Tumour Marker: Protein S100B
Biochemistry Overview / Directory
Purpose of the test
Protein S100B is a member of a family of calcium binding proteins. S100B is present in astrocytes and glial cells in the brain and also in melanocytes. Protein S100B is currently being used in monitoring patients with malignant melanoma. Whilst the diagnosis of melanoma uses a combination of clinical and histological features, detection of metastases can be more difficult. A value greater than 0.2 µ/L is indicative of advanced disease (Stages 3 and 4) with a Positive Predictive Value of approximately 90%. Rising values can be seen 1-2 months in advance of clinical features of metastatic disease. The plasma concentration of S100B has been shown to be related to tumour burden and gives an early indication of successful response to chemotherapy. Values that fail to fall after one month of chemotherapy indicate the tumour is insensitive to the particular chemotherapy regime.
S100B is also a biochemical marker of brain injury and and a number of studies have been carried out to investigate its role in assessing and monitoring of closed head injuries and stokes. A chemiluminescent method on the Liaison analyser (DiaSorin) is used.
Reference Range
The normal range for serum S100B is less than 0.2 µg/L.
Sample Requirements
Serum (250 µL). Should be separated from red cells within 2-4 hours.
Storage and Transport
Stable at 4°C for up to two days. Send by overnight first class post.
Turnaround Time
The assay is carried out weekly.
Price
Price available on application - please contact adrianturner1@nhs.net. Discounts could be available for significant workloads.
Contacts
Ms Hagosa Abraha Tel: 020 3299 4134 e-mail: h.abraha@nhs.net
or
Ms Audrey Duffy Tel: 020 3299 4133 e-mail: audreyduffy@nhs.net
References
Townend T, Dibble C, Abid K, Vail A, Sherwood RA, Lecky F (2006). Rapid elimination of protein S100B from serum after minor head trauma. J Neurotrauma 2: 149-155
Acland K, Evans AV, Abraha HD, Healy CMJ, Roblin P, Caljonje E, Orchard G, Higgins E, Sherwood RA, Russell-Jones R. (2002) Serum S100 concentrations are not useful in predicting micrometastatic disease in malignant melanoma. Br J Derm 146: 832-5
Mohammed MQ, Abraha HD, Sherwood RA, MacRae K, Retsas S (2001) Serum S100? Protein as a Marker of Disease Activity in Patients with Malignant Melanoma. Medical Oncology 18: 109-20
