An analysis of esophageal cancer incidence in Cixian county from 1974 to 1996

AIM: To describe the incidence of esophageal cancer (EC)in Cixian, a county of Hebei province during 1974-1996. Weanalyzed the sex and age characteristics as well as thegeographic distribution of EC, in order to determine theimpact so that methods of preventing and controlling EC inCixian can be put in place.METHODS: Since the early 1970s, the cancer registrysystem has been established, which collects the cancerincidence in Cixian county. The malignant tumors were codedaccording to International Classification of Disease IX (ICD-9). All the data were checked and analyzed using EPIINFO.RESULTS: The trend of the incidence rate of EC from 1974to 1996 had declined, (229.9/100 000 vs 178.5/100 000, Oddsratio= 1.47, 95 % CI: 1.32～1.63, X2=52.89. trend X2=26.54,P＜0.001). The incidence rate of males declined significantly(281.81/100 000 vs 157.96/100 000, Odds ratio=1.61, 95 %CI: 1.41～1.84, X2=47.85. Trend X2=44.86, P＜0.001),whereas, the females remained steady (157.96/100 000 vs133.41/100 000, odds ratio=1.28, 95 % CI:1.17～1.49,X2=9.26. trend X2=2.69, P＞0.05). Male average annualincidence rate was 142.80/100 000 and the female's was95.18/100 000. The sex ratio (males to females) was 1.50:1.The incidence rate was increasing along with the age. As tothe geographic distribution, the incidence rate in mountainousareas and hilly areas showed a significantly declining trend(mountainous areas, trend X2=149.93, P＜0.001; hilly areas,trend X2=42.70, P＜0.001). The incidence rate of EC in plainareas had increased (trend X2=22.39, P＜0.001).CONCLUSION: The incidence rate of EC in Cixian countyshows a trend and has declined after two decades, especiallyin mountainous area. But compared to other regions in theworld, Cixian county still had a high incidence rate of EC.

Single nucleotide polymorphism in DNA methyltransferase 3B promoter and its association with gastric cardiac adenocarcinoma in North China

AIM:To investigate the association between single nucleotide polymorphism (SNP) in promoter of the DNA methyltrans-ferase 3B(DNMT3B) gene and risk for development and lymphatic metastasis of gastric cardiac adenocarcinoma (GCA). METHODS: The hospital based case-control study included 212 GCA patients and 294 control subjects without overt cancer. The DNMT3B SNP was genotyped by PCR and restriction fragment length polymorphism (RFLP) analysis. RESULTS: The C/C genotype was not detected in both GCA patients and controls. In control subjects, the frequency of T/T and C/T genotypes was 94.9% and 5.1% respectively, and that of T and C alleles was 97.4% and 2.6%, respectively. The genotype and allelotype distribution in the GCA patients was not significantly different from that in controls (P=0.34 and 0.33, respectively). When stratified by smoking status and family history of upper gastrointestinal cancer, significant difference in the genotype distribution was not observed between GCA patients and controls. The distribution of DNMT3B genotypes in GCA patents with or without lymphatic metastasis did not show significant difference (P= 0.42). CONCLUSION: The distribution of DNMT3B SNP in North China is distinct from that in Caucasians. Although this SNP has been associated with susceptibility to lung, head, neck and breast cancer, it may not be used as a stratification marker to predict susceptibility and lymphatic metastasis of GCA, at least in the population of North China.

Research and control of well water pollution in high esophageal cancer areas

AIM: In order to detect risk factors for esophageal cancer,a national research program was carried out during the Eighth Five-Year Plan (from 1991 to 1995). METHODS: Cixian County and Chichen County in Hebei Province were selected as the index and the control for the study fields with higher or lower incidence of esophagus cancer in China, respectively. In these areas, we investigated the pollution of three nitrogenous compounds in well water for drinking and the use of nitrogen fertilizer in farming. RESULTS: In well water, nitrate nitrogen, nitrite nitrogen and ammonia nitrogen were 8.77 mg/L, 0.014 mg/L and 0.009 mg/L in Cixian County in 1993, respectively. They were significantly higher than their levels (3.84 mg/L, 0.004 mg/L and 0.004 mg/L) in Chichen County (P＜0.01, t=6.281,t=3.784,t=3.775). There was a trend that the nitrogenous compounds in well water increased from 1993 to 1996.The amount of nitrogen fertilizer used in farming was 787.6 kg per hectare land in Cixian County in 1991, significantly higher than 186 kg per hectare in Chichen County (t=9.603,P＜0.001). CONCLUSION: These investigations indicate that the poilution of nitrogenous compounds in well water for drinking is closely related to the use of nitrogen fertlizer in farming, and there is a significantly positive correlation between the level of three nitrogenous compounds in well water and the mortality ofesophageal cancer (correlation coefficient =0.5992). We suggest that improvement of well system for drinking water quality should be an effective measure for esophageal cancer prevention and control in rural areas.

