Predictive and Prognostic Implications of Mutation Profiling and Microsatellite Instability Status in Patients with Metastatic Colorectal Carcinoma

SNP array genomic analysis of matched pairs of brain and liver metastases in primary colorectal cancer

PURPOSE

Brain metastasis formation is a rare and late event in colorectal cancer (CRC) patients and associated with poor survival. In contrast to other metastatic sites, the knowledge on chromosomal aberrations in brain metastases is very limited.

METHODS

Therefore, we carried out single nucleotide polymorphism (SNP) array analyses on matched primary CRC and brain metastases of four patients as well as on liver metastases of three patients.

RESULTS

Brain metastases showed more chromosomal aberrations than primary tumors or liver metastases. Commonly occurring aberrations were gain of 8q11.1-q24.3 (primary CRC), gain of 13q12.13-q12.3 (liver metastases), and gain of 20q11.1-q13.33 (brain metastases). Furthermore, we found one copy-neutral loss of heterozygosity (cn-LOH) region on chromosome 3 in primary CRC, three cn-LOH regions in liver metastases and 23 cn-LOH regions in brain metastases, comprising 26 previously undescribed sites.

CONCLUSION

The more frequent occurrence of cn-LOHs and subsequently affected genes in brain metastases shed light on the pathophysiology of brain metastasis formation. Further pairwise genetic analyses between primary tumors and their metastases will help to define the role of affected genes in cn-LOH regions.

European expert panel consensus on the clinical management of BRAFV600E-mutant metastatic colorectal cancer

Metastatic colorectal cancer (mCRC) is a heterogenous disease caused by various genetic alterations. The BRAF^V600E mutation occurs in approximately 8-12% of patients and is characterised by an aggressive clinical course and poor prognosis. Here we review the current knowledge on BRAF^V600E-mutant mCRC and provide a series of consensus statements on its clinical management. The treatment landscape for BRAF^V600E-mutant mCRC has changed greatly due to the emergence of molecular targeted therapies (including BRAF inhibitors) and immune checkpoint inhibitors. A scientific literature search identified available data on molecular testing, treatments, and clinical monitoring of patients with BRAF^V600E-mutant mCRC. Consensus statements were discussed and developed by a European expert panel. This manuscript provides consensus management guidance for different clinical presentations of BRAF^V600E-mutant mCRC and makes recommendations regarding treatment sequencing choices. To guide appropriate clinical management and treatment decisions for mCRC patients, tumour tissue analysis for DNA mismatch repair/microsatellite status and, at a minimum, KRAS, NRAS, and BRAF mutational status is mandatory at the time of diagnosis. Finally, we discuss the rapidly evolving treatment landscape for BRAF^V600E-mutant mCRC and define priorities for the development of novel therapeutic strategies that are needed to improve patient outcomes.

Predictive preoperative clinical score for patients with liver-only oligometastatic colorectal cancer

Background

Resection of liver metastases from colorectal cancer (CRC) in the oligometastatic stage improves survival and is a potentially curative treatment. Thus, predictive scores that reliably identify those patients who especially benefit from surgery are essential.

Patients and methods

In this multicenter analysis, 512 patients had undergone surgery for liver metastases from CRC. We investigated distinct cancer-specific risk factors that are routinely available in clinical practice and developed a predictive preoperative score using a training cohort (TC), which was thereafter tested in a validation cohort (VC).

Results

Inflammatory response to the tumor, a right-sided primary tumor, multiple liver metastases, and node-positive primary tumor were significant adverse variables for overall survival (OS). Patients were stratified in five groups according to the cumulative score given by the presence of these risk factors. Median OS for patients without risk factors was 133.8 months [95% confidence interval (CI) 81.2-not reached (nr)] in the TC and was not reached in the VC. OS decreased significantly for each subsequent group with increasing number of risk factors. Median OS was significantly shorter (P < 0.0001) for patients presenting all four risk factors: 14.3 months (95% CI 10.5 months-nr) in the TC and 16.6 months (95% CI 14.6 months-nr) in the VC.

Conclusions

Including easily obtainable variables, this preoperative score identifies oligometastatic CRC patients with prolonged survival rates that may be cured, and harbors potential to be implemented in daily clinical practice.

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We identified four variables of adverse outcome for patients treated with surgical resection of liver metastases from CRC.

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Adverse variables were inflammatory response to the tumor, multiple metastases, right-sided primary tumor, node-positive primary tumor.

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We developed a preoperative clinical score according to the number of risk factors present.

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Using easily obtainable variables, this score identified patients with oligometastatic CRC with good prognosis.

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Patients without risk factors should strongly be considered for surgical resection of their metastases.

