Biomarker testing and mutation prevalence in metastatic colorectal cancer patients in five European countries using a large oncology database

KRAS, NRAS, BRAF, HER2 and MSI Status in a Large Consecutive Series of Colorectal Carcinomas

This study aimed to analyze clinical and regional factors influencing the distribution of actionable genetic alterations in a large consecutive series of colorectal carcinomas (CRCs). KRAS, NRAS and BRAF mutations, HER2 amplification and overexpression, and microsatellite instability (MSI) were tested in 8355 CRC samples. KRAS mutations were detected in 4137/8355 (49.5%) CRCs, with 3913 belonging to 10 common substitutions affecting codons 12/13/61/146, 174 being represented by 21 rare hot-spot variants, and 35 located outside the "hot" codons. KRAS Q61K substitution, which leads to the aberrant splicing of the gene, was accompanied by the second function-rescuing mutation in all 19 tumors analyzed. NRAS mutations were detected in 389/8355 (4.7%) CRCs (379 hot-spot and 10 non-hot-spot substitutions). BRAF mutations were identified in 556/8355 (6.7%) CRCs (codon 600: 510; codons 594-596: 38; codons 597-602: 8). The frequency of HER2 activation and MSI was 99/8008 (1.2%) and 432/8355 (5.2%), respectively. Some of the above events demonstrated differences in distribution according to patients' age and gender. In contrast to other genetic alterations, BRAF mutation frequencies were subject to geographic variation, with a relatively low incidence in areas with an apparently warmer climate (83/1726 (4.8%) in Southern Russia and North Caucasus vs. 473/6629 (7.1%) in other regions of Russia, p = 0.0007). The simultaneous presence of two drug targets, BRAF mutation and MSI, was observed in 117/8355 cases (1.4%). Combined alterations of two driver genes were detected in 28/8355 (0.3%) tumors (KRAS/NRAS: 8; KRAS/BRAF: 4; KRAS/HER2: 12; NRAS/HER2: 4). This study demonstrates that a substantial portion of RAS alterations is represented by atypical mutations, KRAS Q61K substitution is always accompanied by the second gene-rescuing mutation, BRAF mutation frequency is a subject to geographical variations, and a small fraction of CRCs has simultaneous alterations in more than one driver gene.

Receipt of Targeted Therapy and Survival Outcomes in Patients With Metastatic Colorectal Cancer

IMPORTANCE

Professional society guidelines recommend treating patients with metastatic colorectal cancer with targeted therapies, including epithelial growth factor receptor (EGFR) inhibitors and vascular endothelial growth factor (VEGF) inhibitors, depending on the presence or absence of certain mutations. Since most studies of first-line targeted therapies have been limited by sample size, there is a need for larger studies using data from routine clinical care.

OBJECTIVES

To identify factors associated with receipt of first-line targeted therapies among patients with metastatic colorectal cancer for whom RAS or BRAF mutation data in the tumor were available and investigate whether targeted therapy is associated with survival.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used deidentified data from an electronic health record-derived database to include patients from 800 sites of patient care across the US who were diagnosed with de novo metastatic colorectal cancer between January 1, 2013, and March 31, 2020 (n = 9134).

MAIN OUTCOMES AND MEASURES

Receipt of first-line targeted therapy, categorized as ever having received EGFR inhibitors, VEGF inhibitors, or neither. The secondary outcome was overall survival.

RESULTS

The study population included 9134 patients. The median age at diagnosis was 62 years (IQR, 53-71 years), 5019 (54.9%) were male, and 5692 (62.3%) were White. The median follow-up period was 15 months. Overall, 713 patients (7.8%) received EGFR inhibitors and 5081 patients (55.6%) received VEGF inhibitors as part of their first-line treatment. Among patients with RAS wild-type (RAS-WT) tumors, 625 patients (15.5%) received EGFR inhibitors and 2053 patients (50.9%) received VEGF inhibitors. In patients with RAS mutant (RAS-Mut) tumors, 50 patients (1.1%) received EGFR inhibitors and 2682 patients (59.7%) received VEGF inhibitors; among those with BRAF-mutant (BRAF-Mut) tumors, 38 patients (6.3%) received EGFR inhibitors and 346 patients (57.2%) received VEGF inhibitors. More than one-third of the patients (36.6%) received neither EGFR inhibitors nor VEGF inhibitors. Compared with patients younger than age 40 years, those aged 80 years or older had significantly lower odds to receive targeted therapies (EGFR or VEGF inhibitors in patients with RAS-WT tumors: adjusted odds ratio [aOR], 0.53; 95% CI, 0.36-0.79; and VEGF inhibitors in patients with RAS-Mut tumors: aOR, 0.62; 95% CI, 0.42-0.90). Improved survival was associated with EGFR inhibitor therapy in patients with RAS-WT tumors (adjusted hazard ratio [aHR], 0.85; 95% CI, 0.74-0.98). Unlike in clinical trials, however, no survival benefit was noted with use of VEGF inhibitors among patients with RAS-WT (aHR, 1.00; 95% CI, 0.91-1.11) or RAS-Mut (aHR, 1.01; 95% CI, 0.93-1.10) tumors.

