GISAR German Interdisciplinary Sarcoma Registry

Sarcomas are rare malignant tumors that affect people of all ages. They can be divided into different subtypes yet having more than 80 different forms of soft tissue sarcomas only. In these terms, it is not remarkable that this high number of subtypes is accompanied by various treatment strategies, often representing multimodal treatments.

In addition, in a growing amount of patients tumors are diagnosed, whose malignant cells have histological, cytological, or molecular properties of both epithelial tumors ("carcinoma") and mesenchymal tumors ("sarcoma").

Such "mixed" sarcomatoid/epithelial tumors ("CS") are categorized as carcinoma considering their epithelial origin. But in most cases, CS seem to be more aggressive, than other carcinomas with the same origin; often they are characterized by rapid growth, invasion, disease recurrence and metastases.

Due to the rarity of CS, only limited information is available about their clinical course and best therapeutic approaches. Because of these uncertainties and the sarcoma-component of the tumors, several CS-patients are referred to sarcomacenters. As many experiences with single CS-cases as possible should be collected and evaluated to better understand the different CS-forms.

Due to the complexity of diagnosis and therapy of sarcomas and of CS it is of high relevance to depict the current treatment landscape and the effects and course of different treatment options to illuminate the best option for each specific patient. This is compassed by this registry, as it aims to collect information and data on treatment and outcome of most of future German sarcoma cases along with retrospective data collection to achieve a most comprehensive data set as well as the possibility to identify alterations / trends in the procedures used for sarcoma diagnosis and therapy over time.