Risk Of Cancer In Areas Research Articles

Thyroid Cancer Risk in Areas of Ukraine and Belarus Affected by the Chernobyl Accident

The purpose of the present study was to analyze the thyroid cancer incidence risk after the Chernobyl accident and its degree of dependence on time and age. Data were analyzed for 1034 settlements in Ukraine and Belarus, in which more than 10 measurements of the (131)I content in human thyroids had been performed in May/June 1986. Thyroid doses due to the Chernobyl accident were assessed for the birth years 1968-1985 and related to thyroid cancers that were surgically removed during the period 1990-2001. The central estimate for the linear coefficient of the EAR dose response was 2.66 (95% CI: 2.19; 3.13) cases per 10(4) PY-Gy; for the quadratic coefficient, it was -0.145 (95% CI: -0.171; -0.119) cases per 10(4) PY-Gy(2). The EAR was found to be higher for females than for males by a factor of 1.4. It decreased with age at exposure and increased with age attained. The central estimate for the linear coefficient of the ERR dose response was 18.9 (95% CI: 11.1; 26.7) Gy(-1); for the quadratic coefficient, it was -1.03 (95% CI: -1.46; -0.60) Gy(-2). The ERR was found to be smaller for females than for males by a factor of 3.8 and decreased strongly with age at exposure. Both EAR and ERR were higher in the Belarusian settlements than in the Ukrainian settlements. In contrast to ERR, EAR increases with time after exposure. At the end of the observation period, excess risk estimates were found to be close to those observed in a major pooled analysis of seven studies of childhood thyroid cancer after external exposures.

Review article: indication and type of surgery in Crohn's disease.

The large majority of patients affected by Crohn's disease require surgery during their clinical history. Radical resection originally advocated for Crohn's disease does not decrease the recurrence rate, and repeated resections predispose patients to the development of short-bowel syndrome. Over the last few years, conservative surgery has become accepted by many authors as a safe means of treating obstructive Crohn's disease. In this review article we analyse the efficacy and safety of conservative techniques, in comparison with resective surgery. Indications, advantages and technical aspects of resective and conservative surgery are reported. The experience with 489 patients treated for complicated or treatment refractory Crohn's disease in our Institution suggests that strictureplasty is a safe and effective procedure in many cases, as reported by other authors. The risk of cancer in areas of active disease as in stenosis treated with strictureplasty seems to be negligible. Resective surgery still represents the 'gold standard' in patients with perforating Crohn's disease; however, conservative surgery, usually contraindicated in perforating Crohn's disease, can be advocated in patients with localized perforating disease presenting an actual risk of short bowel syndrome.

Cancer Incidence around an Oil Refinery as an Example of a Small Area Study Based on Map Coordinates

The aim of the study was to create a rapid method for estimating cancer risk in areas defined by exact map coordinates and to test it using as an example incidence of leukemia near an oil refinery. The method can be used to investigate possible local excesses of cancer of suspected environmental origin in Finland. Map coordinates with an accuracy of 10 m for the place of residence of each Finn were obtained from national registers. Based on this data set, numbers of inhabitants and expected number of cancer cases by sex and age in squares of 500 × 500 m were calculated for all of Finland. Observed number of cancer cases in each square were obtained based on record Linkage of the map coordinates with the Finnish Cancer Registry. The ratio of observed and expected number of cancer cases was modeled using Poisson regression. The example analysis included all 23 leukemia and 531 any cancer cases registered in an area around an oil refinery in 1983-1986. There was no significant association between distance from the oil refinery and risk of leukemia or any cancer. The method proved fast and efficient in comparing areal differences in cancer incidence in Finland. In cases of environmental concern, geographical analyses of existing registers is a rapid method to perform first analyses when evaluating the need for further studies.