International collaboration has undoubtedly played a key role in the extraordinary progress we have witnessed in some areas of oncology in recent years. It has allowed us, for instance, to design trials large enough to depict very small benefits, as well as high-quality trials in less incident types of cancer. For different reasons, developing countries have also shown growing interest in this international effort and have been participating in many international trials. However, the ever-growing costs of novel anti-cancer treatments and technologies have created unprecedented difficulties for health economies in developing countries. Although the issue of individual benefit for patients must also be taken into account, the actual benefit for their society may be minimal. This paper discusses the ethics of including patients from non-developed countries in clinical trials evaluating the role of treatments that are unlikely to be made available to them after the trial because of prohibitive costs. Upfront arrangements ensuring post-trial access to interventions that have been proven successful might be the best alternative to exclusion from the research.