Progress in clinical diagnosis and treatment of colorectal cancer with rare genetic variants

Targeted therapy is crucial for advanced colorectal cancer (CRC) positive for genetic drivers. With advances in deep sequencing technology and new targeted drugs, existing standard molecular pathological detection systems and therapeutic strategies can no longer meet the requirements for careful management of patients with advanced CRC. Thus, rare genetic variations require diagnosis and targeted therapy in clinical practice. Rare gene mutations, amplifications, and rearrangements are usually associated with poor prognosis and poor response to conventional therapy. This review summarizes the clinical diagnosis and treatment of rare genetic variations, in genes including erb-b2 receptor tyrosine kinase 2 (ERBB2), B-Raf proto-oncogene, serine/threonine kinase (BRAF), ALK receptor tyrosine kinase/ROS proto-oncogene 1, receptor tyrosine kinase (ALK/ROS1), neurotrophic receptor tyrosine kinases (NTRKs), ret proto-oncogene (RET), fibroblast growth factor receptor 2 (FGFR2), and epidermal growth factor receptor (EGFR), to enhance understanding and identify more accurate personalized treatments for patients with rare genetic variations.