Targeted Therapy in Oncology: A Comprehensive Overview

Targeted therapy is an approach to cancer management that involves using drugs or other substances that target specific molecules and pathways involved in the growth, progression, and spread of cancer cells. This approach aims to selectively target the cancer cells while reducing the harmful effects on healthy cells, which can cause less side effects compared to traditional chemotherapy.

An illustrative diagram is shown below, depicting chemotherapy as an atomic explosion wherein all cells of the body get affected, whereas a targeted therapy acts only on its target i.e. cancer cells depicted as a sniper.

Some key aspects of targeted therapy in cancer management include:

1. Molecular targets: Targeted therapies are designed to target specific molecules or signalling pathways that are crucial for cancer cell survival, growth, and proliferation. These targets may include growth factor receptors, intracellular signalling proteins, and other molecules involved in cancer cell biology.

2. Personalized medicine: Targeted therapies are often used in a personalized approach, where the patient’s tumour characteristics, such as genetic mutations or biomarker profiles, are used to guide the selection of the appropriate targeted therapy.

3. Combination therapy: Targeted therapies are often used along with other cancer treatments, such as chemotherapy, radiation therapy, or other targeted agents, to enhance the effectiveness of the overall treatment regimen.

4. Improved outcomes: Targeted therapies have shown improved outcomes in various types of cancer, including lung cancer, breast cancer, and leukaemia. They have the potential for better tumour control, prolonged survival, and reduced side effects compared to traditional chemotherapy.

5. Ongoing research and development: The field of targeted therapy in cancer management is rapidly evolving, with ongoing research and development of new targeted agents, as well as the exploration of different combination strategies and the identification of new molecular targets.

Overall, targeted therapy represents a significant advancement in cancer management, allowing for more personalized and effective treatment approaches.

Targeted therapy plays a crucial role in the management of various malignancies. Here’s an overview of the role of targeted therapy in some common cancer types:

1. Breast Cancer:

• Targeted therapies target the HER2 receptor, which is overexpressed in about 20% of breast cancers.
• Cyclin-dependent kinase (CDK) inhibitors, such as target the cell cycle and are used in combination with hormonal therapy.
• Antibody-drug conjugates like trastuzumab-emtansine (T-DM1) combine a targeted antibody with a cytotoxic drug.

2. Lung Cancer:

• Tyrosine kinase inhibitors (TKIs) target specific genetic mutations in non-small cell lung cancer (NSCLC), such as EGFR mutations.
• Anaplastic lymphoma kinase (ALK) inhibitors target ALK gene rearrangements in NSCLC.
• Immunotherapies target the PD-1/PD-L1 pathway in NSCLC.

3. Colorectal Cancer:

• Anti-EGFR monoclonal antibodies are used in colorectal cancer with wild-type KRAS and NRAS genes.
• Angiogenesis inhibitors target the vascular endothelial growth factor (VEGF) pathway.

4. Chronic Myeloid Leukemia (CML):

• Tyrosine kinase inhibitors target the BCR-ABL fusion protein, which drives the development of CML.

5. Melanoma:

• BRAF inhibitors target the BRAF V600E mutation, which is present in about 50% of melanomas.
• Immune checkpoint inhibitors target the PD-1/PD-L1 pathway in melanoma.

These are just a few examples, and the role of targeted therapy continues to evolve as our understanding of cancer biology and the development of new targeted agents advances.