Head and neck cancer refers to cancers occurring within the anatomical regions of the face, head, and neck. These tumours commonly develop in the mouth, throat, upper oesophagus, sinuses, as well as around the face and the external ear. Tumours may also originate in the glands located in the mouth and neck region, such as the salivary glands, lymph nodes, and thyroid gland.
A tumour is an abnormal mass of tissue that forms when cells grow and divide more than they should or do not die when they should. Tumors may be benign (not cancer) or malignant (cancer). Benign tumors may grow large but do not spread into, or invade, nearby tissues or other parts of the body. Fortunately, the majority of tumours in the head and neck region are benign.
Most cancers tend to originate from squamous cells within the mucosal surfaces that line the head and neck region. Hence, they are called squamous cell cancers or SCC. Other types of cancers originate from the glands and are called adenocarcinoma or lymphoma depending on the cell origin.
The sub-regions for head and neck cancers are:
- Oral cavity (mouth) – lips, inner lining of the cheeks, hard and soft palate, tongue, as well as gums and tonsils.
- Larynx (voice box) – contains the vocal cords responsible for voice generation. The larynx leads to the windpipe and the lungs.
- Pharynx (throat) – a passageway that extends from the base of the skull to the level of the sixth cervical vertebra. It serves both the respiratory and digestive systems by receiving air from the nasal cavity and air, food, and water from the oral cavity. Cancer may arise within the three sub-regions of the pharynx:
- Nasopharynx – the upper part of the throat, behind the nose and nasal cavity.
- Oropharynx – includes the base of the tongue to the tonsils at the back of the throat.
- Hypopharynx – behind the voice box in the lower region of the throat that leads to the oesophagus.
- Nasal cavity and sinuses – the area within the nose. Sinuses are four paired cavities (spaces) within the head that produce mucus and impact the tone of our speech.
- Salivary glands – where saliva is produced to help digest food and protect against infections. These paired glands are divided into major and minor salivary glands. The most common tumours of the largest gland (parotid gland) are benign.
- Thyroid and parathyroid glands – these are not part of the aero-digestive tract. They are endocrine glands that secrete hormones which are chemical messengers that affect other organs in the body.
- Lymph glands – part of the body’s immune system. Lymph glands filter substances that travel through the lymphatic fluid, and they contain lymphocytes (white blood cells) that help the body fight infection and disease. Lymph glands are located throughout the body but are especially concentrated in the head and neck region because of its close proximity and exposure to the environment.
- Upper oesophagus – the segment that lies within the neck and is connected to the hypopharynx. The lower oesophagus is located within the thorax and abdomen instead.
- Skin covering for the head and neck region as well as the scalp.
- Cancers of the eye, ear, spine and brain are not classified under head and neck cancers.
Causes of head and neck cancer
- Cigarette and cigar smoking
- Chronic alcohol consumption
- Betel nut/leaf chewing
- Poor oral hygiene and dental caries
- Sharp and abrasive edges on teeth or dentures
- Human papillomavirus (HPV)
- Chronic reflux or GERD
- Exposure to wood and metal dust, and chemical inhalants for sinus cancer
Signs and symptoms of head and neck cancer
Cancer within each sub-region of the head and neck may be associated with a specific symptom. However, the commonest and more general symptoms are:
- A persistent lump in your neck
- Rapidly growing lump in your neck
- A growth or persistent ulcers in your mouth (even if they are not sore)
- Blood in your phlegm or mucus or bleeding from the nose (epistaxis)
- Difficulty swallowing
- Persistent throat discomfort or pain
- Hoarseness
- Unusual ulcers or pigmentation in the skin
If you are experiencing any of the symptoms above, please consult with your doctor. Your doctor will require further pertinent information such as the duration and frequency of the symptom(s), other associated symptoms and the presence of risk factors. This will enable a diagnosis or, at the very least, form a list of possible diagnoses (differential diagnoses).
It is important that a cancer is diagnosed as early as possible so that a cure may be obtained. This is usually achieved through surgery but other treatment modalities such as radiotherapy or chemotherapy may also be necessary. Providing immediate relief from symptoms is an important part of cancer treatment and a team of different specialists may be involved in providing that care.