Pulmonary metastasectomy in colorectal carcinoma

Colorectal cancer (CRC) is one of the leading causes of cancer-related deaths worldwide. It is estimated that 50% of all patients with CRC develop metastases, most commonly in the liver and the lung. Lung metastases are seen in approximately 10–15% of all patients with CRC. A large number of these patients with metastatic CRC can only receive palliative treatment due to invasion of other organs and disseminated disease. However, a subset of these patients present with potentially resectable metastases. Pulmonary metastasectomy is considered to be a potentially curative treatment for selected patients with resectable metastatic CRC. Current data suggest that patients that undergo pulmonary metastasectomy have 5-year survival rates of approximately 40%. However, the majority of data published regarding lung metastasectomy is based on small, retrospective case series. Due to this lack of prospective data, it is still unclear which subset of patients will benefit most from curative-intent surgery. Furthermore, there is also controversy regarding which prognostic and genetic factors are related to survival outcomes and whether there is a difference between open and thoracoscopic approaches in terms of overall and disease-free survival. In this review, we aim to summarize the latest data on prognostic factors and survival outcomes after pulmonary metastasectomy in patients with metastatic CRC.

Brain Metastases from Colorectal Cancer: A Systematic Review of the Literature and Meta-Analysis to Establish a Guideline for Daily Treatment

Colorectal cancer (CRC) is the third most common malignancy worldwide. Most patients with metastatic CRC develop liver or lung metastases, while a minority suffer from brain metastases. There is little information available regarding the presentation, treatment, and overall survival of brain metastases (BM) from CRC. This systematic review and meta-analysis includes data collected from three major databases (PubMed, Cochrane, and Embase) based on the key words "brain", "metastas*", "tumor", "colorectal", "cancer", and "malignancy". In total, 1318 articles were identified in the search and 86 studies matched the inclusion criteria. The incidence of BM varied between 0.1% and 11.5%. Most patients developed metastases at other sites prior to developing BM. Lung metastases and KRAS mutations were described as risk factors for additional BM. Patients with BM suffered from various symptoms, but up to 96.8% of BM patients were asymptomatic at the time of BM diagnosis. Median survival time ranged from 2 to 9.6 months, and overall survival (OS) increased up to 41.1 months in patients on a multimodal therapy regimen. Several factors including age, blood levels of carcinoembryonic antigen (CEA), multiple metastases sites, number of brain lesions, and presence of the KRAS mutation were predictors of OS. For BM diagnosis, MRI was considered to be state of the art. Treatment consisted of a combination of surgery, radiation, or systemic treatment.

KRAS Codon 12 Mutation is Associated with More Aggressive Invasiveness in Synchronous Metastatic Colorectal Cancer (mCRC): Retrospective Research

Objective

To investigate the connection between mutant KRAS/NRAS/BRAF and clinicopathological characteristics in therapy-naïve synchronous metastatic colorectal cancer (mCRC) in Chinese populations when compared with all wild type (KRAS/NRAS/BRAF wild type).

Patients and Methods

A total of 200 patients with therapy-naïve synchronous mCRC (TNM stage: TanyNanyM1) were retrospectively collected as study objects. Primary tumor tissues from 200 mCRC patients were analyzed through next-generation sequencing panel to assess the mutated regions of KRAS/NRAS/BRAF.

Results

The distribution frequency of gene mutation in our study was 41% KRAS, 4% NRAS, 11.5% BRAF, 0.5% both KRAS and BRAF. Tumors with any gene mutations (any gene mutations in KRAS/NRAS/BRAF), KRAS and KRAS codon 12 mutation were more likely to be located in right-sided colon (P=0.007, P=0.008, P=0.026, respectively). For metastasis, tumors with any gene mutations, KRAS and KRAS codon 12 mutation were significantly correlated with peritoneal metastasis (P=0.019, P=0.017, P=0.014, respectively), liver-peritoneum metastases (P=0.004, P=0.003, P=0.002, respectively) and multi-organ metastases (P=0.002, P=0.008, P=0.001, respectively). Tumors with all wild type were significantly correlated with distant lymph node-only metastasis. No statistically significant differences were found between clinicopathological characteristics and KRAS codon 13 and NRAS mutations.

Conclusion

Our study suggests that clinicopathological characteristics (specifically for metastasis) are related to KRAS/NRAS/BRAF mutations in therapy-naïve synchronous mCRC population in China. We demonstrated that distant lymph node-only metastasis is visibly linked to all wild-type tumors. We found that patients with any gene mutations, KRAS mutation are more likely to carry peritoneal metastasis, liver-peritoneum metastases and multi-organ metastases than those with all wild type. After stratification, KRAS codon 12 mutation, but not codon 13 mutation, was remarkably associated with peritoneal metastasis, liver-peritoneum metastases, and multi-organ metastases compared to all wild type. These results may be useful for aiding in the prediction of prognosis and choosing the appropriate regimens for therapy.

