High fruit intake and high urinary isoprostane excretion were each independent predictors of gastric cancer (Table 3), but predictability was lost when both entities were included in the same analysis, which suggested that these are codependent variables. 8-iso PGF2 excretion was higher in cases (0.014; IQR: 0.008C0.021) than in controls (0.011; IQR: 0.006C0.018; = 0.039). On univariate analysis, habitual fruit intake was lower in cases than in controls during the dry season (= 0.02). On multivariate analysis, smoking (OR: 7.22; IQR: 1.38C37.9) and gastric atrophy (OR: 2.43; IQR: 1.12C5.13) were independently associated with cancer, and higher fruit intake was protective (OR: 0.44; IQR: 0.20C0.95). Isoprostane excretion was inversely correlated with total fruit intake ( = ?0.23; = 140; = 0.006). Conclusion: Urinary 8-iso PGF2 excretion was associated with the risk of gastric cancer, as were smoking and gastric atrophy, but increased fruit intake conferred protection. This trial was registered at www.pactr.org as ISRCTN52971746. INTRODUCTION Gastric cancer is the fourth most common type of cancer and the second most frequent cause of cancer death worldwide (1C3). The WHO predicts an increase in cancer rates by 50% over the next 20 y (1). Hypothesized risk factors for increasing rates include inflammatory, infectious, and environmental factors (3C6). Environmental factors particularly related to diet have been implicated in gastric carcinogenesis through a direct (nitrosamines in smoked foods) or indirect mechanism (altering cellular dynamics of gastric mucosa) (7). Nitrosamine ingestion in smoked and pickled foods has been proposed as an explanation for the high incidence of gastric cancer in Japan. In Zambia, the Vandetanib HCl epidemiology of gastric cancer is largely unexplored, but a recent audit of endoscopy and pathology records suggested that the incidence has shifted to younger adults (8). Furthermore, the contribution of status. The Zambian diet predominantly consists of a high intake of maize starch as a hot paste (Laboratory assays). Laboratory assays Urinary isoprostane and creatinine concentrations were measured by using Isoprostane and Creatinine Microplate Assays (Oxford Biomedical) according to the manufacturer’s instructions. A subset (28%) of duplicates of the urine aliquots was transported to St Louis for gas chromatographyCmass spectrometry quantitation of total (free + esterified) urinary 8-iso prostaglandin-F2 (8-iso-PGF2). Briefly, 4 ng deuterated internal standard [8-iso PGF2-d4 (8-iso PGF2-3,3,4,4-d4) Cayman Chemical Co] (17) was added to each urine sample (400 L). After alkaline hydrolysis, urine 8-isoprostanes were isolated by using an immunoaffinity resin (Cayman Chemical Co), which was chemically derivatized to form their pentafluorobenzyl ester-trimethylsilyl ether, and analyzed by gas chromatographyCnegative chemical ionization mass spectrometry by using selective ion monitoring at 569 and 573. The 569/573 signal intensity area Vandetanib HCl ratios were calculated, compared with the same signals generated with a concentration standard curve, and used to quantify the amount of total 8-iso PGF2 in urine. Vandetanib HCl serology, pepsinogen 1 and 2, and gastrin-17 assays were performed by using Biohit Gastro Panel ELISA kits (Biohit); for CagA, ELISA kits were obtained from Genesis Diagnostics and used according to the manufacturer’s instructions. The presence of HIV infection was determined by the virology laboratory of the UTH by using Determine (Alere) for screening and Unigold test strips (Trinity Biotech) for confirmation. Statistical analysis Isoprostane and food-frequency data did not follow a Gaussian distribution, so continuous variables are presented as medians and IQRs. Food-frequency data were analyzed per patient, and the total daily intake of portions of each food were computed for each case or control. Only total consumption in each group was analyzed (except for the other food category in which items were analyzed individually) to minimize the number of statistical tests required. Seasonality was analyzed by dividing the month of recruitment into 3 seasons: cold (MayCAugust), hot (SeptemberCNovember), and Vandetanib HCl rainy (DecemberCApril). A pepsinogen 1:2 ratio was regarded as low (indicative of atrophy of the body/fundus) if 3.0, and gastrin-17 was classified as low if 1.0 pmol/L. All analyses were performed by using Stata 10.1 (Stata Corp). Associations between risk factors and cancer are presented as ORs with 95% CIs, and were determined by using Fisher’s exact test. To compare continuous variables in cases and controls, the Kruskal-Wallis test was used. For multivariate analysis, ELTD1 continuous variables were dichotomized around the median, and a backward stepwise strategy was used to derive a final unconditional logistic regression model. In all instances, a value 0.05 was required for statistical significance. RESULTS Between November 2010 and January 2012, a total of 315 patients gave consent for inclusion in the study. Of the 105 patients whose endoscopy showed.