An epidemiological study in England shows an increase in cases of colorectal cancer in young adults as early as their 20s.
Although colorectal cancer is typically associated with older
age-groups, a recent study has found that there is an increase in cases of
colorectal cancer in young people between the ages of 20 to 49.
In Canada, colorectal cancer is the third most prevalent
cancer among the population. Estimates
are that over 12% of all cancers diagnosed in 2020 will be colorectal
cancers. Most of the cases occur in
people aged 50 or older, and the older a person gets, the greater their risk of
contracting this disease. This is why
doctors recommend colonoscopies, a test to examine the inside of a colon, as
well as newer non-invasive tests for patients aged 50 and older.
There are many factors that have been shown to increase the risk of colorectal cancer in the general population. These include a family history of colorectal cancer, a family or personal history of polyps (non-cancerous growths), diet, exercise levels, smoking, and alcohol consumption. This means that there is a combination of genetic risk factors and environmental factors that can contribute to the growth of cancerous cells.
It seems that colon cancer may not remain a disease common
only to older adults. A recent study
from England has shown that there is an increase in the number of new cases of
colorectal cancer in young adults.
Researchers examined documented cases of colorectal cancers
over a 30-year period, from 1985 to 2015, using a database that keeps track of
cancer cases in England. They looked at
the ages of the affected patients and the location of their cancers, as well as
the patients’ gender, geographic location, and their estimated socioeconomic
status. In total, they examined over 1.1
million cases of colorectal cancers over the 30-year span. What they found is that there has been an
overall increase in the trends of diagnoses of colorectal cancer in young
The researchers then examined factors that could affect these trends across the population. They found that the incidences were similar between men and women, and did not change based on the geographic location or the estimated socioeconomic status of the patients. This surprised them, since a common risk factor for cancer is obesity, and there is often a higher incidence of childhood obesity in lower socioeconomic areas.
However, according to the researchers, there has been an
overall increase in obesity among English youth, regardless of socioeconomic
status. This could go a long way to
explaining the increase in colorectal cancer diagnoses seen in young
adults. Yet, this is only one of many
risk factors, and it cannot fully explain the increased incidence.
For example, the researchers found that there was a slightly higher incidence in the South of England as compared to Northern England, despite the South of England benefiting from an overall higher socioeconomic status. The researchers believe this is due to the fact that the population of Southern England has slightly better access to medical services. This can lead to more cases being detected earlier in the patients’ lives and it would explain some of the differences in the age of diagnoses.
While there is no clear-cut answer as to why there has been
an increase in colorectal cancer in young adults, the trend is definitely
moving upwards, and medicine will have to adapt to this in order to respond to
the needs of all future colorectal cancer patients.
Written by Nancy Lemieux
1. Study reveals rising colorectal
cancer rates among young adults. (2020). Retrieved 16 March 2020, from
2. Chambers, A. (2020). Demographic trends in the incidence of young‐onset colorectal cancer: a population‐based study. Retrieved 16 March 2020, from https://bjssjournals.onlinelibrary.wiley.com/doi/full/10.1002/bjs.11486
3. What is colorectal cancer? – Canadian Cancer Society. (2020). Retrieved 16 March 2020, from https://www.cancer.ca/en/cancer-information/cancer-type/colorectal/colorectal-cancer/?region=on
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