Salivary gland cancer

The salivary glands make spit (saliva) and release saliva to keep the mouth and throat moist and help with swallowing and digesting food. There are 3 major (large) and over 600 minor (small) salivary glands.

Tumours of the salivary glands can be benign (not cancer) or malignant (cancer).

The 3 pairs of major salivary glands include: the Parotid Gland, Submandibular glands and Sublingual glands.

• Parotid Glands – are found just in front of the ears and behind the jaw. They move saliva into the mouth through a tube called the parotid duct. This tube opens on the inside of the cheek, near the upper molar teeth. The parotid gland is the largest salivary gland and most salivary tumours start here.
• Submandibular Glands – lie under the jawbone, one on each side. They release saliva into the mouth through a duct (tube) that opens in the floor of the mouth, under the tip of the tongue.
• Sublingual Glands – lie under the tongue, one on each side. They release saliva into the submandibular duct and are near the lingual nerves which give feeling and taste to the front of the tongue. The sublingual glands are the smallest of the major salivary glands.
• Minor Salivary Glands – There are hundreds of minor salivary glands throughout the mouth and throat. They can be found inside the mouth, just under the surface including the lips, cheeks and top of the mouth (soft palate).

The most common types of Salivary Gland cancers are:

• Mucoepidermoid carcinomas. Mostly common in the parotid glands.
• Adenoid Cystic Carcinoma (ACC): a rare type of cancer that usually develops in the salivary glands or other areas of the head and neck. Sometimes it can form in other parts of the body, including your skin, breast tissue, cervix or prostate gland.

Adenoid Cystic Carcinoma (ACC) is a rare form of salivary gland cancer

Adenoid Cystic Carcinoma (ACC) is a rare form of adenocarcinoma, a type of cancer that begins in glandular tissues (a group of cells that produce and release substances such as hormones into the bloodstream). ACC arises within glands most commonly in the major and minor salivary glands of the head and neck.

ACC accounts for about 1% of all cases of head and neck cancer. It is more prevalent in women, accounting for nearly two thirds of all new cases diagnosed.

The cause of ACC is currently unknown, however it does not appear to run in families. There is evidence that it likely develops from genetic changes that occur over the patient’s lifetime, and, although the changes may be caused by environmental exposures, there are no strong environmental risk factors for ACC that have been identified to date. The genetic mutations are only present in the cancer cells, and not in the egg and sperm cells which are passed on to the next generation.

Contrary to other head and neck cancers, lifestyle choices such as smoking or alcohol use are not linked to increased risk of ACC. Infection by the human papilloma virus (HPV) also does not seem to increase risk.

Symptoms

The main symptoms of salivary gland cancer is a lump or swelling in one of the glands on or near your jaw, or in your mouth or neck. These lumps tend to be tender or give shooting pains. Other symptoms can include numbness in part of your face and drooping on one side of your face.

Symptoms of Adenoid Cystic Carcinoma (ACC), include headaches and seizures but much depends on the tumour’s location. Tumours on the salivary glands may cause painless masses in the mouth or face. Tumours of the lacrimal gland (small almond-shaped structure that secretes tears and is located just above the upper, outer corner of each eye) cause a bulging eye or changes in vision. Those situated in the windpipe or voice box may cause respiratory symptoms or changes in speech.