The Danish Sarcoma Database.

Aim: The aim of the database is to gather information about sarcomas treated in Denmark in order to continuously monitor and improve the quality of sarcoma treatment in a local, a national, and an international perspective.

Study Population: Patients in Denmark diagnosed with a sarcoma, both skeletal and ekstraskeletal, are to be registered since 2009.

Main Variables: The database contains information about appearance of symptoms; date of receiving referral to a sarcoma center; date of first visit; whether surgery has been performed elsewhere before referral, diagnosis, and treatment; tumor characteristics such as location, size, malignancy grade, and growth pattern; details on treatment (kind of surgery, amount of radiation therapy, type and duration of chemotherapy); complications of treatment; local recurrence and metastases; and comorbidity. In addition, several quality indicators are registered in order to measure the quality of care provided by the hospitals and make comparisons between hospitals and with international standards.

Descriptive Data: Demographic patient-specific data such as age, sex, region of living, comorbidity, World Health Organization's International Classification of Diseases - tenth edition codes and TNM Classification of Malignant Tumours, and date of death (after yearly coupling to the Danish Civil Registration System). Data quality and completeness are currently secured.

Conclusion: The Danish Sarcoma Database is population based and includes sarcomas occurring in Denmark since 2009. It is a valuable tool for monitoring sarcoma incidence and quality of treatment and its improvement, postoperative complications, and recurrence within 5 years follow-up. The database is also a valuable research tool to study the impact of technical and medical interventions on prognosis of sarcoma patients.