HER2 and BRAF mutation in colorectal cancer patients: a retrospective study in Eastern China

Objective

To investigate the frequency and prognostic role of the human epidermal growth factor receptor 2 gene (HER2) and BRAF V600E gene mutation in Chinese patients with colorectal cancer (CRC).

Methods

Clinicopathological and survival information from 480 patients with stage I–III CRC were reviewed and recorded. HER2 amplification was analyzed by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), BRAF V600E mutation was tested by IHC and Sanger sequencing. The relationship between HER2 and BRAF V600E mutation status and clinicopathological characteristics and outcomes were determined.

Results

The amplification of HER2 and BRAF V600E mutation were identified in 27 of 480 (5.63%) and 19 of 480 (3.96%) CRC patients, respectively. HER2 amplification significantly correlated with greater bowel wall invasion (P = 0.041) and more advanced TNM stage (I vs. II vs. III; 0 vs 5.78% vs. 7.41%, P = 0.013). Patients suffering from tumors with poor differentiation had a higher incidence rate of BRAF V600E mutation than those with moderate/well differentiation (7.77% vs 2.92%, P = 0.04). HER2 amplification was an independent prognostic factor for worse disease-free survival (DFS) (HR = 2.53, 95% CI: 1.21–5.30, P = 0.014).

Conclusion

The prevalence of HER2 amplification and BRAF V600E mutation in stage I–III CRC patients in Chinese was 6% and 4%, respectively, and HER2 amplification appeared to be associated with a worse DFS. More comprehensive molecular classification and survival analysis are needed to validate our findings.

Baseline derived neutrophil-to-lymphocyte ratio as a prognostic biomarker for non-colorectal gastrointestinal cancer patients treated with immune checkpoint blockade

BACKGROUND

Biomarkers in non-colorectal gastrointestinal (GI) cancer patients receiving immune checkpoint blockades (ICBs) are still limited.

METHODS

Data were prospectively collected from a discovery cohort (n = 53) and a validation cohort (n = 107) in patients with non-colorectal GI cancer receiving ICB, as well as a chemotherapy-only cohort (n = 171). System inflammatory markers and derived neutrophil-to-lymphocyte ratio (dNLR) were determined as biomarkers by univariate and multivariate analyses.

RESULTS

A higher level of dNLR (cutoff = 3) was associated with shorter overall survival (OS) in discovery and validation cohorts. In pooled cohort, disease control rate (DCR) (28% vs. 48.1%) was associated with dNLR (p = .017). In univariate analysis, original tumor site, tumor histopathology, number of metastases, and dNLR were correlated with OS. In multivariate analysis, higher dNLR level was correlated with reduced OS (10.43 months vs. 4.20 months, p < .001). In chemotherapy-only cohort, dNLR was also correlated with DCR and OS.

CONCLUSION

Higher dNLR level was correlated with worse outcomes, suggesting that dNLR may help risk-group stratification and assist disease management strategies as a prognostic biomarker for non-colorectal GI patients receiving ICB.

Is microsatellite instability-high really a favorable prognostic factor for advanced colorectal cancer? A meta-analysis

Background

Stage II colorectal cancer with microsatellite instability-high (MSI-H) has been proven to have a better prognosis. However, in advanced stage, this trend remains controversial. This study aimed to explore the prognostic role of MSI-H in stage III and IV colorectal cancer (CRC) through meta-analysis.

Methods

A comprehensive search was performed in PubMed, Cochrane Central Library, and Embase databases. All randomized clinical trials and non-randomized studies were included based on inclusion and exclusion criteria and on survival after a radical operation with or without chemotherapy. The adjusted log hazard ratios (HRs) were used to estimate the prognostic value between MSI-H and microsatellite-stable CRCs. The random-effects model was used to estimate the pooled effect size.

Results

Thirty-six studies were included. Randomized controlled trials (RCT) and non-RCT were analyzed separately. For stage III CRCs, pooled HR for overall survival (OS) was 0.96 (95% confidence interval [CI] 0.75–.123) in the RCT subgroup and 0.89 (95% CI 0.62–1.28) in the non-RCT subgroup. For disease-free survival (DFS), the HR for the RCT group was 0.83 (95% CI 0.65–1.07), similar to the non-RCT subgroup (0.83, 95% CI 0.65–1.07). Disease-specific survival (DSS) was also calculated, which had an HR of 1.07 (95% CI 0.68–1.69) in the non-RCT subgroup. All these results showed that MSI-H has no beneficial effects in stage III CRC. For stage IV CRC, the HR for OS in the RCT subgroup was 1.23 (95% CI 0.92–1.64) but only two RCTs were included. For non-RCT study, the combined HR for OS and DFS was 1.10 (95% CI 0.77–1.51) and 0.72 (95% CI 0.53–0.98), respectively, suggesting the beneficial effect for DFS and non-beneficial effect for OS.

