） no response （NR）. The total response rate （CR＋PR） was 69.6%. No patients had severe adverse effects in this group. Conclusion： PDT is an effective and safe palliative modality for upper gastrointestinal tract cancers.

Expression of Angiopoietin-2 and Vascular Endothelial Growth Factor in Oral Squamous Cell Carcinoma and Its Significance

Objective： To investigate the expression of angiopoietin-2 （Ang-2） and vascular endothelialcell growth factor （VEGF） in oral squamous cell carcinoma （OSCC） and their correlations with clinicopathologic parameters, angiogenesis and vessel maturation of OSCC. Methods： The expression of Ang-2 and VEGF was detected in 41 speciments of human OSCC, 30 adjacent noncancerous oral tissues and 10 specimens of normal oral mucosa by conventional immumohistochemistry. Microvessel density （MVD） and vessel maturation index （VMI） were also assessed by double-labelling immumohistochemistry staining against CD34, a marker of pan-endothelial cells, and that against alpha-smooth muscle actin （α-SMA）, a marker of mural cells （pericytes/smooth muscle cells）. Results： The positive expression rate of Ang-2 and VEGF in 41 OSCC tissues was 51.22% and 63.42%, respectively. The expression of Ang-2 and VEGF was significantly higher in OSCC than in adjacent noncancerous oral tissues （all P〈0.05） and normal oral mucosa （all P〈0.05）. In the clinicopathologic parameters, the Ang-2 expression was closely correlated with tumor lymph node metastasis （P〈0.01） and the VEGF expression was correlated with tumor differentiated degree （P〈0.05）, but there was no significant correlation among the Ang-2 and VEGF expression and patients＇ sex, age and TNM stages （all P〉0.05）. The MVD of OSCC positive for both Ang-2 and VEGF was significantly higher than that of OSCC negative for both Ang-2 and VEGF （P〈0.05）. The VMI of OSCC positive for Ang-2 was significantly lower than that of OSCC negative for Ang-2 （P〈0.05）. When Ang-2 expression was combined with the staus of VEGF expression, MVD of OSCC positive for both Ang-2 and VEGF was the highest （51.08±2.99） as compared with that of other status in patient with OSCC （all P〈0.05）. Conclusion： The overexpression of Ang-2 and VEGF may play a crucial role in the development of OSCC. They are closely associated with angiogenesis and vessel maturation of tumor.

The Establishment and Characterization of a Continuous Cell Line of Mouse Cervical Carcinoma

OBJECTIVE To establish a murine uterine cervical cancer cell line and to define its biological characters. METHODS Transplanted tumor tissue was used for in vitro primary culture of U14 cervical carcinoma cells. After 20 passages, we examined its morphology, chromosomes, tumorigenicity and produced a growth curve. CK was detected by immunohistochemistry, the cell cycle determined by flow cytometry and the metastatic potential assessed in 615 and C57BL/c mice. We also transfected the cells with the pEGFP-N1 plasmid. RESULTS A newly established murine cell line was passaged 50 times over a period of 10 months. The cells grow as a partially suspended culture, and are immunohistochemically CK（＋）. The cell line is characterized by a hypotetraploid karyotype, a chromosomal number of 64-68 and a doubling time of 21.8 h. Exponential growth occurs by the third and forth day of culture. Cell cycle analysis showed G1 34%, G2 26%, and 40% in the S phase. The tumorigenicity was 100% upon implantation. No mycoplasma contamination was detected. A monoclonal continuous U14-GFP cell strain which was 100% GFP （＋） was also produced. CONCLUSION We successfully established a new murine cervical U14 carcinoma cell line and an U14-GFP monoclonal strain. These cell lines are ideal for combined in vivo and in vitro tumor research.

