Metastatic colorectal cancer is one of the most common causes of cancer death worldwide.

Primary and acquired resistance mechanisms to anti-EGFR treatment are a challenging topic with several clinical implications.

Primary resistance is defined by the presence of activating mutations in BRAF and RAS genes before treatment initiation, while acquired resistance refers to the selection of pre-existing mutant clones or de novo acquisition of mutations under the pressure of anti EGFR treatment.

Testing mutations in RAS and BRAF genes as predictive biomarkers is mandatory.

Liquid biopsy has acquired growing importance and showed to be reliable when compared to tissue NGS.

Liquid biopsy offers a full overview of the genetic landscape of the disease, overcoming spatial and temporal heterogeneity, when compared to tissue biopsy.

Liquid biopsy can be used to capture the changes in biology of cancer cells under the selective pressure of targeted agents over time.

Using complementary techniques allows to increase the diagnostic power and the biological significance of the results.

转移性结直肠癌是全世界癌症死亡的最常见原因之一。

抗 EGFR 治疗的原发性和获得性耐药机制是一个具有若干临床意义的具有挑战性的课题。

原发性耐药定义为治疗开始前 BRAF 和 RAS 基因中存在激活突变，而获得性耐药是指在抗 EGFR 治疗的压力下选择预先存在的突变克隆或从头获得突变。

测试 RAS 和 BRAF 基因的突变作为预测性生物标志物是强制性的。

与组织 NGS 相比，液体活检变得越来越重要，并且显示出其可靠性。

与组织活检相比，液体活检提供了疾病遗传景观的完整概述，克服了空间和时间的异质性。

液体活检可用于捕获癌细胞在靶向药物的选择性压力下随时间推移而发生的生物学变化。

使用互补技术可以提高结果的诊断能力和生物学意义。