CONCLUSIONS AND RELEVANCE

The findings of this study showed mixed results on survival benefits associated with targeted therapy. In addition, given that some of the results differed from those of randomized clinical trials, this study highlights the importance of using data originating from routine clinical care.

The cost-effectiveness analysis of serplulimab versus regorafenib for treating previously treated unresectable or metastatic microsatellite instability-high or deficient mismatch repair colorectal cancer in China

Objective

The aim of this study was to investigate the cost-effectiveness of serplulimab versus regorafenib in previously treated unresectable or metastatic microsatellite instability-high (MSI-H)/deficient mismatch repair (dMMR) colorectal cancer in China.

Methods

From the perspective of China's health-care system, a Markov model with three health states (progression free, progression, death) was developed for estimating the costs and health outcomes of serplulimab and regorafenib. Data for unanchored matching-adjusted indirect comparison (MAIC), standard parametric survival analysis, the mixed cure model, and transition probabilities calculation were obtained from clinical trials (ASTRUM-010 and CONCUR). Health-care resource utilization and costs were derived from government-published data and expert interviews. Utilities used to calculate quality-adjusted life years (QALYs) were obtained from clinical trials and literature reviews. The primary outcome was the incremental cost-effectiveness ratio (ICER) expressed as cost/QALY gained. Four scenarios were considered in scenario analysis: (a) using original survival data without conducting MAIC; (b) limiting the time horizon to the follow-up time of the clinical trial of serplulimab; (c) adopting a fourfold increase in the risk of death; and (d) applying utilities from two other sources. One-way sensitivity analysis and probabilistic sensitivity analysis were also performed to assess the uncertainty of the results.

Results

In the base-case analysis, serplulimab provided 6.00 QALYs at a cost of $68,722, whereas regorafenib provided 0.69 QALYs at a cost of $40,106. Compared with that for treatment with regorafenib, the ICER for treatment with serplulimab was $5,386/QALY, which was significantly lower than the triple GDP per capita of China in 2021 ($30,036), which was the threshold used to define the cost-effectiveness. In the scenario analysis, the ICERs were $6,369/QALY, $20,613/QALY, $6,037/QALY, $4,783/QALY, and $6,167/QALY, respectively. In the probabilistic sensitivity analysis, the probability of serplulimab being cost-effective was 100% at the threshold of $30,036/QALY.

Conclusion

Compared with regorafenib, serplulimab is a cost-effective treatment for patients with previously treated unresectable or metastatic MSI-H/dMMR colorectal cancer in China.

Diagnostic and prognostic biomarkers in colorectal cancer and the potential role of exosomes in drug delivery

Colorectal cancer (CRC) is third most common cancer with second most common cause of death worldwide. One fourth to one fifth of the CRC cases are detected at advance stage. Early detection of colorectal cancer might help in decreasing mortality and morbidity worldwide. CRC being a heterogeneous disease, new non-invasive approaches are needed to complement and improve the screening and management of CRC. Reliable and early detectable biomarkers would improve diagnosis, prognosis, therapeutic responses, and will enable the prediction of drug response and recurrence risk. Over the past decades molecular research has demonstrated the potentials of CTCs, ctDNAs, circulating mRNA, ncRNAs, and exosomes as tumor biomarkers. Non-invasive screening approaches using fecal samples for identification of altered gut microbes in CRC is also gaining attention. Exosomes can be potential candidates that can be employed in the drug delivery system. Further, the integration of in vitro, in vivo and in silico models that involve CRC biomarkers will help to understand the interactions occurring at the cellular level. This review summarizes recent update on CRC biomarkers and their application along with the nanoparticles followed by the application of organoid culture in CRC.

Impact of biomarkers and primary tumor location on the metastatic colorectal cancer first-line treatment landscape in five European countries

Background: Advances in therapies for patients with metastatic colorectal cancer (mCRC) and improved understanding of prognostic and predictive factors have impacted treatment decisions. Materials & methods: This study used a large oncology database to investigate patterns of monoclonal antibody (mAb) plus chemotherapy treatment in France, Germany, Italy, Spain and the UK in mCRC patients treated in first line in 2018. Results: Anti-EGFR mAbs were most often administered to patients with RAS wild-type mCRC and those with left-sided tumors, while anti-VEGF mAbs were preferred in RAS mutant and right-sided tumors. Adopted treatment strategies differed between countries, largely due to reimbursement. Conclusion: Biomarker status and primary tumor location steered treatment decisions in first line. Adopted treatment strategies differed between participating countries.