No abstract

Objective. To estimate the prevalence, incidence, survival, and disease characteristics of systemic sclerosis (SSc) in the Detroit tricounty area.Methods. A census of SSc cases for the period 1989-1991 was conducted in the Detroit area, using multiple sources for case identification. Diagnoses were verified by medical record review. Capture-recapture analysis was used to estimate the total SSc population. Cases of localized scleroderma (morphea and linear disease) were excluded.Results. Based on 706 verified cases of SSc, prevalence was initially estimated to be 242.0 cases per million adults (95% confidence interval [95% CI] 213-274), with an annual incidence of 19.3 new cases per million adults per year (95% CI 12.4-30.2). Capturerecapture analysis, based on the degree of overlap of verified cases among multiple sources, resulted in a revised prevalence estimate of 276 cases per million adults (95% CI 245-310). Sex-and race-specific prevalence estimates were significantly higher for women than for men, and for blacks than for whites. The average age at diagnosis was significantly younger for blacks than for whites. Compared with white patients, black patients were almost twice as likely to have diffuse disease (prevalence proportion ratio 1.86, 95% CI 1.48-2.35). Median survival was ϳ11 years. Factors negatively affecting survival included male sex (hazard ratio 1.81, 95% CI 1.29-2.55) and older age at diagnosis (hazard ratio 1.04, 95% CI 1.03-1.05).Conclusion. This study establishes baseline estimates of SSc occurrence and characteristics in a large US cohort consisting primarily of black adults and white adults. These data should facilitate research regarding the role of geographic, ethnic, racial, and environmental factors for this disease in comparison populations.

A causal link between chronic inflammation and carcinogenesis is explored by reviewing illustrative examples of specific cancers and causal agents and mechanisms. The causal agents or pathologic conditions include microbial agents, gastroesophageal reflux, chronic cholecystitis and cholelithiasis, inflammatory bowel disease, and specific agents that cause chronic obstructive or diffuse interstitial lung disease. The proportion of total cancer deaths attributable to infectious agents is estimated to be about 20% to 25% in developing countries and 7% to 10% in more industrialized countries. Recurrent or persistent inflammation may induce, promote, or influence susceptibility to carcinogenesis by causing DNA damage, inciting tissue reparative proliferation, and/or creating a stromal "soil" that is enriched with cytokines and growth factors. Future research on the complex cascade of cellular and humoral factors participating in the chronic inflammatory process will further understanding of the pathogenesis of various cancers and potentially provide a rationale for targeted chemopreventive interventions.

Previous epidemiologic studies evaluating risk factors for lower urinary tract symptoms (LUTS) have focused on White populations. Between September 1996 and January 1998, in a population-based sample of African-American men aged 40-79 years in Flint, Michigan, the authors assessed the role of putative sociodemographic, lifestyle, and medical history risk factors in moderate to severe LUTS, including the subcategories of obstructive and irritative symptoms. After the exclusion of men with prostate cancer or prior prostate surgery and men who were taking alpha-blockers for urinary tract symptoms, 708 participants provided responses to a structured interviewer-administered questionnaire. After multivariable adjustment, current and former smokers were at increased risk of moderate to severe LUTS, including obstructive symptoms. Heavy alcohol consumption and a history of hypertension or diabetes were positively associated with LUTS, and high income (>/=$30,000) was inversely associated with LUTS and with obstructive and irritative symptoms. A history of heart disease was positively associated with LUTS and with irritative symptoms. To the authors' knowledge, this was the first population-based study undertaken in African-American men to evaluate putative risk factors for moderate to severe LUTS, including subcategories of obstructive and irritative urinary symptoms. These results describe associations with specific lifestyle and medical history risk factors.

PURPOSE: The mucosa of the small intestine encompasses about 90% of the luminal surface area of the digestive system, but only 2% of the total annual gastrointestinal cancer incidence in the United States. METHODS: The remarkable contrast in age-standardized cancer incidence between the small and large intestine has been reviewed with respect to the cell type patterns, demographic features, and molecular characteristics of neoplasms. RESULTS: Particularly noteworthy is the predominance of adenocarcinoma in the colon, which exceeds 98% of the total incidence by cell type, in contrast to that of 30% to 40% in the small intestine, resulting in an age-standardized ratio of rates exceeding 50-fold. The prevalence of adenomas and carcinomas is most prominent in the duodenum and proximal jejunum. The positive correlation in global incidence rates of small and large intestinal neoplasms and the reciprocal increases in risk of second primary adenocarcinomas suggest that there are common environmental risk factors. The pathophysiology of Crohn inflammatory bowel disease and the elevated risk of adenocarcinoma demonstrate the significance of the impaired integrity of the mucosal barrier and of aberrant immune responses to luminal indigenous and potentially pathogenic microorganisms. CONCLUSION: In advancing a putative mechanism for the contrasting mucosal susceptibilities of the small and large intestine, substantial differences are underscored in the diverse taxonomy, concentration and metabolic activity of anaerobic organisms, rate of intestinal transit, changing pH, and the enterohepatic recycling and metabolism of bile acids. Experimental and epidemiologic studies are cited that suggest that the changing microecology, particularly in the colon, is associated with enhanced metabolic activation of ingested and endogenously formed procarcinogenic substrates.