OBJECTIVES: Prognostic disclosure among patients with cancer permits open informed discussion about treatment preferences and encourages advance care planning. In rare cancers such as soft tissue sarcoma, discussions regarding prognostication are challenging. Little is known about the consequences of this for patients or their preferences for such information. This qualitative study explores patient-centered accounts of the value and timing of prognostic discussions. METHODS: 24 semistructured interviews were conducted with soft tissue sarcoma patients attending one London cancer centre: 66% female, median age 53 (range 19-82). The study was cross-sectional and participants were at different stages of the advanced disease trajectory. Interviews were digitally recorded, transcribed verbatim and analysed thematically using the framework approach. RESULTS: All participants understood the incurable nature of advanced sarcoma. However, prognostic discussions were rare, always patient initiated and did not include known survival data, despite direct participant enquiry. Most participants did not wish to discuss prognosis at initial diagnosis but wished to be offered the opportunity to discuss this at intervals of disease progression, despite reservations it may not be helpful. Participants expected discussions to be clinician initiated. Three themes emerged to explain this position and included (1) Rarity causing prognostic uncertainty referring to patient belief that prognostication in rare cancers was less likely to be accurate than for common tumours; (2) Avoiding the negatives referring to a wish not to hear unfavourable information and (3) Physical symptoms a better prognostic indicator than ‘physician guess’. CONCLUSIONS: Although 17/24 participants preferred not to discuss prognosis at initial diagnosis, they wished to have the opportunity to revisit prognostic discussions at intervals of disease progression. This may facilitate better advance care planning and end of life care.