Management of hilar cholangiocarcinoma in the North of England: Pathology, treatment, and outcome

AIM: To assess the management and outcome of hilar cholangiocarcinoma (Klatskin tumor) in a single tertiary referral center.METHODS: The notes of all patients with a diagnosis of hilar cholangiocarcinoma referred to our unit for over an 8-year period were identified and retrospectively reviewed. Presentation, management and outcome were assessed.RESULTS: Seventy-five patients were identified. The median age was 64 years (range 34-84 years). Male to female ratio was 1:1. Eighty-nine percent of patients presented with jaundice. Most patients referred were under Bismuth classification 3a, 3b or 4. Seventy patients required biliary drainage, 65 patients required 152percutaneous drainage procedures, and 25 had other complications. Forty-one patients had 51 endoscopic drainage procedures performed (15 failed). Of these,36 subsequently required percutaneous drainage. The median number of drainage procedures for all patients was three, 18 patients underwent resection (24%), nine had major complications and three died post-operatively.The 5-year survival rate was 4.2% for all patients, 21%for resected patients and 0% for those who did not undergo resection (P = 0.0021). The median number of admissions after diagnosis in resected patients was two and three in non-resected patients (P＜0.05).Twelve patients had external-beam radiotherapy, seven brachytherapy, and eight chemotherapy. There was no significant benefit in terms of survival (P = 0.46) or hospital admissions.CONCLUSION: Resection increases survival but carries the risk of significant morbidity and mortality.Percutaneous biliary drainage is almost always necessary and endoscopic drainage should be avoided if possible.

Gastric malignancies in Northern Jordan with special emphasis on descriptive epidemiology

AIM:To study the epidemiology of gastric malignancies in Jordan as a model for Middle East countries where such data is scarce. METHODS:Pertinent epidemiological and clinicopathological data for 201 patients with gastric malignancy in north of Jordan between 1991 and 2001 were analyzed. RESULTS:Male:female ratio was 1.8:1.The mean age was 61.2 years,and 8.5% of the patients were younger than 40 years of age.The overall age-adjusted incidence was 5.82/100 000 population/year.The age specific incidence for males raised from 1.48 in those aged 30-39 years to 72.4 in those aged 70-79 years.Adenocarcinomas, gastric lymphomas,malignant stromal tumors,and carcinoids were found in 87.5%,8%,2.5%,and 2% respectively.There was an average of 10.1-month delay between the initial symptoms and the diagnosis.Only 82 patients underwent“curative”gastrectomy.Among adenocarcinoma groups,Lauren intestinal type was the commonest(72.2%)and the distal third was the most common localization(48.9%).The mean follow up for patients with gastric adenocarcinoma was 25.1 mo(range 1-132mo).The 5-year survival rates for stages Ⅰ(n=15), Ⅱ(n=41),Ⅲ(n=59),and Ⅳ(n=53) were 67.3%,41.3%, 5.7%,and 0% respectively(P=0.0001).The overall 5 year survival was 21.1%. CONCLUSION:Despite low inddence,some epidemiological features of gastric cancer in Jordan mimic those of high- risk areas.Patients are detected and treated after a relatively long delay.No justification in favor of a possible gastric cancer screening effort in Jordan is supported by our study;rather,the need of an earlier diagnosis and subsequent better care.

A clinical dilemma:abdominal tuberculosis

AIM:To evaluate the clinical,radiological and microbiological properties of abdominal tuberculosis (TB) and to discuss methods needed to get the diagnosis. METHODS:Thirty-one patients diagnosed as abdominal TB between March 1998 and December 2001 at the Gastroenterology Department of Kartal State Hospital, Istanbul,Turkey were evaluated prospectively.Complete physical examination,medical and family history,blood count erythrocyte sedimentation rate,routine biochemical tests, Mantoux skin test,chest X-ray and abdominal ultrasonography (USG) were performed in all cases,whereas microbiological examination of ascites,upper gastrointestinal endoscopy,colonoscopy or barium enema,abdominal tomography,mediastinoscopy,laparoscopy or laparotomy were done when needed. RESULTS:The median age of patients (14 females,17 males) was 34.2 years (range 15-65 years).The most frequent symptoms were abdominal pain and weight loss. Eleven patients had active pulmonary TB.The most common abdominal USG findings were ascites and hepatomegaly.Ascitic fluid analysis performed in 13 patients was found to be exudative and acid resistant bacilli were present in smear and cultured only in one patient with BacTec (3.2%).Upper gastrointestinal endoscopy yielded nonspecific findings in 16 patients.Colonoscopy performed in 20 patients showed ulcers in 9 (45%),nodules in 2 (10%) and,stricture,polypoid lesions,granulomatous findings in terminal ileum and rectal fistula each in one patient (5%). Laparoscopy on 4 patients showed dilated bowel loops, thickening in the mesentery,multiple ulcers and tubercles on the peritoneum.Patients with abdominal TB were divided into three groups according to the type of involvement. Fifteen patients (48%) had intestinal TB,11 patients (35.2%) had tuberculous peritonitis and 5 (16.8%) tuberculous lymphadenitis.The diagnosis of abdominal TB was confirmed microbiologically in 5 (16%) and histo- pathologically in 19 patients (60.8%).The remaining nine patients (28.8%) had been diagnosed by a positive response to antituberculous treatment. CONCLUSION:Neither clinical signs,laboratory,radiological and endoscopic methods nor bacteriological and histopathological findings provide a gold standard by themselves in the diagnosis of abdominal TB.However,an algorithm of these diagnostic methods leads to considerably higher precision in the diagnosis of this insidious disease which primarily necessitate a clinical awareness of this serious health problem.

