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.

The mitochondria-targeted anti-oxidant MitoQ decreases ischemia-reperfusion injury in a murine syngeneic heart transplant model.

BACKGROUND: Free radical production and mitochondrial dysfunction during cardiac graft reperfusion is a major factor in post-transplant ischemia-reperfusion (IR) injury, an important underlying cause of primary graft dysfunction. We therefore assessed the efficacy of the mitochondria-targeted anti-oxidant MitoQ in reducing IR injury in a murine heterotopic cardiac transplant model. METHODS: Hearts from C57BL/6 donor mice were flushed with storage solution alone, solution containing the anti-oxidant MitoQ, or solution containing the non-anti-oxidant decyltriphenylphosphonium control and exposed to short (30 minutes) or prolonged (4 hour) cold preservation before transplantation. Grafts were transplanted into C57BL/6 recipients and analyzed for mitochondrial reactive oxygen species production, oxidative damage, serum troponin, beating score, and inflammatory markers 120 minutes or 24 hours post-transplant. RESULTS: MitoQ was taken up by the heart during cold storage. Prolonged cold preservation of donor hearts before IR increased IR injury (troponin I, beating score) and mitochondrial reactive oxygen species, mitochondrial DNA damage, protein carbonyls, and pro-inflammatory cytokine release 24 hours after transplant. Administration of MitoQ to the donor heart in the storage solution protected against this IR injury by blocking graft oxidative damage and dampening the early pro-inflammatory response in the recipient. CONCLUSIONS: IR after heart transplantation results in mitochondrial oxidative damage that is potentiated by cold ischemia. Supplementing donor graft perfusion with the anti-oxidant MitoQ before transplantation should be studied further to reduce IR-related free radical production, the innate immune response to IR injury, and subsequent donor cardiac injury.