Reevaluating the prognostic role of BRAF mutation in colorectal cancer liver metastases

BRAF mutations and survival with surgery for colorectal liver metastases: A systematic review and meta-analysis

INTRODUCTION

Mutations in the BRAF gene (BRAFmut) are associated with an unfavorable prognosis in patients with metastatic colorectal cancer (CRC). The aim of this meta-analysis was to evaluate the prognosis of colorectal cancer (CRC) patients with liver metastases and the potential benefits of liver resection in patients with BRAFmut CRC.

MATERIAL AND METHODS

A systematic search of PubMed, Cochrane Central Controlled Trials, and Embase databases was conducted on May 31, 2023. The inclusion criteria were as follows:1) reporting of outcomes in patients with BRAFmut CRC who underwent surgery for liver metastases and/or comparison of outcomes between those who underwent and those who did not undergo resection; 2) reporting of survival information as hazard ratios (HR); and 3) publication in English.

RESULTS

34 studies were included. Median follow up was 48 months for prognostic BRAF status meta-analysis. BRAFmut status showed a significantly increased risk of mortality (hazard ratio [HR] = 2.56, 95% confidence interval [CI] 2.04-3.22; P < 0.01) and relapse (HR = 1.97, 95% CI 1.44-2.71; P < 0.01). Resection of liver metastases was associated with a survival benefit (median follow up 46 months). The HR for survival was 0.44 (95% confidence interval [CI] 0.33-0.59; P < 0.01) in favor of surgery.

CONCLUSIONS

and Relevance: Our analysis indeed confirms that BRAF mutation is associated with poor survival outcomes after liver resection of CRC metastases. However, upon quantitatively assessing the survival benefit of surgical intervention in patients with BRAF-mutated CRC liver metastases, we identified a significant 56% reduction in the risk of death.

Impact of Molecular Status on Metastasectomy of Colorectal Cancer Liver Metastases

Although surgical resection could provide better survival for patients with colorectal cancer liver metastases (CRLM), the recurrence rate after resection of CRLM remains high. The progress of genome sequencing technologies has greatly improved the molecular understanding of colorectal cancer. In the era of genomics and targeted therapy, genetic mutation analysis is of great significance to guide systemic treatment and identify patients who can benefit from resection of CRLM. RAS and BRAF mutations and microsatellite instability/deficient deoxyribonucleic acid (DNA) mismatch repair status have been incorporated into current clinical practice. Other promising molecular biomarkers such as coexisting gene mutations and circulating tumor DNA are under active investigation. This study aimed to review the prognostic significance of molecular biomarkers in patients with CRLM undergoing metastasectomy based on the current evidence.

The Role of Biomarkers in the Management of Colorectal Liver Metastases

Simple Summary

Colorectal cancer remains one of the most significant sources of cancer-related morbidity and mortality worldwide. The liver is the most common site of metastatic spread. Multiple modalities exist to manage and potentially cure patients with metastatic colorectal cancer. However, reliable biomarkers to assist with clinical decision-making are limited. Recent advances in genomic sequencing technology have greatly expanded our knowledge of colorectal cancer carcinogenesis and significantly reduced the cost and timing of the investigation. In this article, we discuss the current utility of biomarkers in the management of colorectal cancer liver metastases.

Abstract

Surgical management combined with improved systemic therapies have extended 5-year overall survival beyond 50% among patients with colorectal liver metastases (CRLM). Furthermore, a multitude of liver-directed therapies has improved local disease control for patients with unresectable CRLM. Unfortunately, a significant portion of patients treated with curative-intent hepatectomy develops disease recurrence. Traditional markers fail to risk-stratify and prognosticate patients with CRLM appropriately. Over the last few decades, advances in molecular sequencing technology have greatly expanded our knowledge of the pathophysiology and tumor microenvironment characteristics of CRLM. These investigations have revealed biomarkers with the potential to better inform management decisions in patients with CRLM. Actionable biomarkers such as RAS and BRAF mutations, microsatellite instability/mismatch repair status, and tumor mutational burden have been incorporated into national and societal guidelines. Other biomarkers, including circulating tumor DNA and radiomic features, are under active investigation to evaluate their clinical utility. Given the plethora of therapeutic modalities and lack of evidence on timing and sequence, reliable biomarkers are needed to assist clinicians with the development of patient-tailored management plans. In this review, we discuss the current evidence regarding biomarkers for patients with CRLM.

BRAF Mutations in Colorectal Liver Metastases: Prognostic Implications and Potential Therapeutic Strategies

Simple Summary

In this literature review, we investigated the relationship between BRAF mutation and prognosis in patients with colorectal cancer liver metastases. We also investigated factors affecting the prognosis of patients with BRAF mutations and summarized the latest research on targeted therapies.

Abstract

Surgery combined with chemotherapy and precision medicine is the only potential treatment for patients with colorectal cancer liver metastases (CRLM). The use of modern molecular biotechnology to identify suitable biomarkers is of great significance for predicting prognosis and formulating individualized treatment plans for these patients. BRAF mutations, particularly V600E, are widely believed to be associated with poor prognosis in patients with metastatic CRC (mCRC). However, it is unclear which specific factors affect the prognosis of CRLM patients with BRAF mutations. It is also unknown whether patients with resectable CRLM and BRAF mutations should undergo surgical treatment since there is an increased recurrence rate after surgery in these patients. In this review, we combined the molecular mechanism and clinical characteristics of BRAF mutations to explore the prognostic significance and potential targeted therapy strategies for patients with BRAF-mutated CRLM.

Antiangiogenic Drug-Induced Proteinuria as a Prognostic Factor in Metastatic Colorectal Cancer

Treatment with bevacizumab is known to cause adverse events such as proteinuria and hypertension, amongst others. However, while bevacizumab-induced hypertension has been linked to increased overall survival (OS), data on proteinuria are controversial. We performed a retrospective analysis to observe the influence of adverse events developed during treatment with bevacizumab and chemotherapy on the OS in patients with metastatic colorectal cancer (mCRC). Kaplan–Meier and log-rank analyses were used to assess differences in OS, and hazard ratios (HR) were estimated using Cox models. Out of the 3497 mCRC patients admitted to our center between 2014 and 2019, 150 met the criteria for inclusion in our analysis. Out of these, 50.7% experienced proteinuria and had reached a longer OS (40 versus 25 months, p = 0.015) and progression-free survival (15 versus 12 months, p = 0.039). The following groups were identified as having a lower risk of death: patients with proteinuria (HR 0.589; 95% CI 0.402–0.863; p = 0.007), one metastatic site (HR 0.533; 95% CI 0.363–0.783; p = 0.001), and non-metastatic stage at diagnosis (HR 0.459; 95% CI 0.293–0.720; p = 0.001). Patients with anemia and diabetes had an increased risk of death. Proteinuria emerges as a useful prognostic factor in mCRC patients undergoing bevacizumab-based systemic therapy, and it could be easily integrated into the decision-making process, thus allowing physicians to further individualize systemic treatments.