The obesity and lack of physical activity stemming from Western lifestyles may be driving the rising incidence of colorectal cancer, suggest experts from the American Cancer Society.
In an article published in A Cancer Journal for Clinicians, authors described patterns of colon cancer incidence and mortality based on updated data provided by the International Agency for Research on Cancer. They provided colon cancer incidence and mortality rates for 5 years from 1998 to 2002. [CA Cancer J Clin 2009 Nov-Dec;59(6):366-78]
“Risk factors for colorectal cancer include obesity, a diet low in fruits and vegetables, physical inactivity, and smoking, and as such it was once a disease primarily observed in longstanding developed nations whose populations typically exhibit these factors,” wrote corresponding author Ms. Melissa M. Center.
“However,” she noted, “in recent years, high colorectal cancer rates have been reported in newly developed countries around the globe, in which the risk was once low.”
For example, colorectal cancer rates among males in countries such as the Czech Republic and Slovakia have superseded peak incidence rates seen in developed nations such as New Zealand, Australia and the US, which previously had the highest colon cancer incidence worldwide. The effect of “Westernization” through the consumption of calorie-dense foods and lack of physical activity is most likely to blame for the high colon cancer incidence in economically transitioning Eastern European countries, the authors reported.
High incidence rates for females were seen in New Zealand, Australia and Israel. However, the incidence among females has declined in New Zealand, while it has stabilized in Australia. It is still on the rise in Israel.
High incidence of colon cancer, most likely motivated by environmental and lifestyle factors, was also seen in Asian countries such as Japan and Singapore for both sexes. The authors stated that in Japanese males, for example, the rise in incidence may be due to dietary changes. “Energy intake gradually increased and then remained constant in Japan after World War II, mainly as a result of the increased intake of Western-type foods, which has contributed to increased obesity in Japan,” the authors wrote.
The lowest incidence of colon cancer in both males and females was observed in India (Nagpur, Poona, and Karunagappally), Oman, Egypt (Gharbiah), Algeria (Setif), and Pakistan (South Karachi). “In these economically developing regions of the world, low colorectal cancer incidence rates may reflect a lower prevalence of known risk factors,” the authors stated.
According to a mortality trend analysis, colon cancer deaths had decreased in both sexes in 13 of the 29 countries included in the analysis [countries selected from the WHO mortality database]. These decreases were mostly seen in longstanding, economically developed nations such as the US, UK, the majority of Western Europe, Australia and New Zealand.
Increasing mortality rates from colon cancer were observed in all the South American nations in the analysis (Mexico, Brazil, Chile, and Equador), as well as in Romania and Russia. In China, Croatia, Kazakhstan, Latvia and Spain deaths from colon cancer increased only in males. Of note was the fact that the greatest increase in colon cancer deaths among all the countries in the analysis was seen in Korean women.
The rising number of deaths from colon cancer could “illustrate a lack of colorectal cancer screening programs and interventions to reduce the effects of lifestyle and dietary changes that accompany urbanization,” the authors wrote.
Friday, Mar 24th
Last update:06:42:40 AM GMT