RESUMO
AIMS: Solitary fibrous tumour (SFT) is a rare mesenchymal-derived neoplasm that can arise in any anatomical location in the body. SFT rarely metastasises, but aggressive behaviour is seen in a minority of cases, and relapses can occur several years after treatment. It would be a clinical advantage if high-risk patients could be identified before treatment. MATERIALS AND METHODS: We retrospectively analysed a population-based cohort of SFT to describe treatment, outcome, prognostic factors and to further validate a previously published risk assessment tool (D-score) based on age, tumour size and mitotic index. Seventy-two patients diagnosed with SFT in the Central, North and Southern Denmark regions between 1979 and 2013 were included in the study. RESULTS: For patients with localised disease at the time of diagnosis (n = 64) the 5 and 10 year overall survival was 86% (95% confidence interval 74-92) and 65% (95% confidence interval 50-78), respectively. Seventeen of 62 patients (27%) who were in remission after radical treatment developed recurrence with either local or distant disease. The 5 year recurrence-free survival was 83% (95% confidence interval 70-90) and the 10 year was 69% (95% confidence interval 53-81). The 5 year local recurrence-free survival was 96% (95% confidence interval 86-99) and the 10 year was 92% (95% confidence interval 76-96). The median time to both overall recurrence and local recurrence was 4.3 years. Metastatic or inoperable SFT had a poor prognosis with a median overall survival of 8.4 months (range 3.6-26.4) and a 5 year overall survival of 11% (95% confidence interval 2-30). A further validation of a risk assessment tool (D-score) confirmed that patients classified as high-risk had a significantly decreased overall survival, with a hazard ratio of 3.7 (95% confidence interval 1.1-12.3). CONCLUSIONS: This study showed that our management and outcome were comparable with other published studies describing SFT and confirmed the value of the D-score as a risk assessment tool. Because of late recurrences, long-term (e.g. 10 years) follow-up for moderate- and high-risk patients is recommended.
