In the past three decades, there has been a notable global increase in the diagnosis of cancer among individuals under the age of 50, though the reasons for this spike remain somewhat unclear, as revealed by a new study published on Wednesday.
The study, featured in the journal BMJ Oncology, demonstrates that cancer cases among those aged 14 to 49 have surged by nearly 80%, soaring from 1.82 million to 3.26 million, spanning from 1990 to 2019.
While experts acknowledge that some of this increase can be attributed to population growth, previous research has also pointed to a growing prevalence of cancer diagnoses in the under-50 age group.
The international team of researchers responsible for this new study has identified poor dietary habits, smoking, and alcohol consumption as significant risk factors associated with cancer in this age group. However, they noted that the exact reasons behind the escalating trend in early-onset cancer cases remain uncertain.
In 2019, slightly over one million people under the age of 50 succumbed to cancer, marking a 28% increase compared to 1990, as indicated by the study.
The most fatal types of cancer in this age group included breast cancer, windpipe cancer, lung cancer, bowel cancer, and stomach cancer, with breast cancer being the most commonly diagnosed over the three-decade period.
Notably, cancers of the nasopharynx (located where the back of the nose meets the top of the throat) and prostate exhibited the most rapid increase.
The study, based on data from the 2019 Global Burden of Disease Study, examined cancer rates across 204 countries, finding that more developed nations tended to have higher rates of cancer diagnoses among those under 50.
This suggests that wealthier countries with robust healthcare systems may be more adept at early cancer detection. Nevertheless, the study also highlighted that only a handful of nations conduct specific cancer screenings for individuals under 50.
In addition to dietary factors, smoking, and alcohol consumption, the study posited that genetic factors, physical inactivity, and obesity may contribute to this trend. Predictive models suggest that global cancer cases among individuals under 50 will further increase by 31% by 2030, primarily among those aged 40-49.
It is essential to acknowledge that cancer data varied significantly between countries, with developing nations potentially under reporting cases and deaths.
Experts not directly involved in the study noted that the relatively slower increase in cancer-related deaths compared to cases could be attributed to improvements in early detection and treatment. Researchers also pointed out that the world's population grew by approximately 46% between 1990 and 2019, accounting for a portion of the rising cases.
Two doctors from Queen's University Belfast, Ashleigh Hamilton and Helen Coleman, emphasised the importance of understanding the factors driving this upward trend.
They suggested that while lifestyle factors likely play a role, ongoing research is exploring novel areas such as antibiotic usage, the gut microbiome, outdoor air pollution, and early-life exposures to gain a comprehensive understanding of the underlying causes.