Study predicts alarming increase by 2030

An international team of scientists has recently explored the global burden of early-onset cancers by analyzing the Global Burden of Disease (GBD) 2019 dataset. They have published the study in BMJ Oncology.

Study: Global trends in incidence, death, burden and risk factors of early-onset cancer from 1990 to 2019. Image Credit: Jo Panuwat D / Shutterstock

Background

Cancer is a leading cause of morbidity and mortality worldwide. Global cancer incidence and mortality estimates indicate that breast cancer has the highest prevalence and lung cancer has the highest mortality rate worldwide.

Although late-onset cancers occurring in adults aged over 50 years have a higher prevalence, the global incidence of early-onset cancers, which occur in adults aged lower than 50 years, is gradually increasing with time. Exposure to potential lifestyle and environmental risk factors at an early age may increase the risk of early-onset cancer. Cancer screening strategies are the most effective preventive measures against early-onset cancer and associated disease burden.

In this study, scientists have explored the global burden of early-onset cancer based on the GBD 2019 database, which includes a total of 29 early-onset cancers in 204 countries and regions. Cancer cases diagnosed between 14 and 49 years of age were regarded as early-onset cancers. Specifically, the study assessed the rates of incidence, mortality, disability-adjusted life years, and risk factors associated with early-onset cancers.  

Important observations

The incidence rate of early-onset cancers was 3.26 million per 100,000 population in 2019, which indicated a 79% induction from 1990. The mortality rate of early-onset cancers was one million, which accounted for a 27.7% induction from 1990. The highest rates of mortality and disability-adjusted life years were reported for early-onset breast, tracheal, bronchus and lung, stomach, and colorectal cancers.

The incidence rates of early-onset nasopharyngeal and prostate cancer showed the fastest increasing trend. In contrast, the sharpest decline in incidence rate was observed for early-onset liver cancer. Regarding mortality rates, the fastest increasing trend was observed in early-onset kidney and ovarian cancers, and the sharpest declining trend was observed in early-onset liver cancer.   

Gender-wise cancer burden in 2019

The highest disease burden was observed among women with early-onset breast cancer and men with early-onset tracheal, bronchus, and lung cancers. Overall, the morbidity and mortality of early-onset cancers were lower in men than in women between 1990 and 2019.   

Country-wise cancer burden in 2019

The highest and lowest age-standardized incidence rates of early-onset cancers in 2019 were reported in high-income North America and low-income Western Sub-Saharan Africa, respectively. 

The highest and lowest age-standardized mortality rates of early-onset cancers were reported in Oceania, Eastern Europe, and Central Asia and in high-income Asia Pacific, respectively. The highest and lowest rates of age-standardized disability-adjusted life years of early-onset cancers were reported in Oceania and high-income Asia Pacific, respectively. 

Overall, the highest burden of early-onset cancer was reported in world regions with high-middle and middle Sociodemographic Index (SDI). While the morbidity of early-onset cancer increased with the SDI, a significant reduction in the mortality rate was observed with increasing SDI.  

Risk factors associated with early-onset cancers

For early-onset breast cancer, the leading risk factors associated with disability-adjusted life years included alcohol intake, tobacco smoking, excessive red meat intake, lack of physical activity, and hyperglycemia (high blood glucose).  

For early-onset tracheal, bronchus, and lung cancers, the leading risk factors associated with disability-adjusted life years included tobacco smoking, low fruit intake, and hyperglycemia. For early-onset colorectal cancer, the leading risk factors were dietary risks (a diet rich in red meat, low in fruits, high in sodium, and low in milk), alcohol intake, tobacco smoking, lack of physical activity, high body mass index (BMI) and hyperglycemia. For early-onset stomach cancer, the leading risk factors were tobacco smoking and sodium-enriched diet.

Prediction of incidence and mortality rates of early-onset cancers

The global rates of incidence and mortality of early-onset cancers are predicted to increase by 31% and 21% in 2030, respectively. The age groups of 40–44 years and 45–49 years are predicted to represent a significant proportion of the population affected by early-onset cancer morbidity and mortality in the next 10 years.