Prospective multicenter registration of major late sequelae in sarcoma patients using the Late Effects Surveillance System (LESS)

Background: Late effects become progressively more important for the evaluation of therapeutic success in paediatric oncology. Thus, in 1998, the Late Effects Surveillance System (LESS) started to register and assess multicentrally, prospectively and longitudinally late effects of treatment for the group of Ewing's, soft tissue- and osteosarcoma patients. Patients and Methods: The yearly results of the follow-up examinations of 785 Ewing's, soft tissue- and osteosarcoma patients, who were treated from 1.1.1998 until 31.12.2001, were prompted and assessed conforming to the guidelines developed by the LESS-study. Results: 136/181 (75%) of follow-up institutions take part in the LESS-study. Only 8% of patients eligible for the LESS-study were cared for in non-cooperating facilities. Questionnaire return could be raised to 73-78% and data completeness could also be significantly improved in the course of the study. Departments of internal medicine had a lower questionnaire return percentage than departments of paediatrics. Data availability for the nephrologic after-care was not satisfactory. Conclusions: The LESS project has been well established. Thus, the basis has been set for the development of risk-oriented strategies for intervention and for the further improvement of the follow-up of major late effects in sarcoma patients.