What is salivary gland cancer?

Salivary gland cancer is a very rare malignant tumour disease that affects the area of the head salivary gland. The disease is particularly common in the parotid gland (parotid carcinoma). Salivary gland cancer can cover any age category, but affects patients between 50 and 70 years of age more often than average . Children are affected rather less frequently . Salivary gland cancer tends to form again or metastasise after successful treatment.

What are the different types of salivary gland cancer?

There are different types of salivary glands, such as the large head salivary gland, the submaxillary salivary gland or the parotid gland. Each of these is made up of many different cell types, which in principle can develop into a tumour. Doctors distinguish the different types of salivary gland cancer according to the respective cell type. Salivary gland cancer occurs particularly often in the parotid gland and grows relatively quickly. They can infiltrate the surrounding tissue and may even metastasise to the neighbouring lymph nodes or to the lungs. Examples of this are:

• adenocystic carcinoma (AZK): is an aggressive form of tumour that forms along the facial nerves, the so-called facial nerve. It forms metastases early on, usually to the lungs or bones, and in some cases of the disease forms again after successful treatment (recurrence).
• the mucoepidermoid carcinoma (MEK): is the most common form of salivary gland carcinoma and usually arises in the parotid glands, but can also occur less frequently in the minor salivary glands in the mouth or the sublingual gland. An above-average number of people around the age of 50 develop MEK, and women are more often affected than men. If it develops in children or adolescents , it takes a less aggressive course than in adults. Characteristic of a MEK is its barely perceptible demarcation from the neighbouring tissue and its tendency to grow into the surrounding tissue .
• acinar cell carcinoma: is a malignant tumour that arises from certain glandular cells, the so-called acinar cells, of the salivary gland. Acinar cell carcinoma is more common in younger patients than in other forms of salivary gland cancer. Acinar cell carcinoma is the second most common form of salivary gland cancer in children.

What causes salivary gland cancer to form?

As with other types of cancer, salivary gland cancer develops through the change of originally healthy cells. This change causes the cells to suddenly multiply unhindered and displace the healthy tissue. The exact cause of this transformation is still not known. However, doctors assume that several factors interact in the development of salivary gland cancer. However, a genetic disposition is excluded.

Patients who received radiation therapy in the head and neck area in childhood have a higher risk of developing salivary gland cancer. However, smoking and contact with certain viruses such as the Epstein-Barr virus or the human papilloma virus (HPV) as well as ionising radiation can also increase the likelihood of developing salivary gland cancer.

What are the symptoms of salivary gland cancer?

Characteristic of salivary gland cancer is an increasing swelling of the salivary gland, which does not cause any pain at first. As the disease progresses, both the swelling and the symptoms can increase. Due to the size of the tumour, the following symptoms may occur:

• Difficulty swallowing,
• Problems speaking,
• dry mouth,
• Tingling and/or numbness up to unilateral facial paralysis (paraesthesia), if the facial nerve (Nervus facialis), which runs through the parotid gland, is affected.

How is salivary gland cancer diagnosed?

If salivary gland cancer is suspected , the patient should contact an otorhinolaryngologist ( ). The doctor will check the diagnosis in an initial consultation. In an initial consultation, the doctor will take the patient's medical history ( ) and ask about the existing complaints. The patient is then examined clinically, paying particular attention to possible changes in the facial area and the oral cavity. If there are palpable swellings or nodules in the salivary gland area or in the area of the cervical lymph nodes, these can be the first signs of a possible tumour disease.

The usual imaging methods such as ultrasound (sonography) and computer (CT) and magnetic resonance imaging (MRI) are used to make a reliable diagnosis. These procedures can be used to determine the nature of the tumour, but also to clarify the question of whether the tumour has already grown into the surrounding tissue and/or possibly even already formed metastases. In addition, a blood test can also indicate the patient's general state of health . However, there are no specific blood values that could indicate salivary gland cancer.

How is salivary gland cancer treated?

Regardless, whether it is a benign or malignant tumour of the salivary gland , the first choice of treatment is always complete surgical removal. This is because even benign tumours can become malignant over time. Within the operation, the salivary gland is removed either completely (paroidectomy) or partially (partial paroidectomy). If the tumour can be completely removed, the treatment is usually complete, at least in childhood and adolescence. If, on the other hand, the tumour has already spread to the surrounding tissue, especially to the neighbouring lymph nodes , it is necessary to remove these as well. In this very extensive operation, doctors speak of a so-called "neck dissection". In some cases, it may also make sense to have radiotherapy after the operation.

What is the prognosis for salivary gland cancer?

Salivary gland cancer has a good prognosis in most cases and can be cured. The prospects of cure depend on different factors. As a rule, the survival rate is very high, provided that the salivary gland carcinoma

• the salivary gland carcinoma is well demarcated from the adjacent tissue and has not grown into the tissue,
• the tumour grows slowly,
• the tumour is located in the outer area of the parotid gland.