scholarly journals Genomic temporal heterogeneity of circulating tumour DNA in unresectable metastatic colorectal cancer under first-line treatment

Gut ◽  
2021 ◽  
pp. gutjnl-2021-324852
Author(s):  
Feng Wang ◽  
You-Sheng Huang ◽  
Hao-Xiang Wu ◽  
Zi-Xian Wang ◽  
Ying Jin ◽  
...  

ObjectiveCirculating tumour DNA (ctDNA) sequencing is increasingly used in the clinical management of patients with colorectal cancer. However, the genomic heterogeneity in ctDNA during treatments and its impact on clinical outcomes remain largely unknown.DesignWe conducted a prospective cohort study (NCT04228614) of 171 patients with unresectable metastatic colorectal cancer (mCRC) who underwent first-line treatment and prospectively collected blood samples with or without tumour samples from patients at baseline and sequentially until disease progression or last follow-up.ResultsThe RAS/BRAF alterations in paired baseline tissue and plasma samples from 63 patients displayed a favourable concordance (81.0%, 51/63). After a period of first-line treatment (median time between baseline and last liquid biopsy, 4.67 months), 42.6% (26/61) of RAS-mutant patients showed RAS clearance and 50.0% (5/10) of BRAF-mutant patients showed BRAF clearance, while 3.6% (3/84) and 0.7% (1/135) of patients showed new RAS or BRAF mutations in ctDNA. Patients with plasma RAS/BRAF clearance showed similar progression-free survival (PFS) and overall survival (OS) with patients who remained RAS/BRAF wild-type, while much better outcomes than those who remained RAS/BRAF mutant. Patients who gained new RAS/BRAF mutations showed similar prognosis as those who maintained RAS/BRAF mutations, and shorter PFS and OS than those who remained RAS/BRAF wild-type.ConclusionThis prospective, serial and large-scale ctDNA profiling study reveals the temporal heterogeneity of mCRC-related somatic variants, which should be given special attention in clinical practice, as evidenced by the finding that the shift in plasma RAS/BRAF mutational status can yield a drastic change in survival outcomes.

2021 ◽  
Vol 22 (14) ◽  
pp. 7717
Author(s):  
Guido Giordano ◽  
Pietro Parcesepe ◽  
Giuseppina Bruno ◽  
Annamaria Piscazzi ◽  
Vincenzo Lizzi ◽  
...  

Target-oriented agents improve metastatic colorectal cancer (mCRC) survival in combination with chemotherapy. However, the majority of patients experience disease progression after first-line treatment and are eligible for second-line approaches. In such a context, antiangiogenic and anti-Epidermal Growth Factor Receptor (EGFR) agents as well as immune checkpoint inhibitors have been approved as second-line options, and RAS and BRAF mutations and microsatellite status represent the molecular drivers that guide therapeutic choices. Patients harboring K- and N-RAS mutations are not eligible for anti-EGFR treatments, and bevacizumab is the only antiangiogenic agent that improves survival in combination with chemotherapy in first-line, regardless of RAS mutational status. Thus, the choice of an appropriate therapy after the progression to a bevacizumab or an EGFR-based first-line treatment should be evaluated according to the patient and disease characteristics and treatment aims. The continuation of bevacizumab beyond progression or its substitution with another anti-angiogenic agents has been shown to increase survival, whereas anti-EGFR monoclonals represent an option in RAS wild-type patients. In addition, specific molecular subgroups, such as BRAF-mutated and Microsatellite Instability-High (MSI-H) mCRCs represent aggressive malignancies that are poorly responsive to standard therapies and deserve targeted approaches. This review provides a critical overview about the state of the art in mCRC second-line treatment and discusses sequential strategies according to key molecular biomarkers.


2021 ◽  
Vol 39 (3_suppl) ◽  
pp. 86-86
Author(s):  
Takanori Watanabe ◽  
Akihito Tsuji ◽  
Manabu Shiozawa ◽  
Hirofumi Ota ◽  
Hironaga Satake ◽  
...  

86 Background: Triplet regimens, FOLFOXIRI, combined with bevacizumab (bev) or panitumumab have been shown to be superior in terms of early tumor shrinkage (ETS) and depth of response (DpR) compared to doublet regimen plus bev or triplet regimen in patients with RAS wild-type metastatic colorectal cancer (mCRC), in the TRIBE trial ( N Engl J Med 2014) or VOLFI trial ( J Clin Oncol 2019), respectively. There have been few studies which directly compared cetuximab (cet) with bev when combined with triplet regimen. Therefore, we investigated the efficacy and safety of bev vs. cet in combination with FOLFOXIRI in previously untreated mCRC patients with RAS wild-type tumors. Methods: This trial was a randomized phase II trial to evaluate modified (m)-FOLFOXIRI (irinotecan 150 mg/m2, oxaliplatin 85 mg/m2, 5-FU 2400 mg/m2) plus cet vs. bev as first-line treatment in terms of the DpR during the entire course as the primary endpoint in 360 patients with RAS wild-type mCRC (ClinicalTrials.gov Identifier: NCT02515734). The experimental arm with cet was considered to be active if the difference of median DpR was over 12.5% compared with the bev arm, under the conditions of significance level of 0.05 and power of 0.85. Secondary endpoints included the ETS at week 8, progression-free survival, overall survival, secondary resection rate, and toxicity. Results: A total of 359 patients were enrolled between July 2015 and June 2019. For the safety analysis set (median age 65y, 64% male, PS0/1:91%/9%, left/right primary:83%/17%), 173 and 175 patients were randomly assigned to the cet and bev arms, respectively, some patients were excluded for the safety analysis due to the violation of inclusion criteria (6 for cet arm and 5 for bev). On the cutoff date of September 2020, median number of cycles administered was 10 (range, 1-51) for the cet arm and 12 (range, 1-51) for the bev arm. The incidence of severe adverse events (AEs) was 25.4% (44/173) for the cet arm and 25.7% (45/175) for the bev arm, respectively. The following AEs of grade 3-4 were observed more frequently in the cet arm compared to the bev arm: oral mucositis (9.2% vs. 2.3%), diarrhea (12.1% vs. 8.0%), dermatitis acneiform (12.1% vs. 0%), and hypomagnesemia (4.0% vs. 0%). The treatment-related death occurred in 2 patients of the cet arm, while no patients in the bev arm. The rate of treatment discontinuation due to AEs of any cause was comparable between the cet and bev arms (7% vs. 9%). Conclusions: This safety analysis indicated that both regimens of m-FOLFOXIRI plus cet or bev were tolerable in RAS wt mCRC patients although some frequent severe AEs were observed. Clinical trial information: UMIN000018217.


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