Clinicopathological significance of expression of paxillin, syndecan-1 and EMMPRIN in hepatocellular carcinoma

AIM: To evaluate the relationship of expression of paxillin,syndecan-1 and EMMPRIN proteins with clinicopathological features in hepatocellular carcinoma (HCC).METHODS: Fifty-one patients who underwent HCC resection were recruited in the study. Paxillin, syndecan1 and EMMPRIN proteins in HCC tissues were detected with immunohistochemical staining.RESULTS: Of 51 cases of HCC, 23 (45%) exhibited paxillin protein positive expression. Of 42 cases of adjacent nontumor liver tissues, 24 (57%) exhibited positive expression.Positive paxillin protein expression was associated with low differentiation (r= 0.406, P= 0.004), with the presence of portal vein thrombosis (r = 0.325, P = 0.021), with extra-hepatic metastasis (r = 0.346, P = 0.014). Of 51cases of HCC, 28 (55%) exhibited syndecan-1 protein positive expression. Of 42 cases of adjacent non-tumor liver tissues, 23 (55%) exhibited positive expression.Positive snydecan-1 protein expression was associated with well differentiation (r = 0.491, P = 0.001), with no extra-hepatic metastasis (r = 0.346, P = 0.014). Of 51cases of HCC, 28 (55%) exhibited EMMPRIN protein positive expression. Of 42 cases of adjacent non-tumor liver tissues, 21 (50%) exhibited positive expression.Expression of EMMPRIN protein was not associated with serum AFP level, HBsAg status, presence of microsatellite nodule, tumor size, presence of cirrhosis and necrosis,differentiation, presence of portal vein thrombosis, extrahepatic metastasis, disease-free survival and overall survival (P＞0.05). Expression of paxillin protein was correlated conversely with the expression of syndecan-1protein in HCC (r = -0.366, P = 0.010).CONCLUSION: Expression of paxillin and syndecan-1proteins in HCC may affect its invasive and metastatic ability of the tumor. There may be a converse correlation between the expression of paxillin and syndecan-1 protein in HCC. Expression of EMMPRIN protein may be detected in HCC, but it may play little role in the invasion and metastasis of HCC.

