International Agency for Research on Cancer

About: International Agency for Research on Cancer is a government organization based out in Lyon, France. It is known for research contribution in the topics: Population & Cancer. The organization has 2989 authors who have published 9010 publications receiving 929752 citations. The organization is also known as: IARC.

Determinants of Clearance of Human Papillomavirus Infections in Colombian Women with Normal Cytology: A Population-based, 5-Year Follow-up Study

Abstract: Little is known about the factors that influence clearance of human papillomavirus (HPV), the primary cause of cervical carcinoma. A total of 227 women cytologically normal and HPV positive at baseline were identified from a population-based cohort of 1,995 Bogota, Colombia, women aged 13-85 years followed between 1993 and 2000 (mean follow-up, 5.3 years). HPV DNA detection and viral load determination were based on a GP5+/GP6+ polymerase chain reaction enzyme immunoassay. Rate ratio estimates for HPV clearance were calculated by using methods for interval-censored survival time data. Analyses were based on 316 type-specific HPV infections. HPV 16 had a significantly lower clearance rate than infections with low-risk types (rate ratio (RR) = 0.47, 95% confidence interval (CI): 0.32, 0.72), HPV types related to HPV 16 (types 31, 33, 35, 52, 58) had intermediate clearance rates (RR = 0.62, 95% CI: 0.47, 0.94), and other high-risk types did not show evidence of slower clearance compared with low-risk types. Infections with single and multiple HPV types had similar clearance rates. There was no evidence of a dose-response relation between clearance and viral load. Observed was slower clearance in parous women (RR = 0.64, 95% CI: 0.47, 0.89) and faster clearance in ever users of oral contraceptives (RR = 1.38, 95% CI: 1.07, 1.77).

Tobacco Use, Occupation, Coffee, Various Nutrients, and Bladder Cancer

Abstract: In a Canadian population-based case-control study of 480 males and 152 female case-control pairs, the relative risk for development of bladder cancer for ever used versus never used cigarettes was 3.9 for males and 2.4 for females, with a dose-response relationship in both sexes. A reduced risk was associated with the use of filter cigarettes compared to nonfilter cigarettes. After control for cigarette usage, a significant risk was noted for male pipe smokers. For male ex-smokers the risk after 15 years of no smoking was less than one-half that of current male smokers. Bladder cancer risk was found for workers in the chemical, rubber, photographic, petroleum, medical, and food processing industries among males and for workers occupationally exposed to dust or fumes among both sexes. Bladder cancer risk was elevated for males consuming all types of coffee, regular coffee, and instant coffee and for females consuming instant coffee, but no dose-response relationship was found. Risk was found for males consuming water from nonpublic supples but not for females. No risk was observed in males or females consuming nitrate-containing foods, beverages other than coffee, or fiddlehead greens. Hair dye usage in females and phenacetin usage in males and females carried no risk. Divergent findings by area for aspirin suggested that an overall association was not causal. Reevaluation of the data on artificial sweeteners confirmed a significant bladder cancer risk in males and a dose-response relationship. The cumulated population attributable risk for bladder cancer was 90% for males from cigarette smoking, industrial exposure, and exposure to nonpublic water supplies and 29% for females from cigarette smoking, industrial exposure, and instant coffee consumption.

Gap Junctional Intercellular Communication and Carcinogenesis

Abstract: It is widely accepted that the process by which a normal cell becomes a malignant tumour is multistage (Doll, 1978; Yamasaki and Weinstein, 1985). It is possible that cell growth is such a tightly controlled process that multiple events are needed in order for a normal cell to deviate so markedly as to be potentially cancerous. Since one of the most important control mechanisms of cell growth and differentiation is intercellular communication, it is reasonable to suppose that aberrant intercellular communication is involved at certain stages of carcinogenesis. Gap junction-mediated intercellular communication is considered to be the sole means by which low molecular weight factors inside a cell can pass directly into the interior of neighbouring cells (Pitts and Finbow, 1986; Loewenstein, 1979). By equalizing the intracellular levels of growth-related factors, gap junctions are considered to play an essential role in the maintenance of homeostasis (Pitts and Finbow, 1986; Loewenstein, 1979).