BRCA1 in special populations

Metabolic syndrome, obesity, and the risk of cancer development

BACKGROUND

Metabolic syndrome and its components are severe global health issues that are increasing in frequency as the prevalence of obesity increases. Various studies have established a correlation between metabolic syndrome and diseases including, diabetes mellitus, non-alcoholic fatty liver disease, cirrhosis, and cardiovascular disease. In recent years, correlations have also been detected between obesity and metabolic syndrome and the prevalence of certain types of cancer. The current study examines whether obesity and metabolic syndrome components are risk factors for cancer among the adult population in Israel.

METHODS

A cohort study analysis was performed of 24,987 initially healthy men and women who underwent yearly medical assessments at the Institute for Medical Screening in the Sheba Medical Center. Data from the Institute for Medical Screening database was correlated with that from the Israel Cancer Center in the Ministry of Health updated to December 2013. The correlation between metabolic syndrome, obesity, and the overall risk of cancer as well as the risks of specific types of cancer were examined.

RESULTS

Of 20,444 subjects for whom complete data were available, 1535 were diagnosed with cancer during the mean follow-up time of 104.3months. In a multi-variant analysis, no significant correlation was found between metabolic syndrome or obesity and the incidence of cancer. When the data were stratified by gender and cancer type, however, a significant association between metabolic syndrome and breast cancer in women was observed (P=0.03, HR=1.67, 95% CI=1.05-2.67).

CONCLUSION

Metabolic syndrome correlates with higher than expected breast cancer incidence in women.

Cancer biomarker discovery: the entropic hallmark

Background

It is a commonly accepted belief that cancer cells modify their transcriptional state during the progression of the disease. We propose that the progression of cancer cells towards malignant phenotypes can be efficiently tracked using high-throughput technologies that follow the gradual changes observed in the gene expression profiles by employing Shannon's mathematical theory of communication. Methods based on Information Theory can then quantify the divergence of cancer cells' transcriptional profiles from those of normally appearing cells of the originating tissues. The relevance of the proposed methods can be evaluated using microarray datasets available in the public domain but the method is in principle applicable to other high-throughput methods.

Methodology/Principal Findings

Using melanoma and prostate cancer datasets we illustrate how it is possible to employ Shannon Entropy and the Jensen-Shannon divergence to trace the transcriptional changes progression of the disease. We establish how the variations of these two measures correlate with established biomarkers of cancer progression. The Information Theory measures allow us to identify novel biomarkers for both progressive and relatively more sudden transcriptional changes leading to malignant phenotypes. At the same time, the methodology was able to validate a large number of genes and processes that seem to be implicated in the progression of melanoma and prostate cancer.

Conclusions/Significance

We thus present a quantitative guiding rule, a new unifying hallmark of cancer: the cancer cell's transcriptome changes lead to measurable observed transitions of Normalized Shannon Entropy values (as measured by high-througput technologies). At the same time, tumor cells increment their divergence from the normal tissue profile increasing their disorder via creation of states that we might not directly measure. This unifying hallmark allows, via the the Jensen-Shannon divergence, to identify the arrow of time of the processes from the gene expression profiles, and helps to map the phenotypical and molecular hallmarks of specific cancer subtypes. The deep mathematical basis of the approach allows us to suggest that this principle is, hopefully, of general applicability for other diseases.

Ethnicity, genetics, and breast cancer: media portrayal of disease identities

OBJECTIVE

To describe, compare, and analyze how the risk of breast cancer is framed in newspapers directed towards an ethnic minority population (Jewish) with higher risk of inherited breast cancer compared with newspaper coverage for the general population (Anglo-Canadian) without this risk.

DESIGN

This investigation utilized a mixed methods (quantitative and qualitative) approach. The design emphasized a content analysis conducted on ethnically specific and non-ethnic newspaper articles.

RESULTS

It is noteworthy that the 'Jewish' newspapers devote a substantially larger proportion of articles on breast cancer to genetic risk as the key risk factor for this disease. Articles in the Jewish newspapers tend to link being a Jewish woman with being at risk for a diagnosis of breast cancer. This ethnic 'identity' is reinforced through the repeated association of Jewish heritage and genetic breast cancer risk at the exclusion of other known risk factors. This isolated genetic link to breast cancer is not a message that is replicated within the provincial newsprint articles.

CONCLUSIONS

These findings assist in the facilitation of prevention and treatment of those with or at risk of breast cancer. The health policy implications of this portrayal as well as suggestions for change are considered.

Breast cancer mortality among Ashkenazi Jewish women in São Paulo and Porto Alegre, Brazil

BACKGROUND

Increased BRCA1 and BRCA2 germline mutation rates have been reported in Ashkenazi Jewish women in North America, Europe and Israel, and have been mentioned as possibly related to a higher incidence of breast and ovarian cancer among these communities. The present study was carried out with the aim of obtaining evidence on the magnitude of breast cancer as a cause of death among Ashkenazi women in Brazil.

METHODS

We reviewed all death certificates archived in the Jewish Burial Societies of São Paulo (1971-1997) and Porto Alegre (1948-1997), two of the main and oldest Jewish communities in Brazil. Breast cancer observed deaths were compared with expected deaths according to breast cancer mortality in the general population.

RESULTS

The observed ratios were approximately quite close to unity, suggesting a similar breast cancer mortality pattern among the Ashkenazi population and the general population in both cities. These results maintain similar behavior regardless of whether analyzed before or after the mid-1980s, when mammography came to be increasingly performed in Brazil. Cancer proportional mortality ratios were 1.04 (0.83-1.29) in São Paulo and 1.16 (0.84-1.57) in Porto Alegre before 1985, and 1.17 (1.00-1.44) and 1.21 (0.81-1.79), respectively, between 1985 and 1997. Some evidence of the maintenance of protective risk factors such as high parity has been observed among Ashkenazi women in São Paulo.

CONCLUSION

A quite similar breast cancer mortality pattern was observed between Ashkenazi Jewish women and the general population in São Paulo and Porto Alegre, Brazil. These results may suggest an environmental role on germ mutation expression reported in this ethnic group.