Highlights
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- We analyzed trends in incidence of colorectal cancer in young adults in Canada.
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- Incidence rate for colorectal cancer has been increasing since the mid-1990’s in young adults.
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- We analyzed trends in modifiable risk factors for colorectal cancer in Canada.
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- The prevalence of excess weight has also been increasing in young adults.
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- Excess weight may have likely played a role in rising colorectal cancer incidence.
Abstract
Background
While
the overall incidence rate of colorectal cancer (CRC) in Canada has
been decreasing, some countries show an increasing incidence in those
under the age of 50. We examined the trends in CRC incidence and
associated lifestyle risk factors in Canadians aged 15–49.
Methods
Incidence
data for colorectal, colon and rectum/rectosigmoid cancers were
obtained for 1969–2010 from the Canadian Cancer Registry, and trends in
age-standardized incidence rates (ASIRs) were examined by Joinpoint
regression for three age groups (15–29, 30–39, 40–49 years) and by sex.
Trends in the prevalence of some CRC risk factors were similarly
examined from national health surveys for various periods ranging from
1970 to 2012.
Results
In both
sexes combined, ASIRs rose by 6.7%/year (1997–2010) for 15–29-year-olds,
2.4%/year (1996–2010) for 30–39-year-olds, and 0.8%/year (1997–2010)
for 40–49-year-olds. Similar trends were observed by sex. The rise in
ASIR was more rapid for cancers of the rectum/rectosigmoid compared to
colon for all age groups. Risk factor trends varied: excess weight rose
substantially, vegetables and fruit consumption increased slightly,
physical inactivity rates declined but remained high, alcohol
consumption changed little, and smoking rates declined. Data on
red/processed meat consumption were unavailable.
Conclusion
The
ASIR of CRC in young Canadians has increased since about the mid-1990s.
The rising prevalence of excess weight in younger generations has
likely played a role in the CRC trend, but more research is needed.
Keywords
- Colorectal cancer;
- Incidence;
- Young adults;
- Risk factors;
- Canada
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