Fragmentation of health care and poor quality primary care in Latin America are the main causes of delays in cancer diagnosis and treatment, contributing to high and steadily increasing mortality rates, especially among disadvantaged populations (e.g. in terms of socio-economic status). Data from Latin America suggest that most delays occur between the initial consultation and confirmation of cancer diagnosis. Integrated care interventions to strengthen primary care and increase coordination of care between levels of care have been shown to be effective in improving early cancer diagnosis, particularly in high-income countries, and are also promoted by national cancer plans in Latin America, but implementation and evaluation are limited. A participatory approach, involving key stakeholders in the adaptation of the intervention, confers greater relevance and contextual validity to the intervention, facilitates its integration into clinical practice and its sustainability over time. Operational research, using a participatory approach, is therefore essential to generate evidence on the effectiveness and costs of implementing integrated care interventions in real-world conditions that can be translated into effective policies for a variety of socio-economic contexts and diverse health systems.