Unknown

Dataset Information

0

RAS and BRAF mutations in cell-free DNA are predictive for outcome of cetuximab monotherapy in patients with tissue-tested RAS wild-type advanced colorectal cancer.


ABSTRACT: In metastatic colorectal cancer, RAS and BRAF mutations cause resistance to anti-EGFR therapies, such as cetuximab. Heterogeneity in RAS and BRAF mutations might explain nonresponse in a subset of patients receiving cetuximab. Analyzing mutations in plasma-derived circulating tumor DNA (ctDNA) could provide a more comprehensive overview of the mutational landscape as compared to analyses of primary and/or metastatic tumor tissue. Therefore, this prospective multicenter study followed 34 patients with metastatic colorectal cancer who were tissue-tested as RAS wild-type (exons 2-4) during routine work-up and received third-line cetuximab monotherapy. BRAF mutation status was also tested but did not exclude patients from therapy. At baseline and upon disease progression, cell-free DNA (cfDNA) was isolated for targeted next-generation sequencing (NGS). At 8 weeks, we determined that patients had benefited from treatment. NGS of cfDNA identified three patients with RAS mutations not detected in tumor tissue during routine work-up. Another six patients had a BRAF or rare RAS mutation in ctDNA and/or tumor tissue. Relative to patients without mutations in RAS/BRAF, patients with mutations at baseline had shorter progression-free survival [1.8 versus 4.9 months (P < 0.001)] and overall survival [3.1 versus 9.4 months (P = 0.001)]. In patients with clinical benefit (progressive disease after 8 weeks), ctDNA testing revealed previously undetected mutations in RAS/BRAF (71%) and EGFR (47%), which often emerged polyclonally. Our results indicate that baseline NGS of ctDNA can identify additional RAS mutation carriers, which could improve patient selection for anti-EGFR therapies. Acquired resistance, in patients with initial treatment benefit, is mainly explained by polyclonal emergence of RAS, BRAF, and EGFR mutations in ctDNA.

SUBMITTER: van Helden EJ 

PROVIDER: S-EPMC6822250 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature

altmetric image

Publications

RAS and BRAF mutations in cell-free DNA are predictive for outcome of cetuximab monotherapy in patients with tissue-tested RAS wild-type advanced colorectal cancer.

van Helden Erik J EJ   Angus Lindsay L   Menke-van der Houven van Oordt C Willemien CW   Heideman Daniëlle A M DAM   Boon Eline E   van Es Suzanne C SC   Radema Sandra A SA   van Herpen Carla M L CML   de Groot Derk Jan A DJA   de Vries Elisabeth G E EGE   Jansen Maurice P H M MPHM   Sleijfer Stefan S   Verheul Henk M W HMW  

Molecular oncology 20190930 11


In metastatic colorectal cancer, RAS and BRAF mutations cause resistance to anti-EGFR therapies, such as cetuximab. Heterogeneity in RAS and BRAF mutations might explain nonresponse in a subset of patients receiving cetuximab. Analyzing mutations in plasma-derived circulating tumor DNA (ctDNA) could provide a more comprehensive overview of the mutational landscape as compared to analyses of primary and/or metastatic tumor tissue. Therefore, this prospective multicenter study followed 34 patients  ...[more]

Similar Datasets

| S-EPMC7076055 | biostudies-literature
| S-EPMC7645532 | biostudies-literature
| S-EPMC7914886 | biostudies-literature
2008-01-31 | GSE5851 | GEO
| S-EPMC5885260 | biostudies-literature
| S-EPMC9272566 | biostudies-literature
| S-EPMC5348362 | biostudies-literature
| S-EPMC7794191 | biostudies-literature
| S-EPMC7785657 | biostudies-literature
| S-EPMC3235081 | biostudies-literature