Targeted Cancer Therapy

Targeted cancer therapy, also known as precision medicine or personalized medicine, is an approach to cancer treatment that focuses on identifying and attacking specific molecular or genetic features of cancer cells. Unlike traditional treatments such as chemotherapy, which can damage healthy cells along with cancerous ones, targeted therapy aims to be more selective and precise in its attack on cancer cells. This approach offers several advantages, including potentially fewer side effects and improved treatment outcomes.

Molecular Targets

Targeted therapies are designed to interfere with specific molecules or pathways that are crucial for the growth and survival of cancer cells. These targets can include proteins, genes, or other molecular components involved in cell division, growth, and spread of cancer.

Biomarker-Based Treatment

To determine which targeted therapy is most appropriate for a patient, oncologists often rely on biomarker testing. Biomarkers are specific genetic or molecular characteristics of a patient's tumor that can help identify which treatment is most likely to be effective. Common biomarkers include mutations in genes like EGFR, HER2, BRAF, and ALK.

Examples of Targeted Therapies

There are many targeted therapies available for various types of cancer. Some examples include:

• Tyrosine Kinase Inhibitors (TKIs): These drugs block the action of certain enzymes involved in cell growth and division. Examples include imatinib (Gleevec) for chronic myeloid leukemia (CML) and erlotinib (Tarceva) for non-small cell lung cancer (NSCLC).
• Monoclonal Antibodies: These drugs target specific proteins on the surface of cancer cells. Trastuzumab (Herceptin) is an example used for HER2-positive breast cancer.
• PARP Inhibitors: These drugs are used in some breast and ovarian cancers, often in patients with BRCA mutations. They interfere with the repair of DNA in cancer cells.

Resistance

Over time, cancer cells can develop resistance to targeted therapies. This can occur through various mechanisms, such as mutations in the targeted gene or activation of alternative signaling pathways. Combination therapies or periodic reassessment of treatment options may be necessary to overcome resistance.

Side Effects

While targeted therapies are generally associated with fewer side effects compared to traditional chemotherapy, they can still cause adverse effects, depending on the specific drug and the patient's individual response. Common side effects can include skin problems, gastrointestinal issues, and blood disorders.

Patient Selection

Targeted therapy is not suitable for all cancer patients. It is typically used in cases where the specific molecular target is present in the tumor and when the potential benefits outweigh the risks. Therefore, proper patient selection is critical.

Research and Development

Ongoing research continues to identify new molecular targets and develop new targeted therapies. This field is dynamic, and treatment options are continually evolving.