Steven D. Mark

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Esophageal cancer incidence and mortality rates in Linxian, China are among the highest in the world. We examined risk factors for esophageal squamous cell carcinoma (ESCC), gastric cardia cancer (GCC), and gastric noncardia cancer (GNCC) in a population-based, prospective study of 29,584 adults who participated in the Linxian General Population Trial. All(More)
Objective: To determine if genetic polymorphisms of CYP1A1, GSTM1, GSTP1, or GSTT1 are associated with an increased risk of developing esophageal squamous cell carcinoma (ESCC), gastric cardia cancer (GCC), or either in a high-risk Asian population. Methods: We conducted a case-cohort analysis with 5 years of prospective follow-up. The analytical cohort(More)
The population of Linxian in north central China is at high risk for gastric cardia adenocarcinoma (GCC) and esophageal squamous cell carcinoma (ESCC), and chronic inflammation may contribute to this risk. Interleukin-8 (IL8), a potent chemoattractant, has three well-characterized single nucleotide polymorphisms (SNP), one (-251) of which alters(More)
BACKGROUND Tooth loss has previously been associated with a higher risk of cancer, heart disease, and stroke, but the role of confounding by smoking remains an issue. METHODS We conducted a cohort study including 29,584 healthy, rural Chinese adults who were participants in a chemoprevention trial from 1986 through 1991 and who have been followed-up(More)
Objective: To determine the association between tooth loss and the risk of developing esophageal squamous cell carcinoma, gastric cardia adenocarcinoma, or gastric non-cardia adenocarcinoma in a prospective study. Methods: Cox proportional hazards regression was used to examine these associations in a 28,868-person cohort followed prospectively for 5.25(More)
BACKGROUND 1,1,1-Trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) exposure has been demonstrated to cause liver tumors in laboratory rodents. DDT's persistent metabolite and environmental degradation product, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), has also been associated with liver tumors in laboratory animals. Whether DDT and DDE are associated(More)
Linxian, a rural county in North Central China, has among the highest rates of esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinoma (GCA) in the world. Its inhabitants have documented chronic nutritional inadequacies, including folate and vitamin B(12) deficiencies. Using a cohort we have been studying in Linxian since 1985, we(More)
Estimating the causal effect of quitting smoking on time to death or first myocardial infarction requires that one control for the differences in risk factors between individuals who elect to quite at each time t versus those who elect to continue smoking at time t. In this paper we examine the limitations of standard time varying Cox proportional hazards(More)
Each year, esophageal and gastric cancers cause more than 900,000 deaths worldwide. Human papilloma virus (HPV), especially type 16, has been suggested to have a role in the etiology of esophageal cancer, however, the results of previous seroepidemiological studies have not been consistent. We conducted a large prospective study to examine the association(More)