KRAS/NRAS Mutations in mCRC

Marc Peeters, MD, PhD, department of oncology, Antwerp University Hospital, Antwerpen, Belgium, discusses an analysis of RAS mutations in the phase III study 20050181, which compared panitumumab plus FOLFIRI versus FOLFIRI for second-line treatment of metastatic colorectal cancer (mCRC).

Clinical Pearls:

• In an analysis of the phase III study 20050181, researchers first looked for the wild-type patients inKRASexon 2 and then looked at the exon 3 and exon 4 in theKRASgenes andNRASgenes
• The analysis showed an additional 18% of new mutations outside theKRASexon 2 gene
• Further analysis showed that if a patient has a mutated tumor, there is no benefit but there is also no harm when a patient is treated with panitumumab plus FOLFIRI
• If patients have a wild-typeRAStumor, the analysis showed that there is a clear benefit in progression-free survival and overall survival when panitumumab is combined with FOLFIRI