We have carefully read the letter from Illescas-Vacas et al. regarding SEOM-SEMICYUC's commitment to optimize the care of cancer patients admitted to Intensive Care Units.1,2 We agree with the authors that radiotherapy has evolved with important technological advances in recent years, with more precise, effective and less toxic treatments that contribute to improve survival. Likewise, radiotherapy, in general, is associated with low acute potential toxicity if administered in monotherapy, without concomitant systemic treatment. On the contrary, systemic cancer treatments, chemotherapy, anti-target agents and immunotherapy, among others, have made it possible for a group of patients with advanced disease becoming long-term survivors. Nevertheless, these drugs not only bring new opportunities for patients, but also new challenges and toxicities, creating greater complexity and uncertainty in the field of critical care. In the previous decade, when the prognosis was universally bleak, decision-making was simple, the only solution often being palliative care. However, admission and support in the Intensive Care Unit of a patient with metastatic cancer may currently be justified if it is known that his tumor expresses a target for which specific treatment is available. In addition, a patient with advanced cancer who develops severe toxicity while receiving immunotherapy may require advanced supportive care if a tumor response has been confirmed. These oncological situations and emergencies, which are increasingly common nowadays, have led the SEOM-SEMICYUC team to develop an informative document in which they comment on the oncological scenarios and treatments that are most associated with an acute or emergency condition, something that is especially common in advanced cancers with systemic treatments. This paper shows the two great challenges that technology is imposing on clinical decision making: (1) to correctly transmit information between professionals on individualized prognosis, sometimes based on complex biomarkers,3 (2) to assume that sometimes we will have lost our ability to identify which patients are going to be long-term survivors, so we will be required to provide many of them with adequate support.3,4