Which Drug Is Used As a Targeted Therapy for Head and Neck Cancer?

Targeted therapy is a type of cancer treatment that uses targeted cancer therapies (drugs) designed to target the cancer cells exclusively without affecting normal cells.

Genetic changes in the cancer cells allow them to grow, divide, and spread very quickly with certain proteins or enzymes necessary for them to thrive.

Targeted therapy drugs block the growth and spread of cancer cells by interfering with these specific molecules (molecular targets) that are involved in the growth, progression, and spread of cancer. They can even signal the cancer cells to destroy themselves.

Targeted therapy is different from standard chemotherapy in two mechanisms:

1. These drugs target only the cancer cells, whereas traditional chemotherapy is cytotoxic to most cells including the normal, healthy cells in addition to cancer cells.
2. Targeted drugs work by preventing a cancer cell from dividing and producing new cancer cells, whereas chemotherapy kills already made cancer cells.

Targeted therapies find and attack specific areas or substances in the cancer cells or detect and block certain messages inside a cancer cell that made them grow.

Some of the substances (proteins and enzymes) that can become the targets of these drugs include:

• Excess of a certain protein on a cancer cell
• A protein present exclusively on a cancer cell and not on the normal cells
• A mutated or changed protein on a cancer cell
• Genetic (DNA) changes that cannot be found in the normal cells

These targeted therapy drugs work by:

• Blocking the chemical signals that make cancer cell cells and divide.
• Changing the proteins within the cancer cells leads to their death.
• Preventing new blood vessels to form (neovascularization), thus leading to cell starvation.
• Triggering the immune system to kill the cancer cells.
• Carrying toxins to the cancer cells to kill them.

Targeted therapy is known as precision medicine or personalized medicine because it is made to target specific changes or substances in cancer cells that are classified as small (targets and blocks a specific substance inside the cancer cell) or large molecule drugs (attacks and destroys proteins or enzymes on the cell surface).

Four types of targeted therapy include:

1. Angiogenesis inhibitors: These drugs prevent the formation of new blood vessels, thus preventing nourishment to the cancer cells.
   • Bevacizumab is used for many types of cancer.
2. Proteasome inhibitors: These drugs disrupt the breakdown of certain proteins that interfere with cell functioning leading to cancer cell death.
   • Bortezomib is used in multiple myeloma.
3. Signal transduction inhibitors: These drugs disrupt cell signals, preventing cancer cell growth and division.
   • Imatinib is used in certain leukemias.
4. Monoclonal antibodies: Monoclonal antibodies are lab-made immune system proteins that target and kill cancer cells.
   • Alemtuzumab is used in certain chronic leukemias.
   • Trastuzumab is used in certain types of breast cancer.
   • Cetuximab is used in colorectal, lung, head, and neck cancer.

Head and neck cancer are malignant tumors that usually arise in the cells that line the mucous membranes of the mouth, nose, and throat.

Head and neck cancer account for approximately four percent of all types of cancer in the United States.

Based on their location, head and neck cancer can be divided into the following:

• Laryngeal and hypopharyngeal cancer
• Nasal cavity and paranasal sinus cancer
• Nasopharyngeal cancer
• Oral and oropharyngeal cancer
• Salivary gland cancer

Most head and neck cancer are squamous cell carcinomas that begin in the flat squamous cells that make up the thin layer of tissue on the inner surface of the structures in the head and neck.

Other types include:

• Carcinoma in situ: Cancer is only found in the squamous layer of cells
• Invasive squamous cell carcinoma: Cancer that has grown beyond the cell layer and moved into the deeper tissues
• Cancer of unknown primary: The origin of the cancer is unknown

Certain factors increase the odds of developing head and neck cancer including:

• People older than 40 years
• Men are two to three times more likely than women 
• Poor oral and dental hygiene
• A diet low in vitamins A and B
• Weakened immune system
• Prolonged sun exposure
• Human papillomavirus infection
• Epstein–Barr virus infection
• Environmental or occupational inhalants such as asbestos, wood dust, paint fumes, and certain chemicals
• Gastroesophageal reflux disease and laryngopharyngeal reflux disease
• Previous history of head and neck cancer
• Exposure to radiation
• Substance abuse such as tobacco and marijuana
• Heavy alcohol consumption

The signs and symptoms of head and neck cancer include:

• Swelling or a sore that does not heal
• Red or white patches in the mouth
• Lump, bump, or mass in the head or neck area, with or without pain
• Persistent sore throat
• Foul mouth odor
• Hoarseness or change in voice
• Nasal obstruction
• Persistent nasal congestion
• Frequent nose bleeds
• Unusual nasal discharge
• Difficulty breathing
• Double vision
• Numbness or weakness in the head and neck region
• Pain or difficulty chewing, swallowing, or moving the jaw or tongue
• Jaw pain
• Blood in the saliva or phlegm
• Loosening of teeth
• Unexplained weight loss
• Fatigue
• Ear pain or infection

Head and neck cancer can be managed by the following:

• Chemotherapy
• Targeted therapy
• Immunotherapy
• Radiation therapy
• Surgery
  • Laser technology
  • Lymph node dissection or neck dissection
  • Excision
  • Reconstructive (plastic) surgery