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.

Functions of poly(ADP-ribose) polymerase in controlling telomere length and chromosomal stability.

Abstract: In most eukaryotes, poly(ADP-ribose) polymerase (PARP) recognizes DNA strand interruptions generated in vivo. DNA binding by PARP triggers primarily its own modification by the sequential addition of ADP-ribose units to form polymers; this modification, in turn, causes the release of PARP from DNA ends. Studies on the effects of the disruption of the gene encoding PARP (Adprt1, formerly Adprp) in mice have demonstrated roles for PARP in recovery from DNA damage and in suppressing recombination processes involving DNA ends. Telomeres are the natural termini of chromosomes and are, therefore, potential targets of PARP. Here, by the use of two different techniques, we show that mice lacking PARP display telomere shortening compared with wild-type mice. Telomere shortening is seen in different genetic backgrounds and in different tissues, both from embryos and adult mice. In vitro telomerase activity, however, is not altered in Adprt1-/- mouse fibroblasts. Furthermore, cytogenetic analysis of mouse embryonic fibroblasts reveals that lack of PARP is associated with severe chromosomal instability, characterized by increased frequencies of chromosome fusions and aneuploidy. The absence of PARP does not affect the presence of single-strand overhangs, naturally present at the ends of telomeres. This study therefore reveals an unanticipated role for PARP in telomere length regulation and provides insights into its functions in maintaining genomic integrity.

Pooled analysis of the accuracy of five cervical cancer screening tests assessed in eleven studies in Africa and India.

Abstract: Cervical cancer is the main cancer among women in sub-Saharan Africa, India and other parts of the developing world. Evaluation of screening performance of effective, feasible and affordable early detection and management methods is a public health priority. Five screening methods, naked eye visual inspection of the cervix uteri after application of diluted acetic acid (VIA), or Lugol's iodine (VILI) or with a magnifying device (VIAM), the Pap smear and human papillomavirus testing with the high-risk probe of the Hybrid Capture-2 assay (HC2), were evaluated in 11 studies in India and Africa. More than 58,000 women, aged 25-64 years, were tested with 2-5 screening tests and outcome verification was done on all women independent of the screen test results. The outcome was presence or absence of cervical intraepithelial neoplasia (CIN) of different degrees or invasive cervical cancer. Verification was based on colposcopy and histological interpretation of colposcopy-directed biopsies. Negative colposcopy was accepted as a truly negative outcome. VIA showed a sensitivity of 79% (95% CI 73-85%) and 83% (95% CI 77-89%), and a specificity of 85% (95% CI 81-89%) and 84% (95% CI 80-88%) for the outcomes CIN2+ or CIN3+, respectively. VILI was on average 10% more sensitive and equally specific. VIAM showed similar results as VIA. The Pap smear showed lowest sensitivity, even at the lowest cutoff of atypical squamous cells of undetermined significance (57%; 95% CI 38-76%) for CIN2+ but the specificity was rather high (93%; 95% CI 89-97%). The HC2-assay showed a sensitivity for CIN2+ of 62% (95% CI 56-68%) and a specificity of 94% (95% CI 92-95%). Substantial interstudy variation was observed in the accuracy of the visual screening methods. Accuracy of visual methods and cytology increased over time, whereas performance of HC2 was constant. Results of visual tests and colposcopy were highly correlated. This study was the largest ever done that evaluates the cross-sectional accuracy of screening tests for cervical cancer precursors in developing countries. The merit of the study was that all screened subjects were submitted to confirmatory investigations avoiding to verification bias. A major finding was the consistently higher sensitivity but equal specificity of VILI compared with VIA. Nevertheless, some caution is warranted in the interpretation of observed accuracy measures, since a certain degree of gold standard misclassification cannot be excluded. Because of the correlation between visual screening tests and colposcopy and a certain degree of over-diagnosis of apparent CIN2+ by study pathologists, it is possible that both sensitivity and specificity of VIA and VILI were overestimated. Gold standard verification error could also explain the surprisingly low sensitivity of HC2, which contrasts with findings from other studies.

Tea drinking habits and oesophageal cancer in a high risk area in northern Iran: population based case-control study

Abstract: Objective To investigate the association between tea drinking habits in Golestan province, northern Iran, and risk of oesophageal squamous cell carcinoma. Design Population based case-control study. In addition, patterns of tea drinking and temperature at which tea was drunk were measured among healthy participants in a cohort study. Setting Golestan province, northern Iran, an area with a high incidence of oesophageal squamous cell carcinoma. Participants 300 histologically proved cases of oesophageal squamous cell carcinoma and 571 matched neighbourhood controls in the case-control study and 48 582 participants in the cohort study. Main outcome measure Odds ratio of oesophageal squamous cell carcinoma associated with drinking hot tea. Results Nearly all (98%) of the cohort participants drank black tea regularly, with a mean volume consumed of over one litre a day. 39.0% of participants drank their tea at temperatures less than 60°C, 38.9% at 60-64°C, and 22.0% at 65°C or higher. A moderate agreement was found between reported tea drinking temperature and actual temperature measurements (weighted κ 0.49). The results of the case-control study showed that compared with drinking lukewarm or warm tea, drinking hot tea (odds ratio 2.07, 95% confidence interval 1.28 to 3.35) or very hot tea (8.16, 3.93 to 16.9) was associated with an increased risk of oesophageal cancer. Likewise, compared with drinking tea four or more minutes after being poured, drinking tea 2-3 minutes after pouring (2.49, 1.62 to 3.83) or less than two minutes after pouring (5.41, 2.63 to 11.1) was associated with a significantly increased risk. A strong agreement was found between responses to the questions on temperature at which tea was drunk and interval from tea being poured to being drunk (weighted κ 0.68). Conclusion Drinking hot tea, a habit common in Golestan province, was strongly associated with a higher risk of oesophageal cancer. Reza Malekzadeh and other authors of this population based case-control study talk about the effect of tea drinking and oesophageal cancer in Golestan province, northern Iran

Nutritional factors in colorectal cancer risk: a case-control study in Majorca

Abstract: The relationship between energy intake, selected nutrients and colorectal cancer was investigated in the population of Majorca, a Spanish island in the Mediterranean basin. A population-based case-control study using food frequency questionnaires was conducted during the period 1984-1988 and included 286 cases of colorectal cancer, 295 population controls and 203 hospital controls. Food composition tables and ad-hoc estimates of portion sizes were used to derive intake estimates of 29 nutrients and of total calories. Relative risks were calculated for quartiles of consumption of each specific nutrient after adjustment for total calorie intake. Colorectal cancer was found associated with dietary intake of total calories (RRs = 1.0, 1.6, 1.6, 2.6) and cholesterol (RRs = 1.0, 0.9, 1.7, 1.7) and a protective effect was associated with the intake of fibre from legumes (pulses) and folic acid. The associations and the trends were statistically significant. Among the main energy-supplying nutrients, after adjustment for calories from other sources, increased risks were found for protein (RRs = 1.0, 1.1, 1.7, 2.5), notably animal protein, and carbohydrates (RRs = 1.0, 1.5, 1.4, 2.2), whereas no effects were found for increased consumption of lipids or saturated fats.