Abstract A032: Circulating tumor (ct)DNA mutations inEGFRpathway genes and clinical outcomes for patients with metastatic colorectal cancer (mCRC) treated with panitumumab from the ASPECCT study

Author(s):  
Michael Boedigheimer ◽  
Agnes Lee Ang ◽  
Tae Won Kim ◽  
Anne Thomas ◽  
Peter Gibbs ◽  
...  
Diagnostics ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 502
Author(s):  
Virgílio Souza e Silva ◽  
Emne Ali Abdallah ◽  
Angelo Borsarelli Carvalho de Brito ◽  
Alexcia Camila Braun ◽  
Milena Shizue Tariki ◽  
...  

The discovery of predictive biomarkers in metastatic colorectal cancer (mCRC) is essential to improve clinical outcomes. Recent data suggest a potential role of circulating tumor cells (CTCs) as prognostic indicators. We conducted a follow-on analysis from a prospective study of consecutive patients with mCRC. CTC analysis was conducted at two timepoints: baseline (CTC1; before starting chemotherapy), and two months after starting treatment (CTC2). CTC isolation/quantification were completed by ISET® (Rarecells, France). CTC expressions of drug resistance-associated proteins were evaluated. Progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan–Meier method. Seventy-five patients were enrolled from May 2012 to May 2014. A CTC1 cut-off of >1.5 CTCs/mL was associated with an inferior median OS compared to lower values. A difference of CTC2−CTC1 > 5.5 CTCs/mL was associated with a reduced median PFS. By multivariate analysis, CTC1 > 1.5 CTCs/mL was an independent prognostic factor for worse OS. Multi-drug resistance protein-1 (MRP-1) expression was associated with poor median OS. CTC baseline counts, kinetics, and MRP-1 expression were predictive of clinical outcomes. Larger studies are warranted to explore the potential clinical benefit of treating mCRC patients with targeted therapeutic regimens guided by CTC findings.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3577-3577
Author(s):  
Stefano Mariani ◽  
Marco Puzzoni ◽  
Nicole Liscia ◽  
Valentino Impera ◽  
Andrea Pretta ◽  
...  

3577 Background: The rechallenge with EGFR inhibitors represents an emerging strategy for anti-EGFR pre-treated patients with RAS wild type colorectal cancer (CRC). Unfortunately definitive selection criteria for anti-EGFR rechallenge in this setting are lacking. Very recently RAS wild type status on circulating tumor DNA (ct-DNA) at the time of rechallenge along with already known clinical criteria emerged as a potential watershed for this strategy. In the present study we explored liquid biopsy-driven anti-EGFR rechallenge strategy in the clinical practice for patients with metastatic colorectal cancer. Methods: Ct-DNA from RAS and BRAF wild type metastatic CRC patients previously treated with an anti-EGFR containing therapy was analyzed for RAS/BRAF mutations with the aim to evaluate the rechallenge strategy with anti-EGFR. The ct-DNA was analyzed for RAS-BRAF mutations using pyro-sequencing (PyroMark Q24 MDx Workstation) and nucleotide sequencing (Genetic Analyzer ABI3130) assays. Real-time PCR (Idylla) and droplet digital PCR (QX200 System) were performed to confirm the RAS-BRAF mutation status. Several clinical variables including previous response to anti EGFR containing therapy, tumor sidedness and anti-EGFR free interval were evaluated in relation to outcome. Tumor response evaluation was performed according to RECIST 1.1. Differences between categorical variables were evaluated using the Fisher’s exact test. Survival probability over time was estimated by the Kaplan–Meier method. Significant differences in the probability of survival between the strata were evaluated by log-rank test. Results: Twenty patients were included in the study. All patients were tested for RAS-BRAF mutations in ct-DNA. Fourteen patients (70%) showed a RAS-BRAF WT molecular profile, six patients (30%) showed a KRAS mutation. All the patients with ct-DNA RAS-BRAF WT profile underwent rechallenge with anti-EGFR. In details 11 patients (78.6%) underwent irinotecan+ cetuximab treatment, whereas 3 patients (21.4%) underwent panitumumab monotherapy. As for the outcome results to the rechallenge strategy, the median OS was 7 months (95% CI 5.0 to 13.0), the median PFS was 3 months (95% CI 2.0 to 6.0), the ORR was 27.3% with a DCR of 54.5%. Among the clinical variables evaluated as putative predictive/prognostic factors, previous response to anti-EGFR treatment was related to a not statistically significant improved OS (12 months vs 5 months HR:0.19 p: 0.06) and to a statistically significant improved ORR (75% vs 0% p:0.03). Conclusions: The rechallenge strategy with anti-EGFR confirmed to be feasible in clinical practice. The clinical outcome resulted consistent with the literature data. In addition to the molecular selection through the analysis of ct-DNA for RAS, previous response to anti EGFR treatment is confirmed as a prospective selection criteria for this therapeutic option.


Oncology ◽  
2012 ◽  
Vol 82 (2) ◽  
pp. 83-89 ◽  
Author(s):  
Seong Joon Park ◽  
Yong Sang Hong ◽  
Jae-Lyun Lee ◽  
Min-Hee Ryu ◽  
Heung Moon Chang ◽  
...  

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 3540-3540 ◽  
Author(s):  
Shota Fukuoka ◽  
Toshikazu Moriwaki ◽  
Hiroya Taniguchi ◽  
Atsuo Takashima ◽  
Yosuke Kumekawa ◽  
...  

3540 Background: It is unclear which drug of REG or TAS-102 should be used earlier for the patients with metastatic colorectal cancer (mCRC) who have access to both drugs. This study investigated the comparison of the efficacy between REG and TAS-102 in patients with refractory to standard chemotherapies. Methods: The clinical data of patients who were treated with REG or TAS-102 among these drugs naive mCRC patients between Jun 2014 and Sep 2015 were retrospectively delivered from 24 institutions of Japanese Society for Cancer of the Colon and Rectum (JSCCR). The primary endpoint was overall survival (OS). Propensity score (PS) was calculated with a logistic regression, in which using baseline parameters were included. Two methods, adjusted and matched analysis, to take propensity score were used. The clinical outcomes were evaluated with Kaplan-Meier method and Cox models based on PS adjustment and matching. Results: Total of 589 patients were enrolled and 550 patients (223 patients in the REG group and 327 patients in the TAS-102 group) met criteria for inclusion in the analysis. The results from PS adjusted analyses showed that OS was similar between the two groups (HR of TAS-102 to REG, 0.96; 95% confidence interval, 0.78–1.18). There were also no statistically significant differences between two groups for progression-free survival (HR 0.94) and time to ECOG Performance status≥2 (HR 1.00), expect for time to treatment failure (HR 0.81; P = 0.025). In the subgroup analysis, REG showed favorable survival compared with TAS-102 in the age of < 65 years patients and unfavorable survival in ≥65 years patients (P for interaction = 0.012). In the PS matched sample (174 patients in each group), the clinical outcomes were similar to the results of the PS adjusted analysis. Conclusions: Although REG and TAS-102 showed a similar efficacy in mCRC patients with refractory to standard chemotherapies, the choice of the drug by age might affect the survival. Supported by JSCCR. Clinical trial information: UMIN000020416


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