Current practices in spatial analysis of cancer data: mapping health statistics to inform policymakers and the public

Background  

To communicate population-based cancer statistics, cancer researchers have a long tradition of presenting data in a spatial representation, or map. Historically, health data were presented in printed atlases in which the map producer selected the content and format. The availability of geographic information systems (GIS) with comprehensive mapping and spatial analysis capability for desktop and Internet mapping has greatly expanded the number of producers and consumers of health maps, including policymakers and the public.     

Role of circulating gastrin in colorectal adenomas and carcinomas

BACKGROUND/AIMS: A trophic role of gastrin has been convincingly demonstrated in the oxyntic mucosa of the stomach, but is still a matter of debate in the lower gastrointestinal tract. METHODS: In order to examine the role of circulating gastrin in colorectal adenoma and carcinoma fasting serum gastrin concentrations were determined in 351 patients undergoing complete colonoscopy. RESULTS: In comparison to controls (n = 145) more patients with either polyps (n = 125) or colorectal carcinoma (n = 81) have slightly increased serum gastrin concentrations, leading to an increased mean, but no change in median serum gastrin levels. In 3 patients preoperatively increased serum gastrin concentrations were normalized after surgical removal of the polyp and/or tumor, suggesting a local release of gastrin from the polyp/tumor. Gastrin concentrations do not correlate with the histopathological classification or malignant potential of adenomatous polyps. CONCLUSION: In view of these findings a significant role of circulating endogenous gastrin in human colorectal carcinogenesis seems to be unlikely.     

Expression of E-cadherin repressors SNAIL,ZEB1 and ZEB2 by tumour and stromal cells influences tumour-budding phenotype and suggests heterogeneity of stromal cells in pancreatic cancer

Background:

There is evidence that tumour–stroma interactions have a major role in the neoplastic progression of pancreatic ductal adenocarcinoma (PDAC). Tumour budding is thought to reflect the process of epithelial–mesenchymal transition (EMT); however, the relationship between tumour buds and EMT remains unclear. Here we characterize the tumour-budding- and stromal cells in PDAC at protein and mRNA levels concerning factors involved in EMT.

Methods:

mRNA in situ hybridisation and immunostaining for E-cadherin, β-catenin, SNAIL1, ZEB1, ZEB2, N-cadherin and TWIST1 were assessed in the main tumour, tumour buds and tumour stroma on multipunch tissue microarrays from 120 well-characterised PDACs and associated with the clinicopathological features, including peritumoural (PTB) and intratumoural (ITB) budding.

Results:

Tumour-budding cells showed increased levels of ZEB1 (P<0.0001) and ZEB2 (P=0.0119) and reduced E-cadherin and β-catenin (P<0.0001, each) compared with the main tumour. Loss of membranous β-catenin in the main tumour (P=0.0009) and tumour buds (P=0.0053), without nuclear translocation, as well as increased SNAIL1 in tumour and stromal cells (P=0.0002, each) correlated with high PTB. ZEB1 overexpression in the main tumour-budding and stromal cells was associated with high ITB (P=0.0084; 0.0250 and 0.0029, respectively) and high PTB (P=0.0005; 0.0392 and 0.0007, respectively). ZEB2 overexpression in stromal cells correlated with higher pT stage (P=0.03), lymphatic invasion (P=0.0172) and lymph node metastasis (P=0.0152).

Conclusions:

In the tumour microenvironment of phenotypically aggressive PDAC, tumour-budding cells express EMT hallmarks at protein and mRNA levels underlining their EMT-type character and are surrounded by stromal cells expressing high levels of the E-cadherin repressors ZEB1, ZEB2 and SNAIL1, this being strongly associated with the tumour-budding phenotype. Moreover, our findings suggest the existence of subtypes of stromal cells in PDAC with phenotypical and functional heterogeneity.     

