Targeted therapy is a form of cancer treatment that interferes with specific molecules involved in tumor growth and survival. Unlike traditional chemotherapy, which affects rapidly dividing cells in general, targeted therapies are designed to act on particular genetic or molecular abnormalities found in cancer cells, aiming to kill them or stop their proliferation while limiting damage to healthy tissue.

A central concept is the identification of “driver” mutations, changes in genes that push cells toward uncontrolled growth. Examples include mutations in EGFR, ALK, BRAF, and HER2. Molecular testing of tumors has become essential to detect these alterations and match patients with appropriate drugs. Targeted agents include small molecule inhibitors, which often block abnormal proteins inside cells, and monoclonal antibodies, which usually bind to targets on the cell surface or in the surrounding environment.

These treatments can inhibit growth signals, prevent formation of new blood vessels, trigger cancer cell death, or mark cells for immune destruction. Many have shown substantial benefits in specific cancers, such as certain lung cancers, breast cancers, and melanoma, often leading to longer survival and improved quality of life.

However, targeted therapy faces key challenges. Tumors frequently evolve resistance through additional mutations or alternative pathways. Not all patients with the same cancer type share the same targets, and some tumors lack clear druggable alterations. Side effects, while often different from chemotherapy, can still be significant. Current research focuses on discovering new targets, combining drugs to prevent resistance, using advanced sequencing to guide treatment choices, and integrating targeted therapy with immunotherapy for more durable responses.