11068 Background: Roughly 10% of patients with soft tissue sarcoma (STS) present with synchronous metastases and generally cannot be cured anymore. With the registration of trabectedin, pazopanib and the identification of other agents exerting activity against STS, the treatment of these patients in the Netherlands has changed considerably in the last decade. The aim of this population-based study is to examine whether the overall survival (OS) of patients with STS and synchronous metastases has improved over the years. Methods: All patients diagnosed with adult-type STS and synchronous metastases between 1989 and 2014 were queried from the Netherlands Cancer Registry. Trends in OS were assessed by the Kaplan Meier method and log rank test in different timeframes based on year of registration of trabectedin ( < 2007 vs. ≥2007) and pazopanib ( < 2012 vs. ≥2012). A multivariable Cox regression analysis was performed to identify relevant characteristics prognostic for OS. Results: In total, 1,393 patients with adult-type STS and synchronous metastases were identified. Over the whole time period, median OS did not improve significantly (5.8 months in 1989-1994 to 8.1 months in 2010-2014, p = 0.095), but median OS < 2007 compared to ≥2007 did improve significantly (5.8 months to 7.3 months, p = 0.035). This was particularly apparent in the liposarcoma subgroup, where median OS doubled (5.2 months to 11.5 months, p = 0.020). Median OS < 2012 compared to ≥2012 did not increase significantly (6.1 months to 7.6 months, p = 0.062), though there was a relatively short follow-up of 2 years while the survival curve seems to reach a plateau phase. Aside from not receiving (any type of) treatment, elderly age, STS subtype other than lipo- or leiomyosarcoma, high or unknown grade and nodal involvement were significant negative predictors for OS, whereas primary tumor site in the extremity and surgery in an academic center had a favorable effect on OS. Conclusions: OS of STS patients with synchronous metastases has not improved significantly over the years, except for the subgroup of liposarcomas after 2007. A longer follow-up period is needed to clarify the impact of pazopanib on OS in patients with metastatic STS.
Increased risk of malignancies in a population-based study of 818 soft-tissue sarcoma patients
