The incidence of colorectal cancer (CRC) is increasing in many countries around the world, according to a new study by the American Cancer Society. The study's authors believe the rise is due to the uptake of so-called 'western' diets and lifestyles, such as high red meat consumption and low levels of exercise. Previous studies have documented significant variations in CRC incidence rates and trends, regionally and across countries. However, no study has examined the worldwide pattern using the most recently updated incidence data from the International Agency for Research on Cancer (IARC).
Scientists reviewed data from 51 cancer registries around the world using databases created by the IARC in order to analyse rates of CRC from 1983 to 1987 through to 1998 to 2002. They found that CRC incidence rates statistically significantly increased for both men and women in 27 of the 51 cancer registries, although the increases were more prominent among men. Of particular note were Slovakia, Slovenia and the Czech Republic in the EU, and Japan, Kuwait and Israel in Asia. In Slovenia, CRC incidence increased by 70 per cent among men and 28 per cent among women, and in Miyagi, Japan, rates in men and women rose by 92 and 47 per cent, respectively.
The researchers, whose findings are published in the June edition of Cancer Epidemiology Biomarkers and Prevention (CEBP; 2009;18:1688-1694), also found that there were substantial variations in CRC incidences between different regional and ethnic groups in some countries, including Japan, Israel and Singapore. The only country where CRC rates statistically significantly declined in both sexes was the US, but the US had a very high rate of CRC to start with. In contrast, economically transitioning countries, such as eastern European nations, most parts of Asia and some South American countries, saw large rises in CRC rates. The study authors believe that this may reflect the increasing adoption of western lifestyles and behaviours in these countries.
Further, a separate study, also published in the same edition of CEBP (2009;18:1695-1698), has focused on the CRC incidence rates among young men and women in the US. The recent, accelerated decline in CRC incidence rates has largely been attributed to an increase in screening among adults aged 50 years and older. Scientists used data to report on CRC incidence trends from 1992 through 2005 among adults under the age of 50 years, for whom screening is not recommended for persons at average risk, by sex, race/ethnicity, age, stage at diagnosis and anatomic subsite.
Overall, incidence rates of CRC per 100,000 young individuals (ages 20 to 49 years) increased 1.5 and 1.6 per cent per year in men and women, respectively, from 1992 to 2005. Among non-Hispanic whites, rates increased for both men and women in each ten-year age grouping (20 to 29, 30 to 39 and 40 to 49 years) and for every stage of diagnosis. In contrast to the overall decreasing trend in CRC incidence in the US, rates are increasing among men and women under the age of 50 years. Further studies are necessary to elucidate causes for this trend, and identify potential prevention and early detection strategies.
Alice Rossiter - Cancer Drug News Editor
Showing posts with label colorectal cancer. Show all posts
Showing posts with label colorectal cancer. Show all posts
Wednesday, June 24, 2009
Friday, May 16, 2008
Gender survival differences linked to EGFr variants
A study by researchers at the University of Southern California (USC) and Keck School of Medicine has found evidence that supports gender-related differences in the development and survival of metastatic colorectal cancer (CRC). The study, which was published in the 15th April edition of Cancer Research (2008;68:3037-3042), found that specific gene variants in EGFr linked to the development of CRC resulted in opposite survival outcomes for men and women.
Germline variations in EGFr DNA have been linked with poor prognosis in CRC, however, when researchers looked at EGFr as a prognostic factor, they found that it had opposite implications for men and women. The scientists expected to find that high expression would correlate with a poor prognosis and faster growth of the cancer. What they found, however, was that men followed the expected trend, while women's response was the opposite.
In the study, researchers analysed 318 patients (177 men and 141 women) with metastatic CRC that were treated at the USC/Norris Comprehensive Cancer Center and the LAC+USC Medical Center between 1992 and 2003. The team studied two independent functional polymorphisms of EGFr, one at codon 497 in the extracellular domain of the EGFr gene and the other related to dinucleotide repeats within intron 1. All the patients were exposed to similar chemotherapy treatments. When genomic DNA samples were analysed, the investigators found that women who had specific gene variants linked with high expression of EGFr had higher overall survival (OS) rates, while men with the same variants had lower survival.
Specifically, median OS in men with the Arg/Arg variant of the 497 polymorphism was 10.3 months, while for those with a Lys allele it was 13.7 months. Among women, the corresponding figures were 16.0 and 14.0 months. For the intron polymorphism, a repeat length <20>20. The corresponding survival rates for women were 17.6 and 14.1 months.
According to Dr Heinz-Josef Lenz, Professor of Medicine at the Keck School of Medicine: "This is the first report to show that the prognostic value of EGFr depends on gender. This may suggest that, in the future, molecular markers should be evaluated differently in women and men and that treatment decisions may depend on gender and not only on molecular or clinical findings."
As to mechanisms that might explain these differences, the researchers point out that the colon expresses both oestrogen receptor beta and androgen receptor, and that EGFr interacts with both. Therefore, EGFr may have molecular intermediates that interact in a gender-specific way to effect EGFr pathway activation. Previous research has shown a protective effect of female hormones in CRC survival. The new findings indicate that hormone receptors are important in signal pathways related to the survival of patients. Research will now need to be performed to determine whether men and women respond differently to certain cancer therapies. This may lead to targeted chemotherapy that is tailored to get the best response from male and female patients.
Matthew Dennis - Editor, Cancer Drug News
Germline variations in EGFr DNA have been linked with poor prognosis in CRC, however, when researchers looked at EGFr as a prognostic factor, they found that it had opposite implications for men and women. The scientists expected to find that high expression would correlate with a poor prognosis and faster growth of the cancer. What they found, however, was that men followed the expected trend, while women's response was the opposite.
In the study, researchers analysed 318 patients (177 men and 141 women) with metastatic CRC that were treated at the USC/Norris Comprehensive Cancer Center and the LAC+USC Medical Center between 1992 and 2003. The team studied two independent functional polymorphisms of EGFr, one at codon 497 in the extracellular domain of the EGFr gene and the other related to dinucleotide repeats within intron 1. All the patients were exposed to similar chemotherapy treatments. When genomic DNA samples were analysed, the investigators found that women who had specific gene variants linked with high expression of EGFr had higher overall survival (OS) rates, while men with the same variants had lower survival.
Specifically, median OS in men with the Arg/Arg variant of the 497 polymorphism was 10.3 months, while for those with a Lys allele it was 13.7 months. Among women, the corresponding figures were 16.0 and 14.0 months. For the intron polymorphism, a repeat length <20>20. The corresponding survival rates for women were 17.6 and 14.1 months.
According to Dr Heinz-Josef Lenz, Professor of Medicine at the Keck School of Medicine: "This is the first report to show that the prognostic value of EGFr depends on gender. This may suggest that, in the future, molecular markers should be evaluated differently in women and men and that treatment decisions may depend on gender and not only on molecular or clinical findings."
As to mechanisms that might explain these differences, the researchers point out that the colon expresses both oestrogen receptor beta and androgen receptor, and that EGFr interacts with both. Therefore, EGFr may have molecular intermediates that interact in a gender-specific way to effect EGFr pathway activation. Previous research has shown a protective effect of female hormones in CRC survival. The new findings indicate that hormone receptors are important in signal pathways related to the survival of patients. Research will now need to be performed to determine whether men and women respond differently to certain cancer therapies. This may lead to targeted chemotherapy that is tailored to get the best response from male and female patients.
Matthew Dennis - Editor, Cancer Drug News
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