Data from Clinical Relevance of <i>KRAS</i>-Mutated Subclones Detected with Picodroplet Digital PCR in Advanced Colorectal Cancer Treated with Anti-EGFR Therapy Article Swipe
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· 2023
· Open Access
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· DOI: https://doi.org/10.1158/1078-0432.c.6524613.v1
· OA: W4361953839
<div>Abstract<p><b>Purpose:</b><i>KRAS</i> mutations are predictive of nonresponse to anti-EGFR therapies in metastatic colorectal cancer (mCRC). However, only 50% of nonmutated patients benefit from them. <i>KRAS</i>-mutated subclonal populations nondetectable by conventional methods have been suggested as the cause of early progression. Molecular analysis technology with high sensitivity and precision is required to test this hypothesis.</p><p><b>Experimental Design:</b> From two cohorts of patients with mCRC, 136 <i>KRAS</i>, <i>NRAS</i>, and <i>BRAF</i> wild-type tumors with sufficient tumor material to perform highly sensitive picodroplet digital PCR (dPCR) and 41 <i>KRAS</i>-mutated tumors were selected. All these patients were treated by anti-EGFR therapy. dPCR was used for <i>KRAS</i> or <i>BRAF</i> mutation screening and compared with qPCR. Progression-free survival (PFS) and overall survival (OS) were analyzed according to the <i>KRAS</i>-mutated allele fraction.</p><p><b>Results:</b> In addition to the confirmation of the 41 patients with <i>KRAS</i>-mutated tumors, dPCR also identified <i>KRAS</i> mutations in 22 samples considered as <i>KRAS</i> wild-type by qPCR. The fraction of <i>KRAS</i>-mutated allele quantified by dPCR was inversely correlated with anti-EGFR therapy response rate (<i>P</i> < 0.001). In a Cox model, the fraction of <i>KRAS</i>-mutated allele was associated with worse PFS and OS. Patients with less than 1% of mutant <i>KRAS</i> allele have similar PFS and OS than those with wild-type <i>KRAS</i> tumors.</p><p><b>Conclusions:</b> This study suggests that patients with mCRC with <i>KRAS</i>-mutated subclones (at least those with a <i>KRAS</i>-mutated subclones fraction lower or equal to 1%) had a benefit from anti-EGFR therapies. <i>Clin Cancer Res; 21(5); 1087–97. ©2014 AACR</i>.</p></div>