Early detection, cancer prevention, management and treatment have improved over the years in high-income countries with decreasing mortality and improved survival rates. However, the situation is different in low and middle-income countries (LMICs).
With the rising population and exposure to risk factors, the number of new cancer incident cases has been rising significantly in LMICs in recent years. The survival rate of different cancers is lower in LMICs as they lack early detection programs, disease prevention, cost-effective treatment and oncologic infrastructure. Early diagnosis of cancers is important for treatment options. However, LMICs lack access to early diagnosis, which results in higher mortality rates of several cancers in comparison with infectious diseases or malnutrition. For example, effective low-cost screening methods for breast cancer are scarcely available in LMICs.
Besides, the insufficient prevention, detection and treatment of infectious diseases also increases the risk of few cancers in the LMICs. Therefore, elucidating the burden and risk factors of cancers, which help in prevention and early detection is critical in LMICs to reduce cancer mortality and boost survival rates.
Although cancer incidence and mortality rates are increasing in LMICs, there is a paucity of studies characterizing the geographic distribution and determinants of cancer among these countries. A recent study examined the cancer burden in Africa by the way of spatial epidemiology and also investigated the association between cancer burden and socioeconomic status of African countries. It has been found that almost 1.1 million new cases and 711,429 deaths occurred in 2020 because of cancers and human development index had a significant negative correlation with the mortality-to-incidence ratio (MIR). Furthermore, it was predicted that if the age-specific rates of cancers remain the same, then just because of rising population and changing demographics, the cancer burden will increase to 2.1 million new cases and 1.4 million deaths by 2040 in Africa. The study suggested that the cancer burden in African countries would increase even more than the predicted values by 2040 unless a holistic approach to cancer management and control is adopted in LMICs of Africa. Another study examining the burden of childhood cancers in 183 countries found that ~80% of the global burden of childhood cancers is experienced by the LMICs.
In Asia, the cancer incidence and mortality rates are also increasing. A recent study predicted the future mortality risk of breast cancer among East and South Asian (ESA) countries and identified the risk-attributable mortality caused by the breast cancer. It has been found that the number of deaths caused by breast cancer will increase in the next 10 years in the ESA region. It was predicted that the age-standardized death rate of breast cancer will increase by 7.0% in East Asia, and 35.0% in South Asia from 1990 to 2030.
Moreover, breast cancer mortality risk will increase in low-to-middle sociodemographic index countries in the region. It was suggested that early detection, cost-effective and timely treatment should be provided, and awareness must be increased to deal with rising breast cancer burden in ESA countries. Another study examining the breast cancer burden in Asia found that due to late-disease presentation, lack of screening options and lower availability of treatment options, the mortality rates are higher and survival rates are lower in LMICs of Asia.
A Guest Editorial