Sied Kebir1, Elke Hattingen1, Michael Niessen1, Laurèl Rauschenbach1, Rolf Fimmers1, Thomas Hummel1, Niklas Schäfer1, Lazaros Lazaridis1, Christoph Kleinschnitz1, Ulrich Herrlinger1, Björn Scheffler1, Martin Glas2. 1. From the Division of Clinical Neurooncology (S.K., L.L., M.G.), Department of Neurology (C.K.), West German Cancer Center (S.K., L.R., B.S., M.G.), and Department of Neurosurgery (L.R.), University Hospital Essen, University Duisburg-Essen; Division of Clinical Neurooncology, Department of Neurology and Center of Integrated Oncology (S.K., M.N., N.S., U.H., M.G.), and Institute for Medical Biometry, Informatics, and Epidemiology (R.F.), University of Bonn Medical Center; Department of Neuroradiology (E.H.), Goethe University Hospital, Frankfurt Am Main; Department of Otorhinolaryngology, Smell and Taste Clinic (T.H.), TU Dresden; DKFZ-Division Translational Neurooncology at the West German Cancer Center (S.K., B.S., M.G.), German Cancer Research Center (DKFZ), Heidelberg; and German Cancer Consortium (S.K., B.S., M.G.), Partner Site University Hospital Essen, Germany. 2. From the Division of Clinical Neurooncology (S.K., L.L., M.G.), Department of Neurology (C.K.), West German Cancer Center (S.K., L.R., B.S., M.G.), and Department of Neurosurgery (L.R.), University Hospital Essen, University Duisburg-Essen; Division of Clinical Neurooncology, Department of Neurology and Center of Integrated Oncology (S.K., M.N., N.S., U.H., M.G.), and Institute for Medical Biometry, Informatics, and Epidemiology (R.F.), University of Bonn Medical Center; Department of Neuroradiology (E.H.), Goethe University Hospital, Frankfurt Am Main; Department of Otorhinolaryngology, Smell and Taste Clinic (T.H.), TU Dresden; DKFZ-Division Translational Neurooncology at the West German Cancer Center (S.K., B.S., M.G.), German Cancer Research Center (DKFZ), Heidelberg; and German Cancer Consortium (S.K., B.S., M.G.), Partner Site University Hospital Essen, Germany. Martin.Glas@uk-essen.de.
Abstract
OBJECTIVE: To determine the role of olfactory function in patients with glioblastoma multiforme (GBM) as a prognostic clinical measure. METHODS: In a prospective case-control study, olfactory testing was performed in 73 patients with primary GBM at baseline during first-line treatment and at later follow-ups. An age-matched control cohort consisted of 49 patients with neurologic diseases, excluding those known to affect olfactory function per se. Depending on the olfactory testing score, patients were allotted to a hyposmia group (HG) or normosmia group (NG). MRI analysis was performed to assess whether tumor location affects olfactory pathways. RESULTS: Patients with GBM had olfactory dysfunction significantly more often compared to the control cohort (p = 0.003). Tumor location could not explain this finding since no relevant difference in MRI-based olfactory pathway involvement was found between HG and NG (p = 0.131). Patients with olfactory dysfunction had significantly worse overall survival (OS) and progression-free survival (PFS) compared to those without dysfunction (median OS 20.9 vs 40.6 months, p = 0.035; median PFS, 9 vs 19 months, p = 0.022). Multivariate analysis in patients without MRI-based involvement of olfactory pathways confirmed olfaction is an independent prognostic factor for OS (hazard ratio [HR] 0.43; p = 0.042) and PFS (HR 0.51; p = 0.049). CONCLUSION: This pilot study provides the first indication that olfactory dysfunction is frequently observed in GBM and may be associated with worse survival outcome in GBM. However, validation of these results in an independent cohort is needed.
OBJECTIVE: To determine the role of olfactory function in patients with glioblastoma multiforme (GBM) as a prognostic clinical measure. METHODS: In a prospective case-control study, olfactory testing was performed in 73 patients with primary GBM at baseline during first-line treatment and at later follow-ups. An age-matched control cohort consisted of 49 patients with neurologic diseases, excluding those known to affect olfactory function per se. Depending on the olfactory testing score, patients were allotted to a hyposmia group (HG) or normosmia group (NG). MRI analysis was performed to assess whether tumor location affects olfactory pathways. RESULTS:Patients with GBM had olfactory dysfunction significantly more often compared to the control cohort (p = 0.003). Tumor location could not explain this finding since no relevant difference in MRI-based olfactory pathway involvement was found between HG and NG (p = 0.131). Patients with olfactory dysfunction had significantly worse overall survival (OS) and progression-free survival (PFS) compared to those without dysfunction (median OS 20.9 vs 40.6 months, p = 0.035; median PFS, 9 vs 19 months, p = 0.022). Multivariate analysis in patients without MRI-based involvement of olfactory pathways confirmed olfaction is an independent prognostic factor for OS (hazard ratio [HR] 0.43; p = 0.042) and PFS (HR 0.51; p = 0.049). CONCLUSION: This pilot study provides the first indication that olfactory dysfunction is frequently observed in GBM and may be associated with worse survival outcome in GBM. However, validation of these results in an independent cohort is needed.