ORIGINAL ARTICLESS100β protein in peripheral blood may predict progressive disease during interleukin-2 based immunotherapy in patients with metastatic melanomaSchmidt, Henrika; Sorensen, Boe S.b; Nexo, Ebbab; von der Maase, HansaAuthor Information Departments of aOncology bClinical Biochemistry, Aarhus University Hospital, DK-8000 Aarhus, Denmark Sponsorship: This study was supported by the Danish Cancer Society and ‘Radiumstationens forskningsfond’. Correspondence and requests for reprints to Henrik Schmidt, Department of Oncology, Aarhus University Hospital, Norrebrogade 44, DK-8000 Aarhus C, Denmark Tel: +45 8949 2652; fax: +45 8619 7109; e-mail: [email protected] Received 6 June 2003 Accepted 13 February 2004 Melanoma Research: June 2004 - Volume 14 - Issue 3 - p 211-215 doi: 10.1097/01.cmr.0000129378.99270.f5 Buy Metrics Abstract The aim of this study was to evaluate the biological variation in the serum level of S100β protein in untreated patients with metastatic melanoma and to use this variation to subsequently evaluate serum levels as a method of monitoring objective response to interleukin-2 (IL2) based treatment. Such an approach has not, to our knowledge, been published previously. Consecutive blood samples were collected before, during and after treatment and in the follow-up period from 66 patients treated with IL2-based immunotherapy. In 11 of these patients, a further three samples were drawn on each of 3 days prior to treatment to evaluate the variation in S100β. This variation was later used to distinguish between increased, unchanged or decreased S100β levels during treatment. We observed a significant association between changes in S100β levels and clinical outcome after the first and second treatment cycles. All responding patients had a decline in S100β levels or normal values during the first cycle. Changes in S100β levels after the first cycle and the type of treatment were independent predictive factors for the clinical outcome in multivariate analysis. In conclusion, increasing S100β values were independently associated with progressive disease, and our data suggest that significant changes in S100β levels may be valuable for monitoring and predicting clinical outcome during IL2-based immunotherapy and chemoimmunotherapy. © 2004 Lippincott Williams & Wilkins, Inc.