Gastric cancer incidence estimation in a resource-limited nation: use of endoscopy registry methodology.

PURPOSE: Cancer epidemiology is challenging in developing nations, in the absence of reliable pathology-based cancer registries. Clinical experience suggests that the incidence of gastric cancer is high in Honduras, in contrast to the limited available national statistics at the time of study initiation (IARC GLOBOCAN 2002: males 15.2, females 10.8). We estimate the incidence of gastric cancer for Honduras using an endoscopy registry as a complimentary resource. METHODS: We conducted a retrospective analysis of incident noncardia gastric adenocarcinoma cases in western Honduras for the period 2000-2009. This region is well circumscribed geopolitically with a single district hospital and established referral patterns, to provide a unique epidemiological niche to facilitate estimation of incidence rates. A prospective, comprehensive database of all endoscopy procedures from this hospital was utilized at the primary data source. The catchment area for gastroenterology services for the at-risk population was validated by calculating the overall endoscopy utilization rates for each municipality in western Honduras. Incident cases of gastric adenocarcinoma were determined by the endoscopic diagnosis. Pathology services are not financed by the Ministry of Health, and histology data were incorporated when available. Population statistics were obtained from the Honduras National Statistics Institute (INE). Age-standardized incidence rates (ASIRs) were calculated using world standard population fractions. RESULTS: The catchment area for western Honduras was validated with the municipality threshold of 30 endoscopies per 10(6) person-years, with inclusion of a total of 40 municipalities. In the western Honduras catchment area, there were 670 incident cases (439 M, 231 F) of noncardia gastric adenocarcinoma during the study decade 2000-2009. Notably, 67 (10.0 %) and 165 (24.6 %) of cases were under the ages of 45 and 55, respectively. The case-finding rate was 5.1 endoscopies performed for each new diagnosis of gastric cancer. The ASIRs for the decade were 30.8 for males and 13.9 for females. Clinically, 60.3 % of gastric cancers were Borrmann type 3 (ulcerated mass), and evidence of advanced disease with pyloric obstruction was common (35.2 %). Subtypes by the Lauren classification were distributed among diffuse (56 %), intestinal (34 %), and indeterminate (9.9 %), in subjects with available pathology (526/670). CONCLUSIONS: The endoscopy procedure registry may serve as a complimentary data resource for gastric cancer incidence estimation in resource-limited nation settings wherein pathology services and cancer registries are absent. The results remain an underestimation in this setting due to the challenges of access to care and related factors. The methodology helps to more fully characterize the high incidence of gastric cancer in western Honduras and this region of Central America and demonstrate the need for additional epidemiology research, and interventions focused on prevention and treatment.

Single and multiple dose pharmacokinetics of maraviroc in saliva, semen, and rectal tissue of healthy HIV-negative men.

BACKGROUND: Antiretroviral pharmacology in seminal plasma (SP) and rectal tissue (RT) may provide insight into antiretroviral resistance and the prevention of sexual transmission of human immunodeficiency virus (HIV). Saliva may be of utility for noninvasively measuring adherence. METHODS: A pharmacokinetic study was performed in 12 HIV-negative men receiving maraviroc 300 mg twice daily for 8 days. Seven time-matched pairs of blood plasma (BP) and saliva samples were collected over 12 h on day 1 (PK1) and days 7 and 8 (PK2). One RT sample from each subject was collected during PK1 and PK2. Two SP samples were collected from each subject during PK1, and 6 SP samples were collected from each subject during PK2. RESULTS: SP AUCs were ∼50% lower than BP. However, protein binding in SP ranged from 4% to 25%, resulting in protein-free concentrations >2-fold higher than BP. RT AUCs were 7.5- to 26-fold higher than BP. Maraviroc saliva AUCs were ∼70% lower than BP, but saliva concentrations correlated with BP (r(2) = 0.58). CONCLUSIONS: More pharmacologically available maraviroc was found in SP than BP. High RT concentrations are promising for preventing rectal HIV acquisition. Saliva correlation with BP suggests that this may be useful for monitoring adherence. CLINICAL TRIALS REGISTRATION: NCT00775294.

Gastric cancer and the high combination prevalence of host cytokine genotypes and Helicobacter pylori in Honduras.

BACKGROUND & AIMS: Inflammatory cytokine polymorphisms are associated with gastric adenocarcinoma in Helicobacter pylori-infected patients in Europe and Asia. We investigated the cytokine profile in the Latino population, specifically Honduras, a high-incidence region, and the use of the combination prevalence of H pylori and genotypes in identifying high-risk populations. METHODS: A population-based case-control study identified 170 incident gastric cancer cases and 162 healthy village controls. Interleukin (IL)-Ibeta-511, IL-1RN, IL-10-1082, and tumor necrosis factor-alpha-308 genotypes were determined. We define the combination prevalence index (CPI) as the product of H pylori and IL-1beta-511T+ genotype prevalence in healthy subjects. Medline identified gastric cancer studies to facilitate country-specific CPI calculations. RESULTS: In healthy, population-based Honduran controls, IL-1beta-511T+ prevalence was 81% (95% confidence interval, 75%-87%; CT, 57%; TT, 25%), which was among the highest reported. IL-10-1082A+ prevalence was 93% (95% confidence interval, 88%-97%), mirroring Asian populations. Seventeen percent were homozygous for both proinflammatory cytokines (TT/AA), with increased risk among cases (odds ratio, 2.6; 95% confidence intervals, 1.0-6.8). Tumor necrosis factor-alpha polymorphisms were nearly absent. Endemic H pylori infection (85%) was confirmed. Importantly, the CPI association with country incidence is highly significant (P = .0057), based on 16 global populations and Honduras. Sensitivity analysis confirms a robust CPI. CONCLUSIONS: The CPI, based on IL-1beta genotypes, has a strong association with country-specific gastric cancer incidence. The CPI correlation supports the chronic inflammation carcinogenesis model, and may explain the geographic variation. We report a novel cytokine profile in Honduras that mirrors Asian populations and explains the high incidence rates. This may have dyspepsia management and screening implications for the growing US Latino population.