In the last few years, deeper biological understanding of desmoid tumors has led to promising drugs such as sorafenib, mTOR and Notch inhibitors that are currently in clinical trials. These and other drugs cause both tumor reduction and improvement in quality of life. Tumor reduction is measured by standard images and by established criteria (RECIST or WHO). However, the improvement in quality of life described by patients is lost as there are no validated tools to measure this drug effect. The classical regulatory (FDA) pathway to approving new drugs in cancer is demonstration of improvement in overall survival. Surrogates of overall survival include progression free survival and durable tumor responses. An emerging endpoint for regulatory approval is patient reported outcomes (PRO) tools. We believe that development of a PRO tool in desmoid tumors will facilitate a new regulatory endpoint that can be used in all future clinical trials and will be a great investment of resources to advance the field for researchers worldwide.
As of January, there are already requests for PRO to be translated in Japanese and German to be used internationally.