Clinicopathological study on TTV infection in hepatitis of unknown etiology

AIM: To investigate the state of infection, replication site, pathogenicity and clinical significance of transfusion transmitted virus (TTV) in patients with hepatitis, especially in patients of unknown etiology. METHODS: Liver tissues taken from 136 cases of non-A non-G hepatitis were tested for TT virus antigen and nucleic acid by in situ hybridization (ISH) and nested-polymerase chain reaction (PCR). Among them, TT virus genome and its complemental strand were also detected in 24 cases of autopsy liver and extrahepatic tissues with ISH. Meanwhile, TTV DNA was detected in the sera of 187 hepatitis patients by nested-PCR. The pathological and clinical data of the cases infected with TTV only were analyzed. RESULTS: In liver, the total positive rate of TTV DNA was 32.4% and the positive signals were located in the nuclei of hepatocytes. In serus, TTV DNA was detected in 21.4% cases of hepatitis A-G, 34.4% of non-A non-G hepatitis and 15% of healthy donors. The correspondence rate of TTV DNA detection between liver tissue with ISH and sera with PCR was 63.2% and 89.3% in the same liver tissues by ISH and by PCR, respectively.Using double-strand probes and single-strand probes designed to detect TTV genome, the correspondence rate of TTV DNA detected in liver and extrahepatic tissues was 85.7%. Using single-strand probes, TTV genome could be detected in liver and extrahepatic tissues by PCR, but its complemental strands (replication strands) could be observed only in livers. The liver function of most cases infected with TTV alone was abnormal and the liver tissues had different pathological damage such as ballooning, acidophilia degeneration, formation of apoptosis bodies and focus of necrosis, but the inflammation in the lobule and portal area was mild. CONCLUSION: The positive rate of TTV DNA among cases of hepatitis was higher than that of donors, especially in patients with non-A non-G hepatitis, but most of them were coinfected with other hepatitis viruses. TTV can infect not only hepatocytes, but also extrahepatic tissues. However, the chief replication place may be liver. The infection of TTV may have some pathogenicity. Although the pathogenicity is comparatively weak, it can still damage the liver tissues. The lesions in acute hepatitis (AH) and chronic hepatitis (CH) are mild, but in severe hepatitis (SH), it can be very serious and cause liver function failure, therefore, we should pay more attention to TTV when studying the possible pathogens of so-called "liver hepatitis of unknown etiology".

Clinicopathological significance of FHIT protein expression in gastric adenocarcinoma patients

AIM： To investigate the expression of fragile histidine triad （FHIT） protein, and the possible relationship between FHIT expression and dinicopathological indices in gastric carcinoma. METHODS： FHIT protein expression was examined in 76 cases of gastric carcinoma, 58 cases of intraepithelial neoplasia, and 76 cases of corresponding normal mucosae by immunohistochemical method to analyze its relationship to histological grade, clinical stage, metastatic status and prognosis. RESULTS： The FHIT protein expression was positive in 28/76 （36.8%） cases of adenocarcinoma tissue, 22/58 （37.9%） cases of adjacent dysplastic tissue and 76/76 （100%） cases of distal normal gastric mucosa. There was a significant difference in the expression of FHIT protein between cancer or adjacent intraepithelial neoplasia and normal gastric mucosa （P = 0.000）. FHIT protein expression was found in 64.3% （18/28） of grades Ⅰ and Ⅲ cancers, and 20.8% （10/48） of grade Ⅲcancers （P = 0.000）, in 56.3% （18/32） of stages Ⅰ and Ⅱ cancers and 22.7% （10/44） of stages Ⅲ and IV cancers （P = 0.004）, and in 63.6% （14/22） of cancers without metastasis but only 25.9% （14/54） of those with metastasis （P = 0.003）. The significant difference in the expression of FHIT was found between histological grade, clinical stage and metastatic status of cancer. Follow-up data showed that there was a significant difference in median survival time between cancer patients with expression of FHIT （71 mo） and those without （33 mo, log rank = 20.78, P = 0.000）. CONCLUSION： FHIT protein is an important tumor suppressor protein. Loss of FHIT protein expression may be associated with carcinogenesis, invasion, metastasis and prognosis of gastric adenocarcinoma. 2005 The WJG Press and Elsevier Inc. All rights reserved

Expression and significance of Tie-1 and Tie-2 receptors, and angiopoietins-1,2 and 4 in colorectal adenocarcinoma:Immunohistochemical analysis and correlation with clinicopathological factors

AIM: There is strong evidence that tyrosine kinases are involved in the regulation of tumor progression, cellular growth and differentiation. Recently, many kinds of tyrosine kinase receptors have been reported, among them Tie-1 and Tie-2 receptors constitute a major class.Angiopoietin (Ang)-1 is known as a ligand ofTie-2 tyrosine kinase receptor. The objective of this study was to establish a comprehensive Tie-1 and Tie-2 and Ang-1, 2 and 4expression profile in human colorectal adenocarcinomas.METHODS: We examined 96 cases of surgically resected human colorectal adenocarcinoma by immunohistochemistry and investigated the statistical correlation between the expressions of Ties and Angs and clinicopathological factors.RESULTS: Among the 96 cases of adenocarcinoma, 87(90.6%), 92 (95.8%), 83 (86.5%), 89 (92.7%), and 76cases (79.2%) showed positive staining in the cytoplasm of carcinoma cells for the Tie-1 and Tie-2 and Ang-1, 2and 4 proteins, respectively. Histologically, the expressions of Ties and Angs were variable. The expressions of Ties and Angs were correlated with several clinicopathological factors, but did not correlate with the presence of lymph node metastasis. Ties and Angs were highly expressed in human colorectal adenocarcinoma cells.CONCLUSION: These findings suggest that the Tie-Ang receptor-ligand complex is one of the factors involved in the cellular differentiation and progression of human colorectal adenocarcinoma.

