Cancer represents a fast-growing challenge worldwide, and is being recognized as an emerging and critical issue in low- and middle-income countries, such most of South America. This subcontinent is unique for its geography, culture, and ethnical diversity. Most of its countries have large expanses of jungle and desert where underserved population groups including indigenous (native Indians), represent a challenge for cancer care. Many indigent patients have no access to preventive care nor early diagnosis. This results in late presentations with advanced disease and frequently incurable cancer. Prompt and coordinated action from local and international organizations is needed to support and guide local governments to avoid a global crisis. The critical role of education to improve awareness of the importance of radiation therapy, a cost-effective treatment modality, with the potential to help these patients at a relatively low cost is discussed.