Journal of Journal of Preventive Medicine Original Article Preventive Medicine & Public Health J Prev Med Public Health 2014;47:281-287 • http://dx.doi.org/10.3961/jpmph.14.018 & Public Health pISSN 1975-8375 eISSN 2233-4521 Differences in the Levels of Gastric Cancer Risk Factors Between Nanjing and Minqing Counties, China Xiang-Quan Xie1,2, Kui-Cheng Zheng1-3, Bing-Shan Wu1, Tie-Hui Chen1, Shan-Rong Lai1, Zai-Sheng Lin1, Kazuo Aoki4 1Fujian Center for Disease Control and Prevention, Fuzhou; 2Fujian Medical University School of Public Health, Fuzhou; 3Fujian Key Laboratory for Zoonoses Research, Fuzhou,China; 4Department of Public Health and Hygiene, Graduate School of Medicine, University of the Ryukyus, Okinawa, Japan Objectives: In Fujian Province, China, gastric cancer is one of the leading causes of mortality among all malignant tumors. Nanjing county and Minqing county are located in inland Fujian and have similar general demographics. However, the adjusted mortality rate of gastric cancer in Minqing was found to be much higher than that in Nanjing. We sought to explore factors associated with this in- creased risk of gastric cancer between the two counties. Methods: We recruited 231 and 224 residents from Nanjing and Minqing, respectively, and analyzed differences between their dietary habits, Helicobacter pylori infection rates, and concentrations of serum pepsinogen I, pepsinogen II, gastrin-17, and ratio of pepsino- gen I:II. Results: Subjects in Minqing had more first-degree relatives who had been diagnosed with upper gastrointestinal tumor, more un- healthy dietary habits, a higher Helicobacter pylori positive rate, and greater proportion of abnormal serum gastrin-17 than those in Nanjing did. Conclusions: The factors that differed between these two counties might indicate that residents in Minqing have a higher risk for de- veloping gastric cancer than those in Nanjing do. Key words: Stomach neoplasms, Food habits, Helicobacter pylori, Pepsinogen, Gastrins INTRODUCTION third leading cause of death among all malignancies [1]. In Fujian Province, located in southeast China, the adjusted mortality rate Gastric cancer is one of the most common malignant tumors of gastric cancer in 2011 was 18.7/100 000 persons (data on the causing death in China. In 2012, the adjusted morbidity rate of incidence rate of gastric cancer is not available). The mortality gastric cancer was 22.7/100 000 persons, only second to lung rate of gastric cancer varies throughout China; for example, the cancer out of all types of malignancies in China. The adjusted first national survey on all-cause mortality showed that the ad- mortality rate of gastric cancer was 17.9/100 000 persons, the justed mortality rate of gastric cancer was 39.4/100 000 persons in coastal areas, but 16.2/100 000 persons in inland areas [2]. Received: May 8, 2014 Accepted: September 4, 2014 Nanjing county and Minqing county are both inland areas in Corresponding author: Kui-Cheng Zheng, MD, PhD No. 76, Jin-Tai Road, Fuzhou 350001, Fujian Province, China Fujian province. According to 2010 data from the Office for Na- Tel: +86-591-87533259, Fax: +86-591-87670235 tional Statistics, the populations were 349 918 and 306 471 and E-mail: [email protected] the mortality rates were 0.642 and 0.634% in Nanjing county This is an Open Access article distributed under the terms of the Creative Commons and Minqing county, respectively. Although these two counties Attribution Non-Commercial License (http://creativecommons.org/licenses/by- have similarly sized populations and similar mortality rates, nc/3.0/) which permits unrestricted non-commercial use, distribution, and repro- duction in any medium, provided the original work is properly cited. the adjusted mortality rate of gastric cancer was 29.7/100 000 PB Copyright © 2014 The Korean Society for Preventive Medicine Copyright © 2014 The Korean Society for Preventive Medicine 281 Xiang-Quan Xie, et al. in Minqing, which was much higher than that in Nanjing Data Collection (19.5/100 000). Unfortunately, the incidence rates of gastric Trained investigators used a questionnaire to obtain self-re- cancer in these two counties were not available. Although mor- ported data on demographic information, family history of tality is substantially influenced by the cancer stage and other gastrointestinal diseases, and dietary habits. clinicopathological features, we think that the incidence rates of gastric cancer in Minqing might be higher than that in Nanjing. Serum Sampling Family history, Helicobacter pylori (H. pylori) infections, con- After an overnight fast from 9 p.m. to 7 a.m., 5 mL of blood suming foods rich in salt or nitro compounds, and unhealthy di- was collected by an experienced medical staff member. After etary