Conclusion

For stage III CRC, MSI-H had no prognostic effect for OS, DFS, and DSS. For stage IV CRC, DFS showed a beneficial result, whereas OS did not; however, the included studies were limited and needed further exploration.

Colorectal cancer mutations are associated with survival and recurrence after pulmonary metastasectomy

BACKGROUND AND OBJECTIVES

While knowledge has grown extensively regarding the impact of mutations on colorectal cancer prognosis, their role in outcomes after pulmonary metastasectomy (PM) remains minimally understood. We sought to determine the prognostic role of mutant disease on survival and recurrence after metastasectomy.

METHODS

Patients with available tumor sequencing profiles who underwent PM for colorectal cancer at a single institution from 2011 to 2017 were reviewed. Various demographic and clinicopathologic factors, as well as mutational status, were tested in the Cox regression analyses to identify predictors of survival and disease-free survival (DFS).

RESULTS

A total of 130 patients met inclusion criteria, among whom 78 (60%) were male and the mean age was 57 years. The median survival time and 5-year survival rate were 58.2 months and 47%, respectively. A single pulmonary nodule was present in 54%. Disease recurrence occurred for 87 (67%) patients, including 75 (58%) who had at least one lung recurrence after metastasectomy at a median time to recurrence of 19.4 months. Upon multivariable analysis, RAS and TP53 mutations were associated with shorter survival DFS, while APC is associated with prolonged survival.

CONCLUSIONS

After metastasectomy for colorectal cancer, mutations in RAS, TP53, and APC play an important role in survival and recurrence.

Pathological and Molecular Characteristics of Colorectal Cancer with Brain Metastases

Background: Colorectal cancers (CRC) with brain metastases (BM) are scarcely described. The main objective of this study was to determine the molecular profile of CRC with BM. Methods: We included 82 CRC patients with BM. KRAS, NRAS, BRAF and mismatch repair (MMR) status were investigated on primary tumors (n = 82) and BM (n = 38). ALK, ROS1, cMET, HER-2, PD-1, PD-L1, CD3 and CD8 status were evaluated by immunohistochemistry, and when recommended, by fluorescence in situ hybridization. Results: In primary tumors, KRAS, NRAS and BRAF mutations were observed in 56%, 6%, and 6% of cases, respectively. No ROS1, ALK and cMET rearrangement was detected. Only one tumor presented HER-2 amplification. Molecular profiles were mostly concordant between BM and paired primary tumors, except for 9% of discordances for RAS mutation. CD3, CD8, PD-1 and PD-L1 expressions presented some discordance between primary tumors and BM. In multivariate analysis, multiple BM, lung metastases and PD-L1+ tumor were predictive of poor overall survival. Conclusions: CRCs with BM are associated with high frequency of RAS mutations and significant discordance for RAS mutational status between BM and paired primary tumors. Multiple BM, lung metastases and PD-L1+ have been identified as prognostic factors and can guide therapeutic decisions for CRC patients with BM.

Prognostic value of the systematic immune-inflammation index among patients with operable colon cancer: A retrospective study

The systematic immune-inflammation index (SII) has been used to predict the prognosis of patients with various cancers. This study aimed to determine whether the preoperative SII was associated with postoperative survival among patients with operable colon cancer.This retrospective study included 118 age- and sex-matched healthy subjects and 118 patients who underwent radical surgery for colon cancer between January 2011 and December 2013. The preoperative SII was calculated based on counts of neutrophils, lymphocytes, and platelets in the peripheral blood. Pearson correlation analysis was used to analyze the relationships between the SII and carcinoembryonic antigen (CEA) concentration, average length of stay (ALOS), and medical costs during hospitalization. The χ test or Fisher exact test was used to analyze the relationship between the preoperative SII and the postoperative survival rate.The median SII value was 667.75 among patients with colon cancer, which was higher than the value among healthy subjects. A high SII (>667.75) was associated with a large tumor size and advanced TNM stage, although it was not associated with age, sex, tumor location, or pathological grade. Pearson correlation analysis revealed that the SII was positively correlated with serum CEA concentration, ALOS, and medical costs. Relative to a low SII, a high SII was significantly associated with a lower overall survival rate at 3 years and 5 years after surgery.The present study's findings suggest that the preoperative SII is a useful prognostic index for patients with operative colon cancer.