Epidemiology of colorectal cancer: A review with special emphasis on India

Colorectal cancer (CRC) is a common malignancy and cause for death around the world. In India, it ranks as the fourth most incident cancer in both sexes, with 64,863 cases and 38,367 deaths in 2022. With such high mortality, CRC survival in India is way lesser than that of developed countries. While western countries are facing an overall decline in CRC incidence, various regions in India are seeing an increasing trend. Within India, urban regions have markedly higher incidence than rural. Risk factors include consumption of red and processed meat, fried and sugary food, smoking and alcohol, comorbidities such as obesity, diabetes and inflammatory bowel disease (IBD), family history of CRC, adenomas and genetic syndromes, radiation exposure, pesticides and asbestos. Consumption of nutrient-rich well-balanced diets abundant in vegetables, dairy products, whole grains, nuts and legumes combined with physical activity are protective against CRC. Besides these, metformin, aspirin and micronutrient supplements were inversely associated with the development of CRC. Since a considerable proportion of CRC burden is attributed to modifiable risk factors, execution of population level preventive strategies is essential to limit the growing burden of CRC. Identifying the necessity, in this review, we explore opportunities for primary prevention and for identifying high-risk populations of CRC to control its burden in the near future.