Circulating DNA as a Strong Multimarker Prognostic Tool for Metastatic Colorectal Cancer Patient Management Care

Abstract

Purpose: Circulating cell-free DNA (ccfDNA) is a valuable source of tumor material obtained from a simple blood sampling that enables noninvasive analysis of the tumor genome. Our goal was to carry out a multiparametric analysis of ccfDNA and evaluate its prognostic value by investigating the overall survival (OS) of 97 metastatic colorectal cancer patients (mCRC).Experimental Design: Qualitative parameters (determination of the main KRAS exon2 and BRAF V600E mutations) and quantitative parameters (total ccfDNA concentration, mutant ccfDNA concentration, the proportion of mutant ccfDNA, and ccfDNA integrity index) were determined simultaneously in a single run using a unique Q-PCR multimarker approach (100% success rate).Results: The median follow-up time was 36 months and median OS was 22 months. Patients showing high ccfDNA levels had significantly shorter OS (18.07 months vs. 28.5 months, P ¼ 0.0087). Moreover, multivariate analysis revealed that a high ccfDNA level is an independent prognostic factor (P ¼ 0.034). All ccfDNA parameters were of prognostic interest: patients with higher levels of mutant ccfDNA and higher mutation loads for the detected mutations had shorter OS (P ¼ 0.0089 and P ¼ 0.05, respectively). In addition, the level of ccfDNA fragmentation correlated positively with decreased OS in the exclusive KRAS/ BRAF-mutant cohort of patients (P ¼ 0.0052) and appeared as a strong independent prognostic factor (P ¼ 0.0072), whereas it was not significant in the exclusive KRAS/BRAF WT cohort of patients (P ¼ 0.67).Conclusions: Our data provide for the first time qualitative and quantitative evidence in favor of multiparametric ccfDNA analysis in mCRC patients for prognostic assessment.

Can molecular biomarkers replace a clinical risk score for resectable colorectal liver metastasis?

“…However, technological shortcomings and difficulty in finding the perfect markers to identify such CTCs or ctDNA have resulted in few studies of any clinically valuable difference in terms of survival outcomes or prediction[31]. Other studies appear promising, including one recent meta-analysis on the prognostic role of ctDNA[32], also for disease prediction but are small and need further validation[33-35]. …”

Role of circulating free DNA in colorectal cancer

“…Qualitative characteristics, such as methylated cfDNA levels have also been shown to independently predict OS in mCRC[62]. In the largest published prospective mCRC patient cohort ( n = 97), El Messaoudi et al[63] used qPCR and showed that cfDNA levels, higher specific mutation loads and the level of cfDNA fragmentation are strong prognostic factors; cfDNA levels were independent prognostic factors for the entire patient cohort and the level of fragmentation only for the KRAS/BRAF mutated subset. Specifically, a difference in OS of 10 mo was reported between the groups of high vs low cfDNA levels (18.07 mo vs 28.5 mo respectively, P = 0.0087)[63].…”

“…In the largest published prospective mCRC patient cohort ( n = 97), El Messaoudi et al[63] used qPCR and showed that cfDNA levels, higher specific mutation loads and the level of cfDNA fragmentation are strong prognostic factors; cfDNA levels were independent prognostic factors for the entire patient cohort and the level of fragmentation only for the KRAS/BRAF mutated subset. Specifically, a difference in OS of 10 mo was reported between the groups of high vs low cfDNA levels (18.07 mo vs 28.5 mo respectively, P = 0.0087)[63]. Finally, Spindler et al[64] compared the prognostic value of the detection of KRAS mutations in the plasma compared to the primary tumor with the use of qPCR, with the former being an independent predictor for OS (HR = 2.98, 95%CI: 1.53-5.80, P = 0.001) and PFS (HR = 2.84, 95%CI: 1.46-5.53, P = 0.002), whereas the latter had no correlation with outcomes, which underscores the value of cfDNA qualitative testing.…”

Evaluation of Methylation Biomarkers for Detection of Circulating Tumor DNA and Application to Colorectal Cancer

“…The detection of ctDNA can be used for obtaining diagnostic, prognostic and theranostic information concerning cancer. The diagnostic utility of ctDNA primarily stems from the presence of somatic genomic alterations, such as in the KRAS , BRAF and EGFR genes, which are absent from DNA taken from matched normal cells and in the circulating cell-free DNA (ccfDNA) of healthy subjects [1,2,3,4,5,6]. …”