By Spy Uganda
Lifestyle factors are probably contributing to a 79pc increase in new cases of cancer globally among the under-50s over the past three decades, new research shows.
Breast cancer accounted for the highest number of early-onset cases in this age group in 2019, according to research in BMJ Oncology. The overall time frame spans 1990 to 2019.
However, the analysis also showed that cancers of the windpipe and prostate have risen the fastest since 1990.
Cancers leading to the highest death toll and compromising health the most among younger adults in 2019 were those of the breast, windpipe, lung, bowel, and stomach.
The National Cancer Registry in Ireland has separately looked at cancer incidence trends in the under-50 subset in many of its reports. As an example, it used a tool to examine rates of bowel cancer in men and women from 1994 to 2020.
It indicates a gradual increase in the rate of this cancer in the under-50s – now 4.2pc in men and 6.7pc in women per year. More detailed study is required before it can be determined if this stands out as statistically significant.
An editorial in the journal, by doctors from the Centre for Public Health at Queen’s University Belfast, stated: “The global findings upend received wisdom about the types of cancers typically affecting the under-50s.
“The findings… challenge perceptions of the type of cancer diagnosed in younger age groups.
“Full understanding of the reasons driving the observed trends remains elusive, although lifestyle factors are likely contributing, and novel areas of research such as antibiotic usage, the gut microbiome, outdoor air pollution and early-life exposures are being explored.”
They conclude: “Prevention and early-detection measures are urgently required, along with identifying optimal treatment strategies for early-onset cancers, which should include a holistic approach addressing the unique supportive care needs of younger patients.
“There is a pressing need for partnership, collaboration and resource distribution at a global level in order to achieve these aims.”
The authors pointed out genetic factors are likely to have a role. However, the main risk factors underlying the most common cancers among the under-50s are diets high in red meat and salt, and low in fruit and milk, alcohol consumption and tobacco use. Physical inactivity, excess weight, and high blood-sugar levels are also contributory factors.
The study drew on data from the ‘Global Burden of Disease Study’ from 2019, which identified 29 cancers in 204 countries and regions.
In 2019, new cancer diagnoses among the under-50s totalled 3.2 million, an increase of 79pc on the 1990 figure.
Breast cancer accounted for the largest number of these cases as well as associated deaths, with 13.7 cases and 3.5 deaths per 100,000 of the global population.
But new cases of early-onset windpipe and prostate cancers rose the fastest between 1990 and 2019.
More than one million under-50s died of cancer in 2019, an increase of just under 28pc on the 1990 figure.
The highest rates of early-onset cancers in 2019 were in North America, Australasia, and Western Europe. But low-to-middle-income countries were also affected, with the highest death rates among the under-50s in Oceania, Eastern Europe, and Central Asia.