Head and neck cancer: heterogeneous cancers from this region

Head and neck cancer is a term used to describe various different malignant tumors that develop in or around the throat, larynx, nose, sinuses, and mouth.

Most head and neck cancers are squamous cell carcinomas. This type of cancer begins in the flat, squamous cells that form the thin layer of tissue on the surface of structures in the head and neck. Directly beneath this lining, called the epithelium, some areas of the head and neck have a moist tissue layer called the mucosa. If a cancer is confined to the squamous cell layer, it is called carcinoma in situ. If the cancer has grown beyond this layer of cells and has moved into deeper tissue, it is referred to as invasive squamous cell carcinoma.

If a head and neck cancer originates in the salivary glands, the tumor is usually classified as an adenocarcinoma, adenoid cystic carcinoma, or mucoepidermoid carcinoma.

There are many types of head and neck cancer. Your doctor can provide more information about the specific type you have. Here are some of the most common types and their descriptions:

• Oral cavity cancer: begins in the mouth
• Oropharyngeal cancer: begins in the back of the mouth or throat
• Nasal cavity cancer: starts in the space behind the nose that extends along the top of the roof of the mouth and then curves down to join the back of the mouth and throat
• Paranasal sinus cancer: originates in the openings around or near the nose called sinuses
• Nasopharyngeal cancer: begins in the upper part of the throat, behind the nose.
• Laryngeal cancer: starts in the voice box
• Hypopharyngeal cancer: starts in the lower part of the throat, beside and behind the voice box

The most common type of head and neck cancer is called carcinoma. These cancers begin in the cells lining all parts of the nose, mouth, and throat.

Main risk factors for head and neck cancer are:

• Sex
• Age
• Race
• Prolonged sun exposure
• Epstein-Barr virus (EBV) infection
• Poor oral and dental hygiene
• Environmental or occupational inhalants
• Drug, tobacco, and alcohol use
• Poor vitamin nutrition
• Weakened immune system

• Swelling or sore that does not heal (the most common symptom)
• Red or white patch in the mouth
• Lump, bump, or mass in the head or neck area, with or without pain
• Persistent sore throat
• Unexplained bad breath
• Hoarseness or voice changes
• Persistent nasal obstruction or congestion
• Frequent nosebleeds and/or unusual nasal discharge
• Difficulty breathing
• Double vision
• Numbness or weakness in part of the head and neck region
• Pain or difficulty chewing, swallowing, or moving the jaw or tongue
• Ear and/or jaw pain
• Blood in saliva or mucus discharged from the respiratory tract
• Tooth loss
• Dentures that no longer fit
• Unexplained weight loss
• Fatigue

The 5-year relative survival rates for oral cavity and pharyngeal (throat) cancers are approximately 83% for cancers that have not spread, 62% for cancers that have spread to nearby lymph nodes, and 38% for cancers that have spread to distant parts of the body.

For nasal cavity and paranasal sinus cancers, the 5-year survival rates are similar in early stages (I and II), around 60%. In more advanced stages (III and IV), survival rates vary between 50% and 35%, respectively.

In laryngeal cancer, the overall 5-year survival rate is around 90% in stage I, dropping to 70% in stage II. In stage III, approximately 60% of individuals survive, while in stage IV, this probability decreases significantly to around 25%.

IMPORTANT: EARLY DIAGNOSIS OF CANCER IS CRUCIAL SINCE A CANCER DIAGNOSED AT AN EARLY STAGE — BEFORE IT HAS GROWN SIGNIFICANTLY OR SPREAD TO OTHER PARTS OF THE BODY — HAS A HIGHER CHANCE OF SUCCESSFUL TREATMENT. IN CONTRAST, IF THE CANCER HAS SPREAD TO OTHER ORGANS, ITS TREATMENT BECOMES MORE CHALLENGING, AND SURVIVAL PROBABILITY IS MUCH LOWER.

In the past, various methods have been developed to diagnose head and neck cancer. Some of the most common procedures used for this purpose include physical exams, endoscopies, biopsies, and imaging techniques such as X-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI), or positron emission tomography (PET) scans. However, these procedures have inherent limitations for several reasons: firstly, they can cause stress to the patient; secondly, some may be harmful (e.g., X-rays or endoscopies) and may damage tissues during the examination; and finally, these procedures add significant costs throughout the treatment process.