No association of the matrix metalloproteinase 1 promoter polymorphism with susceptibility to esophageal squamous cell carcinoma and gastric cardiac adenocarcinoma in northern China

AIM: To investigate association of the 2Gor1Gsingle nudeotide polymorphism (SNP) in matrix metalloproteinase 1 (MMP1) promoter with susceptibility to esophageal squam-ous cell carcinoma (ESCC) and gastric cardiac adenocarcinoma (GCA) in a population of North China. METHODS: MMP1 promoter SNP was genotyped by polymerase-chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis in 417 cancer patients (234 ESCC and 183 GCA) and 350 healthy controls. RESULTS: The genotype frequencies of the MMP1 promoter SNP in healthy controls were 55.4% (2G/2G), 30% (1G/2G) and 14.6% (1G/1G), respectively. The genotype and allelotype distribution in ESCC and GCA patients was not significantly different from that in healthy controls (all lvalues were above 0.05). Compared with the 1G/1Ggenotype, neither the 2G/2Gnor in combination with the 1G/2G genotype significantly modified the risk of developing ESCC and GCA, the adjusted odds ratio was 1.28 (95%CI = 0.78-2.09), 1.23 (95%CI = 0.38-2.05) in ESCC and 1.39 (95%CI = 0.80-2.41), 1.34 (95%CI = 0.74-2.40) in GCA, respectively. When stratified by smoking status and family history of upper gastrointestinal cancer, the 2G/2Ggenotype alone or in combination with the 1G/2G genotype also did not show any significant influence on the risk of ESCC and GCA development. In addition, influence of the MMP1 SNP on lymphatic metastasis in ESCC and GCA was also not obs-erved. CONCLUSION: The 2Gor 1GSNP in the MMP1 promoter might not modify the risk of ESCC and GCA development and might not be used as a stratification marker to predict the potential of lymphatic metastasis in these two tumor types.

Endoscopic survey of esophageal cancer in a high-risk area of China

AIM: To characterize the histological types of esophageal and cardiac mucosa by endoscopic survey of a population in a high-risk area of esophageal cancer of China. METHODS: A selected cohort of residents in Cixian County during December 2001 and May 2002 was surveyed by using Lugol's staining, followed by computer-based statistical analysis of the data with SPSS 10.0 software. RESULTS: Histologically, the detection rates of squamous epithelial acanthosis, squamous epithelial atrophy, and basal cell hyperplasia in the esophagus were 1.9% (38/2013),0.1% (3/2013) and 0.9% (18/2013) respectively, and those of mild, moderate, and severe esophagitis were 34.9% (703/2013), 1.6% (33/2013) and 0.2% (2/2013) respectively. Mild, moderate, and severe esophageal dysplasia were detected in 8.6% (172/2013), 7.8% (157/2013) and 2.6% (53/2013) respectively in the selected population, whereas in situ carcinoma, intramucosal carcinoma, invasive squamous carcinoma of the esophagus in 2.5% (50/2013),0.2% (4/2013) and 0.7% (14/2013) respectively. The detection rates of non-atrophic gastritis and atrophic gastritis of the cardia were 36.3% (730/2013) and 11.5% (232/2013) respectively, with mild and severe dysplasia of the cardia detected in 2.5% (51/2013) and 0.8% (17/2013), respectively, in this population; the rates of intramucosal adenocarcinoma and invasive adenocarcinoma of the cardia were 0.1% (3/2013) and 0.8% (17/2013) respectively. The detection rate of esophageal cancer at early stage was 79.4% (54/68). The survey rate (ratio of examined population to expected population) was 73.8% (2013/2725). CONCLUSION: Histologic types of the esophageal and cardiac mucosa were characterized by endoscopic survey in a high-risk population of esophageal cancer, which may help the early detection and treatment of esophageal and cardiac cancers and dysplasia, and reduce the mortality of such malignancies.

Epoxide hydrolase Tyr113 His polymorphism is not associated with susceptibility to esophageal squamous cell carcinoma in population of North China

AIM: To investigate the possible association of microsomal epoxide hydrolase ( mEH) Tyr113 His polymorphism with susceptibility to esophageal squamous cell carcinoma (ESCC) in a population of North China.METHODS: The mEH-Tyr113 His genotypes were determined by polymerase-chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis in 257 patients with esophageal squamous cell carcinoma (ESCC) and 252 healthy subjects as a control group.RESULTS: The frequencies for Tyr and His alleles were 44.2 %, 55.8 % in ESCC patients, and 44.0 % and 56.0 %in healthy subjects, respectively. No statistic difference in allele distribution was observed between ESCC patients and controls (x2=0.008, P=0.929). The overall genotype distribution difference was not observed between cancer cases and controls (x2=2.116, P=-0.347). Compared with Tyr/Tyr genotype, neither His/His genotype nor in combination with Tyr/His genotype significantly modified the risk of the development of ESCC, the adjusted odds ratio was 1.076 (95 % CI=0.850-1.361) and 0.756 (95 % CI=0.493-1.157),respectively. When stratified for sex, age, smoking status and family history of upper gastrointestinal cancer, His/His genotype alone or in combination with Tyr/His genotype also did not show any significant influence on the risk of developing ESCC.CONCLUSION: MEH Tyr113His polymorphism may not be used as a stratification marker in screening individuals at a high risk of ESCC.

Age scope of high-risk population for esophageal cancer in Ci county

AIM: To define the age scope of high-risk population for esophageal cancer (EC) in Ci county. METHODS: The results of endoscopic examination of 2 013 subjects, cytological screening of 16 763 persons and records of 9 265 patients with EC were analyzed by Ridit methods, the standard age group was 45-49 year group. RESULTS: The average age of patients with moderate esophageal epithelium dysplasia by endoscopic examination was 53.5 years, of severe esophageal epithelium dysplasia, 51.4 years, early EC, 55.6 years. The average age of stage one severe epithelium dysplasia (SEEDⅠ) by cytological screening was 51.2 years, of stage two severe epithelium esophageal dysplasia (SEED Ⅱ) 51.6 years, of advanced EC 61.7 years. In the group of 40-year olds, the value of Ridit by pathological diagnosis was 0.46, 95% CI, 0.45-0.47, that by cytological diagnosis was 0.45, 95% CI, 0.43-0.47. As the age increased at five-year intervals, the value of Ridit increased significantly. CONCLUSION: In Ci county of a high incidence area of EC, the age definition of high-risk population should be above 45 years.