Global burden of colorectal cancer in 2020 and 2040: incidence and mortality estimates from GLOBOCAN

Correspondence to Dr Eileen Morgan, International Agency for Research on Cancer, 69372 Lyon CEDEX 08, France; [email protected]

WHAT IS ALREADY KNOWN ON THIS TOPIC

• Colorectal cancer is the third most common cancer diagnosed worldwide and the second-leading cause of cancer deaths.

• Colorectal cancer is highly preventable with several modifiable risk factors confirmed, including smoking, unhealthy diet, high alcohol consumption, physical inactivity and excess body weight.

• Previous studies have shown that trends in colorectal cancer incidence rates are decreasing in recent years in older adults, largely due to screening and the detection and removal of precancerous lesions in high-income countries. In contrast, rising incidence rates have been observed in younger adults (aged <50 years) and in transitioning countries (across all ages), indicating that changes in risk factor exposures in early life may play a role.

WHAT THIS STUDY ADDS

• This study provides the most recent estimates of the incidence and mortality of colorectal cancer in 185 countries in 2020. We observed large variations in rates across regions, with incidence and mortality rates highest in Europe and lowest in Southern Asia.

• Our study shows that incidence rates in countries of very high Human Development Index (HDI) were four times higher than counterpart countries with low HDI levels. Globally, 60% of cases are diagnosed at ages 50–74 years, and almost 10% occur in adults under 50.

• By 2040, the number of cases of colorectal cancer is predicted to increase to 3.2 million new cases and 1.6 million deaths. Four-fifths of these new cases (81%) are predicted to occur in countries with high or very HDI.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

• Through an assessment of the current global patterns of colorectal cancer, the study highlights the importance of prevention through modifiable risk factors, as well as via the detection and removal of precancerous lesions.

• While colorectal cancer incidence has been decreasing across high-income countries due to effective screening programmes, it remains a commonly diagnosed cancer with increasing rates observed in younger adults and transitioning countries. As such, future research into aetiological risk factors in diverse populations, alongside the implementation of effective primary prevention strategies is warranted to reduce the impact of this preventable disease.

Introduction

Colorectal cancer (CRC) is the third most commonly diagnosed cancer...