BACKGROUND: We present work funded by Macmillan Cancer Support and hosted with the UK Acute Oncology Society from conversations about acute cancer care with oncologists, palliative care and generalist clinicians to determine how best to manage the increasing complexity of cancer patients and their management. METHODS: We used a number of facilitated focus groups to draw out themes of initial management, communication differentiating between toxicity, disease progression and when and how to start conversations about the end of life. RESULTS: There is an awareness of the significant mortality for patients needing acute cancer care. However, there is no clear responsibility to having these prognostic conversations. These include attitudes towards future care planning (FCP) in oncology, ownership and the challenges faced by non-oncologists treating more and more people living with cancer. CONCLUSIONS: There needs to be increased recognition of acute admission as a point of transition, often into end-of-life care, for people with cancer. There are significant barriers to conversations in acute cancer care, which include a lack of clear ownership in oncology pathways, and a reticence of all professionals to engage in conversations around prognosis before acute admission or at the time of acute illness. There is a need to develop standardised links between oncology and urgent care providers and for protocols within hospital to allow for access to expertise and assessment and onward sharing of information. Earlier, more transparent conversations may allow patients and families to make clearer choices about care options in the last months of life and, critically, reduce dependence on acute care.