Targeted Therapy

Core Concept: Cancer cells grow and multiply due to the presence of mutations or abnormal proteins in their genes. Targeted therapy targets these “defects” or “genetic changes” with extreme precision, much like a key opening a specific lock.

The Difference from Chemotherapy: Chemotherapy targets all rapidly dividing cells (both cancer cells and some healthy cells), whereas targeted therapy focuses on cancer cells based on their genetic fingerprint, reducing the impact on healthy cells.

Types of Targeted Therapy and How It Works

Targeted therapy is typically available in two main forms:

1. Oral Tablets or Pills (Small-Molecule Drugs): Able to enter cancer cells and shut down the internal signals that command the cell to grow.

2. Injections or Intravenous Infusions (Monoclonal Antibodies): Attach to the outer surface of the cancer cell to highlight it for the immune system to attack, or to block the signals the cell feeds on.

How Do We Know if Targeted Therapy is Right for Your Condition?

Targeted therapy is not used for all types of tumors or for every patient. To determine if it is suitable:

• We take a tissue sample (biopsy) from the tumor or rely on a specific blood test.

• We perform a molecular/genetic testing (Molecular/Genetic Testing) to look for the “genetic fingerprint” or mutation responsible for tumor growth.

If this mutation is found, targeted therapy becomes the most appropriate and highly effective choice.

Side Effects and Contraindications

Although targeted therapy is characterized by its precision and reduced impact compared to chemotherapy, it may cause certain symptoms that require monitoring:

• Common Side Effects: Skin rash or dryness, diarrhea, high blood pressure, or fatigue.

• Absolute and Relative Contraindications:

  • Absolute contraindications: Documented severe allergy to the active substance in the drug.

  • Relative contraindications: Certain underlying health issues involving the heart, liver, or kidneys; some targeted therapy drugs require close monitoring of these organs’ functions or dosage adjustments before starting.

Red Flags Requiring Urgent Medical Intervention

If you are taking targeted therapy and experience any of the following signs, you should contact the medical team or go to the hospital emergency room immediately:

1. High fever ($38^{\circ}\text{C}$ or $100.4^{\circ}\text{F}$ or higher) or signs of severe infection (such as chills).

2. Severe difficulty breathing or sudden, sharp chest pain.

3. Persistent severe diarrhea that does not respond to standard medications (more than 4 to 6 times a day) leading to dehydration.

4. Unusual bleeding or sudden bruising without a cause.

5. Severe and sudden swelling in the legs or face.