The silent surge: Why colon cancer is striking the young
The symptoms of colorectal cancer vary, depending on the location of the tumour. The left colon, being narrower than the right, is more likely to cause symptoms. Photo/Fotosearch
What you need to know:
- Also known as bowel or colorectal cancer, the disease is the only one that registered a sharp rise among the 13 types of cancer initially reported to skyrocket in young adults across nations,
Colon cancer was once considered a disease of the elderly—something that happened to people in their 60s and 70s, not to those in the prime of their youth. But a landmark global study has shattered that assumption, revealing an alarming reality: the disease is surging amongst young people aged below 50 years, globally, including Kenya.
Also known as bowel or colorectal cancer, the disease is the only one that registered a sharp rise among the 13 types of cancer initially reported to skyrocket in young adults across nations, scientists say.
While some of those cancers even decreased in prevalence levels, colon cancer rose drastically in young people aged 20 to 49, compared to adults aged 50 and above, according to the study published this month.
Prostate, kidney, gallbladder, breast, endometrial, thyroid, stomach, pancreatic, liver, colon, oral, oesophageal, and leukaemia are the 13 forms of cancer examined by the United Kingdom-based researchers.
The team engaged 42 countries from Africa (one), Australasia (two), North and South America (six), Asia (11), and Europe (22), using annual data on cancer incidence from the GLOBOCAN database, International Agency for Research on Cancer.
The 15-year-long study between 2003 and 2017 was titled "Trends in Cancer Incidence in Younger and Older Adults: An International Comparative Analysis."
To estimate the Average Annual Percentage Change in cancer incidence rates for the 13 types of cancer, the researchers used the joinpoint regression technique.
Colon cancer is the only one among the 13 cancers that registered a sharp increase in incidence rates among young people below 50 in over half—69 per cent—of the 42 countries engaged, according to the findings.
Prevalence rates
In contrast, reduced prevalence rates were reported in some cancers, like stomach and liver among young adults in more than half of the countries engaged, as indicated by the study published in the Annals of Internal Medicine journal.
The researchers found no "significant differences" in kidney, breast, and thyroid cancer rates between young people and adults.
Colon cancer surged speedily among young adults compared to people aged above 50 in over a third of the countries engaged, scientists explained.
For liver, oral, oesophageal, and stomach cancer, rates decreased in younger adults in more than half the countries.
Overall, five out of the 13 cancers analysed indicated increased incidence rates in both young and older adults in three-quarters of the countries assessed.
"Cancer incidence rates increased for several cancer types in many of the countries studied; however, other than colorectal cancer, these increases occurred in both younger and older adults," the scientists say.
The researchers highlight the findings' significance in informing the public and health guidelines, as well as future research.
However, they clarify that the results may not be replicable because most available data originated from high and middle-income countries.
The study lead, Prof Amy Berrington, explained that colon cancer is the only disease found to be increasing in young people more than in older adults across several nations.
Dr Berrington attributes increased colon cancer prevalence rates in older adults to increased testing and screening, which enables medics to prevent them from contracting the illness.
"It is possible that the difference could be due to routine screening offered to older adults," states the cancer epidemiology clinical expert.
In addition to enabling early cancer detection, screening also helps in cancer prevention through removing pre-malignant lesions, the expert explains.
In Kenya and Africa, colorectal cancer prevalence is escalating among young people, aggravating the growing burden of non-communicable diseases on the continent, according to the World Health Organization (WHO).
WHO attributes late diagnosis and disease advancement, which results in high deaths, to a lack of awareness and screening, exposing Kenyan young people to colon cancer, which experts have linked to lifestyle, dietary, and environmental factors.
Previous studies have linked rising cancer cases in younger adults to increasing obesity rates, but the evidence remains unclear.
Presently, researchers are investigating whether new cancer-causing substances (carcinogens) could be involved in the increase or whether obesity can explain it.