Spontaneous Liver Rupture After Treatment With Drug-Eluting Beads

Spontaneous rupture of hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE) is a rare and life-threatening complication. Pathophysiologic mechanisms are not yet fully known; it is suggested that rupture is preceded by reactive tissue edema and intratumerous bleeding, leading to a rapid expansion of tumour mass with risk of extrahepatic bleeding in the case of subcapsular localisation. This case report discusses a sudden, unexpected lethal complication in a 74 year-old male patient treated with TACE using DC Bead loaded with doxorubicin (DEBDOX) in a progressive multifocal HCC.     

Identification and characterization of populations living near high-voltage transmission lines: a pilot study.

Populations living close to high-voltage transmission lines often have residential magnetic field exposures in excess of 1 microT, and sometimes over 2 microT. Yet, populations studied in most epidemiologic investigations of the association between residential magnetic field exposure and cancer typically have exposures below 1 microT and frequently below 0.5 microT. To improve statistical power and precision, it would be useful to compare high exposure populations with low exposure populations rather than only studying small differences within low exposure populations. Toward this end, we have developed an automated method for identifying populations living near high-voltage transmission lines. These populations likely have more highly exposed individuals than the population at large. The method uses a geographic information system (GIS) to superimpose digitized transmission line locations on U.S. Census block location data and then extract relevant demographic data. Analysis of data from a pilot study of the populations residing within 100 m of a 29-km segment of one 230-kV line in New Jersey shows that when compared to populations in the surrounding census blocks farther than 100 m from this line, those populations close to the line have similar demographics but differ in terms of perceived housing value variables. We believe that the approach we have developed will enable investigators to rapidly identify and characterize populations living near high-voltage transmission lines on a statewide basis for considering the impact of exposures and for public policy and that these populations also can be used for epidemiologic study.     

An alternative approach for investigating the carcinogenicity of indoor air pollution: pets as sentinels of environmental cancer risk.

Traditionally, the cancer risks associated with radon,environmental tobacco smoke (ETS), and similar indoor residential exposures have been evaluated through either laboratory experiments in rodents or epidemiology studies in people. Laboratory studies have the advantage of being controlled experiments, but their utility as estimators of human risk is limited by the uncertainties of extrapolating from rodents to people and from high doses to those typically experienced in the home. These experiments also subject animals to noxious exposures, causing suffering that may be considered cruel. Traditional epidemiology studies evaluate human risk directly, at the exposure levels present in residences; however, these studies are limited by their potential for misclassification, biased recall, and uncontrolled confounding. The long time intervals involved between exposure and disease (often 30 years or more) make accurate recall particularly problematic. In this paper we discuss the limitations of these traditional approaches, especially as they relate to residential studies of radon and ETS. The problems associated with the maximum tolerated dose in rodent bioassays and exposure misclassification in traditional epidemiology are particularly examined. A third approach that supplements the traditional approaches and overcomes some of their limitations is suggested. This approach, dubbed pet epidemiology, estimates residential cancer risk by examining the exposure experience of pet dogs with naturally occurring cancers. The history of pet epidemiology is reviewed and its strengths and limitations are examined.     

Sexual differentiation and the germ cell in sex reversed gonads after aromatase inhibition in the chicken embryo.

Chicken embryos were treated on day three of incubation with a steroidal or a non-steroidal aromatase inhibitor (1-methyl-androstendion, CGS 16949 A). Complete sex reversal of ovaries into testes or intermediate stages of sex reversal resulted from the inhibitory effect on oestradiol formation during gonadal development before and during sexual differentiation. Germ cell differentiation shifted from the female to the male pattern depending on the local advance of sex reversal.     

A perceived cluster of amyotrophic lateral sclerosis cases in a Massachusetts community.

We investigated a report of a perceived cluster of amyotrophic lateral sclerosis (ALS) in Middleborough, Mass. Although an increase in ALS incidence was observed [2.51 deaths/100,000 person-years (p-y)], relative to the statewide rate over the years 1969-1985 (1.26/100,000 p-y), it was not statistically significant at the 95% confidence level. Problems in evaluating possible neurological disease clusters and their association with environmental exposures are presented.