Clinical utility of circulating DNA analysis for rapid detection of actionable mutations to select metastatic colorectal patients for anti-EGFR treatment.

BACKGROUND: While tumor-tissue remains the 'gold standard' for genetic analysis in cancer patients, it is challenged with the advent of circulating cell-free tumor DNA (ctDNA) analysis from blood samples. Here, we broaden our previous study on the clinical validation of plasma DNA in metastatic colorectal cancer patients, by evaluating its clinical utility under standard management care. PATIENTS AND METHODS: Concordance and data turnaround-time of ctDNA when compared with tumor-tissue analysis were studied in a real-time blinded prospective multicenter clinical study (n = 140 metastatic colorectal patients). Results are presented according to STARD criteria and were discussed in regard with clinical outcomes of patients. RESULTS: Much more mutations were found by ctDNA analysis: 59%, 11.8% and 14.4% of the patients were found KRAS, NRAS and BRAF mutant by ctDNA analysis instead of 44%, 8.8% and 7.2% by tumor-tissue analysis. Median tumor-tissue data turnaround-time was 16 days while 2 days for ctDNA analysis. Discordant samples analysis revealed that use of biopsy, long delay between tumor-tissue and blood collection and resection of the tumor at time of blood draw, tumor site, or type of tissue analyzed seem to affect concordance. Altogether, the clinical data with respect to the anti-epidermal growth factor receptor response (RAS status) and the prognosis (BRAF status) of those discordant patients do not appear contradictory to the mutational status as determined by plasma analysis. Lastly, we present the first distribution profile of the RAS and BRAF hotspot mutations as determined by ctDNA analysis (n = 119), revealing a high proportion of patients with multiple mutations (45% of the population and up to 5 mutations) and only 24% of WT scored patients for both genes. Mutation profile as determined from ctDNA analysis with using various detection thresholds highlights the importance of the test sensitivity. CONCLUSION: Our study showed that ctDNA could replace tumor-tissue analysis, and also clinical utility of ctDNA analysis by considerably reducing data turnaround time.

Randomized phase II trial comparing molecularly targeted therapy based on tumor molecular profiling versus conventional therapy in patients with refractory cancer: cross-over analysis from the SHIVA trial.

Background: Several studies used the ratio of progression-free survival (PFS) on genotype-matched treatment to PFS on genotype-unmatched treatment to assess the efficacy of therapy guided by patients' tumor molecular profiling. We evaluated the PFS ratio from patients who cross-over in the SHIVA trial. Patients and methods: The primary end point of the SHIVA trial was to compare PFS on molecularly targeted agents (MTAs) based on tumor molecular profiling and treatment at physician's choice (TPC) in patients with any kind of cancer who had failed standard-of-care therapy. The experimental treatment included only marketed MTAs given outside their indications according to a pre-specified treatment algorithm. Patients were allowed to cross-over at disease progression in both arms. Response was evaluated according to RECIST 1.1 at randomization and at cross-over. We evaluated the ratio of PFS on MTA (PFSMTA) to PFS on TPC (PFSTPC) in patients who crossed-over. Results: Among 741 patients enrolled in the SHIVA trial, 197 were randomized, and 95 crossed-over, including 70 patients from the TPC to the MTA arm and 25 patients from the MTA to the TPC arm. Two patients crossed-over in the TPC arm without disease progression. The PFSMTA/PFSTPC ratio exceeded 1.3 in 37% of patients who crossed-over from the TPC to the MTA arm. The PFSMTA/PFSTPC ratio exceeded 1.3 in 61% of patients who crossed-over from the MTA arm to the TPC arm. Conclusions: The cross-over analysis of the SHIVA trial identified 37% of patients who crossed-over from TPC to MTA with a PFSMTA/PFSTPC ratio exceeding 1.3.

Randomised proof-of-concept phase II trial comparing targeted therapy based on tumour molecular profiling vs conventional therapy in patients with refractory cancer: results of the feasibility part of the SHIVA trial.

BACKGROUND: The SHIVA trial is a multicentric randomised proof-of-concept phase II trial comparing molecularly targeted therapy based on tumour molecular profiling vs conventional therapy in patients with any type of refractory cancer. RESULTS of the feasibility study on the first 100 enrolled patients are presented. METHODS: Adult patients with any type of metastatic cancer who failed standard therapy were eligible for the study. The molecular profile was performed on a mandatory biopsy, and included mutations and gene copy number alteration analyses using high-throughput technologies, as well as the determination of oestrogen, progesterone, and androgen receptors by immunohistochemistry (IHC). RESULTS: Biopsy was safely performed in 95 of the first 100 included patients. Median time between the biopsy and the therapeutic decision taken during a weekly molecular biology board was 26 days. Mutations, gene copy number alterations, and IHC analyses were successful in 63 (66%), 65 (68%), and 87 (92%) patients, respectively. A druggable molecular abnormality was present in 38 patients (40%). CONCLUSIONS: The establishment of a comprehensive tumour molecular profile was safe, feasible, and compatible with clinical practice in refractory cancer patients.