KRAS mutations, which are found in 30% to 45% of all colorectal tumors, are excellent indicators of which patients will benefit from the addition of cetuximab, a drug which targets epidermal growth factor receptor (EGFR). If KRAS, a gene which is located upstream of EGFR, is mutated then patients are unlikely to respond to this drug as they will have no functional EGFR.

Testing for this particular mutation defines the predicted response to this drug. A recent study showed that combination therapy which included cetuximab reduced the risk for metastatic colorectal cancer growth or spread by 15%. KRAS mutation analysis is now therefore a standard of care necessary for all newly diagnosed CRCs.
Sample type and Volume required: 
Paraffin processed blocks or sections of tumour.

Tissue that has been decalcified in acid is not suitable.
Turnaround time: 
2 – 3 Weeks
Storage and transport: 
First class post within 4 days (temperature not to exceed 30°C during transport)
Cellular Pathology at Guy's And St Thomas' Hospital
Histology: 0207 188 7188 extension 54611 , Cytology: 0207 188 2915, Oral Pathology: 0207 188 4367
Histopathology & Cytopathology Laboratories
Cellular Pathology
St Thomas' Hospital
North Wing - 2nd Floor
Westminster Bridge Road
London SE1 7EH

Head and Neck/Oral Pathology Laboratory
4th Floor, Tower Wing
Guy's Hospital
Great Maze Pond
London SE1 9RT

For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 07/08/2015