habits have been reported as significant risk factors for de- centrifugation, the serum was extracted and stored at -70°C veloping gastric carcinoma [3-5]. Unsurprisingly, previous stud- for further detection. ies have also shown that eating fruits and vegetables, drinking tea, and having good dietary habits are protective factors against Detection of Serum Pepsinogen I, Pepsinogen II, the disease [6,7]. Recently, serological parameters of gastric can- Gastrin-17, and Helicobacter pylori Antibody cer such as serum pepsinogen (PG) I and II, gastrin-17 (G-17), and Serum PG I, PG II, G-17, and H. pylori antibody were measured the H. pylori antibody have been applied to evaluate the risk for with ELISA kits (Biohit Group, Helsinki, Finland). Catalog no. 601 developing gastric cancer and its precancerous lesions known as 010.01CN, 601 020.02CN, 601 035CN, and 601 040.03CN were atrophy gastritis [8-10]. A low PG I or low ratio of PG I to PG II can used to test for PG I, PG II, G-17, and H. pylori antibody, respec- be an indication of gastric corpus atrophy, and a low G-17 level tively. can reflect a gastric antrum atrophy. Moreover, the presence of H. pylori antibodies can indicate infection. Stratification of Variables We aimed to investigate differences in the dietary habits, Subjects were divided into 3 age groups: young (30 to 44 family history, H. pylori infection rate, and distributions of se- years), middle-aged (45 to 59 years), and older (≥60 years). A rum PG I, PG II, ratio of PG I:II, and G-17 level between people food frequency questionnaire was used to collect data on diet. living in Minqing and Nanjing to reveal factors associated with Answers for each food item were collected as never or seldom the higher prevalence of gastric cancer in Minqing than that in (≤1 time/wk), sometimes (2 to 6 time/wk), or regularly (≥7 Nanjing. time/wk). Following the manufacturer’s instructions, a H. pylori antibody level above 30 enzyme immuno units was defined as METHODS H. pylori positive. In addition, a PG I, PG I:II ratio, and G-17 con- centration of <30 μg/L, <3, or <2 pmol/L / >10 pmol/L, re- Subjects spectively, were considered abnormal. A multi-stage sampling method was adopted to recruit sub- jects in Nanjing and Minqing. First, three towns were randomly Statistical Analysis selected from 11 towns in each county. Then, two out of six vil- Epidata 3.1 (EpiData Association, Odense, Fyn, Denmark) lages from each target town were randomly selected, and 30 to was used for dual inputting of questionnaire data to test for 40 families from each target village were selected by the simple parallel consistencies and ensure accuracy. SPSS version 18.0 random selection method. Last, one participant from each family (SPSS Inc., Chicago, IL, USA) was used all statistical analyses. was recruited if they were aged between 30 to 70 years, had been Rank-sum tests were used to analyze quantitative and ranked living in that county for at least five years, were without any clini- data. chi-squared tests were used to analyze categorical data. cally diagnosed gastric diseases, and had never taken a proton For all tests, a p<0.05 was considered statistically significant. pump inhibitor. If this recruited participant refused participation, another person living in that village and meeting these require- RESULTS ments were recruited; the replacement rate was less than 10%. Every subject provided informed consent before participation. Demographic Information In total, 231 subjects were recruited from Nanjing, including 136 males (58.9%) and 95 females (41.1%), and the average 282 Analysis on Diet Habits, HP, PG, and G-17 Table 1. Number of subjects with a family history of gastroin- age among all subjects was 49.5±9.9 years old. In Minqing, testinal cancers between Nanjing and Minqing counties 224 subjects were recruited, including 117 males (52.2%) and Total Nanjing Minqing p-value 107 females (47.8%), and the average age was 50.2±10.0 years No. of subjects 455 231 224 - old for the total population. No significant differences were Upper gastrointestinal 17 (3.7) 3 (1.3) 14 (6.3) 0.0051 found for the ratio between genders or average ages between tumors Nanjing and Minqing. Gastric ulcer 12 (2.6) 8 (3.5) 4 (1.8) 0.231 Duodenal ulcer 3 (0.7) 2 (0.9) 1 (0.4) 1.001 Chronic gastritis 18 (4.0) 10 (4.3) 8 (3.6) 0.681 Family History Other gastrointestinal As shown in Table 1, the analysis of family history data indi- 1 (0.2) 1 (0.4) 0 (0.0) 1.001 disease cated that the percentage of the subjects with a first-degree rel- Values are presented as number (%). ative (parents, grandparents, brothers, or sisters) who had been 1Pearon chi-squared test (Nanjing vs. Minqing). Table 2. Distribution and comparison of dietary habits between Nanjing and Minqing