Characteristics, treatment and survival of patients with chondrosarcoma in five European countries: a DARWIN EU® cohort study.

background and purposeChondrosarcoma is a rare bone malignancy with a poor response to systemic therapy in advanced stages. European-level epidemiological data remain scarce. This study aimed to characterise patient demographics, treatments and survival using real-world data to inform regulatory decisions about the feasibility and design of new trials for the systemic treatment of chondrosarcoma. Patient/material and methods: This cohort study, part of the DARWIN EU® initiative, analysed data from six healthcare databases in Finland, France, the Netherlands, Spain and the UK. Patients diagnosed with chondrosarcoma between 2010 and 2022 were identified. Standardised analyses were performed within a federated network using the Observational Medical Outcomes Partnership (OMOP) Common Data Model.

resultsA total of 2,498 chondrosarcoma patient records were identified, covering at least 2,356 unique patients. Median age at diagnosis was 52-55 years, with a balanced sex distribution. Surgical treatment was the most common intervention, recorded in 15.2% to 88.9% of patients, depending on the database. Fewer than 5% received systemic anticancer therapy, and radiotherapy was reported in fewer than 7%. The 10-year overall survival (OS) ranged from 58% (95% confidence interval [CI]: 43-78) to 80% (95% CI: 78-82), with restricted mean survival between 7.4 and 8.7 years. In the Netherlands, patients with late-stage, metastatic or high-grade disease showed significantly poorer outcomes.

interpretationThis study demonstrates the feasibility of using real-world data across Europe to describe chondrosarcoma patients. Most had early-stage, low-grade disease amenable to surgery, with limited use of systemic therapies. Survival was generally favourable, except in advanced disease. Clinical trials remain difficult due to the rarity of advanced chondrosarcoma and the lack of standards.