High-burden Cancers in Middle-income Countries: A Review of Prevention and Early Detection Strategies Targeting At-risk Populations.

Cancer incidence is rising in low- and especially middle-income countries (MIC), driven primarily by four high-burden cancers (breast, cervix, lung, colorectal). By 2030, more than two-thirds of all cancer deaths will occur in MICs. Prevention and early detection are required alongside efforts to improve access to cancer treatment. Successful strategies for decreasing cancer mortality in high-income countries are not always effective, feasible or affordable in other countries. In this review, we evaluate strategies for prevention and early detection of breast, cervix, lung, and colorectal cancers, focusing on modifiable risk factors and high-risk subpopulations. Tobacco taxation, human papilloma virus vaccination, cervical cancer screen-and-treat strategies, and efforts to reduce patient and health system-related delays in the early detection of breast and colorectal cancer represent the highest yield strategies for advancing cancer control in many MICs. An initial focus on high-risk populations is appropriate, with increasing population coverage as resources allow. These strategies can deliver significant cancer mortality gains, and serve as a foundation from which countries can develop comprehensive cancer control programs. Investment in national cancer surveillance infrastructure is needed; the absence of national cancer data to identify at-risk groups remains a barrier to the development of context-specific cancer control strategies.