Targeted therapy is a type of cancer treatment that uses drugs or other substances specifically designed to target and attack cancer cells while causing minimal damage to normal cells. These therapies work by focusing on specific molecules and signaling pathways that are involved in the growth, progression, and spread of cancer cells. In the treatment of melanoma, targeted therapies have become a critical component, particularly for advanced stages of the disease.

Mechanism of Action

1. Specific Target Molecules
   • BRAF Mutation: Approximately 40-50% of melanomas have a mutation in the BRAF gene, which produces a protein that signals melanoma cells to grow and divide. Targeted therapies for BRAF mutations inhibit this protein, thereby slowing or stopping the growth of cancer cells.
   • MEK Proteins: MEK proteins are part of the same pathway as BRAF, and targeting MEK can help inhibit melanoma growth further when used in combination with BRAF inhibitors.

Types of Targeted Therapies for Melanoma

1. BRAF Inhibitors
   • Vemurafenib (Zelboraf)
   • Dabrafenib (Tafinlar)
   • Mechanism: These drugs block the activity of the mutant BRAF protein, reducing cancer cell growth.
   • Sources: American Cancer Society, Mayo Clinic
2. MEK Inhibitors
   • Trametinib (Mekinist)
   • Cobimetinib (Cotellic)
   • Mechanism: These drugs inhibit the MEK proteins in the pathway, providing an additional blockade to the signals promoting cancer cell growth.
   • Combination Therapy: Often used in combination with BRAF inhibitors for a more effective treatment strategy.
   • Sources: American Cancer Society, National Cancer Institute
3. KIT Inhibitors
   • Imatinib (Gleevec)
   • Nilotinib (Tasigna)
   • Mechanism: For melanomas with mutations in the KIT gene, these drugs block the activity of the KIT protein, which can help control the growth of the cancer.
   • Sources: American Cancer Society, National Cancer Institute

Use in Melanoma Treatment

1. Advanced Melanoma
   • Indications: Targeted therapy is primarily used for advanced melanoma, including metastatic melanoma or melanoma that cannot be surgically removed.
   • Personalized Medicine: Genetic testing of the melanoma cells is crucial to determine if the cancer has specific mutations (e.g., BRAF, MEK, KIT) that can be targeted by these therapies.
2. Combination Therapies
   • BRAF and MEK Inhibitors: Using both inhibitors together has been shown to be more effective than using either alone. This combination helps in delaying the resistance that melanoma cells can develop against treatment.
   • Sources: National Cancer Institute, Mayo Clinic
3. Managing Side Effects
   • Common Side Effects: Targeted therapies can cause side effects such as rash, fever, fatigue, joint pain, and liver problems. Managing these side effects is an important part of the treatment plan.
   • Monitoring and Adjustment: Regular monitoring and dose adjustments are often necessary to balance effectiveness and tolerability.
   • Sources: American Cancer Society, National Cancer Institute

Conclusion

Targeted therapy represents a significant advancement in the treatment of melanoma by focusing on specific genetic mutations and pathways that drive cancer growth. By targeting these specific abnormalities, these therapies offer a more personalized and effective approach to melanoma treatment, especially for advanced cases.

Further Reading

• American Cancer Society: Treating Melanoma Skin Cancer with Targeted Therapy
• National Cancer Institute: Targeted Cancer Therapies
• Mayo Clinic: Targeted Therapy

These resources provide comprehensive information on targeted therapy and its role in treating melanoma, helping patients and caregivers understand the available options and their potential benefits.