Carcinoma of the gastroesophageal junction in Chinese patients

Carcinoma of the gastroesophageal junction(GEJ) is defined as carcinoma that crosses the GEJ line,irrespective of where the tumor epicenter is located.This group of cancer is rare but controversial.Based on study results from the majority of epidemiologic and clinicopathologic investigations carried out in Western countries,this cancer is believed to arise from Barrett's esophagus(BE) and includes both distal esophageal and proximal gastric carcinomas because of similar characteristics in epidemiology,clinicopathology,and molecular pathobiology in relation to BE.As such,the most recent American Joint Committee on Cancer staging manual requires staging all GEJ carcinomas with the rule for esophageal adenocarcinoma(EA).This mandate has been challenged recently by the data from several studies carried out mainly in Chinese patients.The emerging evidence derivedfrom those studies suggests:(1) both BE and EA are uncommon in the Chinese population;(2) almost all GEJ cancers in Chinese arise in the proximal stomach and show the features of proximal gastric cancer,not those of EA;(3) application of the new cancer staging rule to GEJ cancer of Chinese patients cannot stratify patients' prognosis effectively;and(4) prognostic factors of GEJ cancer in Chinese are similar,but not identical,to those of EA.In conclusion,the recent evidence suggests that GEJ cancer in Chinese shows distinct clinicopathologic characteristics that are different from EA.Further investigations in molecular pathology may help illustrate the underlying pathogenesis mechanisms of this cancer in Chinese patients and better manage patients with this fatal disease.

Proposal of a new and simple staging system of colorectal liver metastasis

AIM： To create a new, simple and useful staging system for colorectal liver metastasis analogous to the Tumor Node Metastasis classification system of International Union Against Cancer. METHODS： A retrospective review was undertaken of 81 consecutive patients who underwent partial hepatectomy for colorectal liver metastases （group 1）. Clinical and pathological features of both primary and metastatic liver cancers were entered into a multivariate analysis to determine independent variables helpful in accurately predicting long-term prognosis after hepatectomy. Using selected variables, we created a new staging system like TNM classification. The usefulness of the new staging system was examined in a series of 92 patients from another hospital （group 2）. RESULTS： Multivariate analysis showed that 81 patients in group 1 had significant multiple hepatic tumors with the largest tumor being more than 5 cm in diameter, resectable extrahepatic distant metastases, and independent prognostic factors for poor survival after hepatectomy. Using these three variables, we created a new staging system to classify patients with colorectal liver metastases. Finally, our new staging system classified the patients both in group 1 and in group 2. CONCLUSION： Our new staging system of colorecta liver metastasis is simple and useful for staging patients.

Epidemiology of gastric cancer

The incidence and mortality of gastric cancer have fallen dramatically in US and elsewhere over the past several decades. Nonetheless, gastric cancer remains a major public health issue as the fourth most common cancer and the second leading cause of cancer death worldwide. Demographic trends differ by tumor location and histology. While there has been a marked decline in distal, intestinal type gastric cancers, the incidence of proximal, diffuse type adenocarcinomas of the gastric cardia has been increasing, particularly in the Western countries. Incidence by tumor sub-site also varies widely based on geographic location, race, and socioeconomic status. Distal gastric cancer predominates in developing countries, among blacks, and in lower socioeconomic groups, whereas proximal tumors are more common in developed countries, among whites, and in higher socio-economic classes. Diverging trends in the incidence of gastric cancer by tumor location suggest that they may represent two diseases with different etiologies. The main risk factors for distal gastric cancer include Helicobacter pylori （H pylori） infection and dietary factors, whereas gastroesophageal reflux disease and obesity play important roles in the development of proximal stomach cancer. The purpose of this review is to examine the epidemiology and risk factors of gastric cancer, and to discuss strategies for primary prevention.