 However molecular assessment of the patient and the tumor in the metastatic situation is not performed on a routine basis and in many cases tumor characteristics from the primary tumor are considered reliable enough to make therapy decisions for the metastatic patients. Although molecular reassessment of tumor characteristics from tumor material of the metastasis is recommended in national guidelines, only a minority of patients is biopsied, because of the invasiveness of the procedure, even though biopsy related complications are reported to be rare. 