Aim: To evaluate whether PCR-reverse sequence-specific oligonucleotide can examine the concordance between liquid biopsy and metastatic lesions with acquired resistance.
Materials & methods: We examined acquired mutations in chemoresistant lesions and blood obtained from four patients with RAS wild-type metastatic colorectal cancer who underwent treatment with anti-epidermal growth factor receptor antibodies.
Results: In one patient, metastatic lesions harbored diverse acquired mutations in KRAS in all seven metastases; the two acquired mutations were detectable in blood collected after the patient acquired resistance. None of the other patients exhibited liquid biopsy mutations, except one, with a BRAF mutation confirmed in primary tumor and peritoneal dissemination.
Conclusion: Liquid biopsy based on PCR-reverse sequence-specific oligonucleotide is a successful procedure for capturing acquired mutations with precise information on the RAS mutational spectrum.
Keywords: Acquired mutations; BRAF; PCR-rSSO; RAS; colorectal cancer; liquid biopsy.
© 2021 The Authors.