What is adenoid cystic carcinoma?
Adenoid cystic carcinoma (ACC) is a rare type of cancer that forms in glandular tissues most commonly in the head and neck, but it can also begin in other areas.
ACC often starts in the salivary glands in the neck, mouth or throat, which make saliva. Saliva keeps the mouth moist, helps you swallow food and protects the mouth against infections.
Malignant (cancerous) tumours have the potential to spread to other parts of the body through the blood stream or lymph vessels and form another tumour at a new site. This new tumour is known as secondary cancer or metastasis.
ACC is rare. Around 330 Australians are diagnosed with a salivary gland cancer each year. ACC can develop at any age but is more common in people aged 40 to 60 years.
Adenoid cystic carcinoma symptoms
ACC generally develops slowly, sometimes over several years, and may not cause symptoms. Most often it is diagnosed as a single tumour but may have spread to nearby lymph nodes by the time it is diagnosed in a small number of cases.
Rarely, ACC can spread along nerves or metastasise to other parts of the body (usually the lungs, liver or bone) and cause problems. It can also be unpredictable, growing slowly for a period of time and then suddenly growing quickly. ACC may behave differently in different people.
If you do have symptoms it will depend on where in the body the tumour is located and its size. Symptoms may include:
Salivary gland (produces saliva) – painless lump in the mouth, face or neck; numbness in the face; weakness in facial muscles (drooping in the face); problems swallowing or opening mouth
Lacrimal gland (produces tears) – bulging eye; changes in vision
Larynx (voice box) and trachea (windpipe) – hoarseness; changes in speech; difficulty breathing
Skin – pain; increased sensitivity; pus and/or blood discharge
Breast – slow growing lump that may be tender or cause pain. .
Causes of adenoid cystic carcinoma
The cause of ACC is not known. It might develop from genetic changes that happen during a person’s lifetime, rather than inheriting a faulty gene. ACC is not considered to be hereditary.
Diagnosis of adenoid cystic carcinoma
If your doctor thinks that you may have ACC, they will take your medical history, perform a physical examination (including feeling for any lumps) and carry out certain tests depending on the location of the suspected tumour.
If the results suggest that you may have ACC, your doctor will refer you to a specialist for more tests. These can include:
Special machines are used to scan and create pictures of the inside of your body. You may have an injection of dye into your veins before the scan which makes the pictures clearer.
During the scan you will lie on a table which moves in and out of the scanner. A CT scan takes about 10-30 minutes.
An MRI scan produces detailed cross-sectional pictures of your body and can show the extent of any tumours.
You will lie on a table which slides into a large metal tube that is open at both ends. An MRI scan takes about 30-90 minutes.
Before having the PET scan you will be injected with a small amount of radioactive solutions. You will be asked to sit for 30-90 minutes so the solution can mover around your body. Many cancer cells will show up brighter on the scan. The scan takes around 30 minutes.
Soundwaves are used to create pictures of the inside of your body. You will be asked to lie down and a gel will be spread over the affected part of your body and then a small device (transducer) is moved over the area. The ultrasound takes about 15 minutes and is painless.
If your doctor sees any abnormal or unusual-looking areas they may remove a small sample of the tissue for closer examination. This is known as a biopsy. A pathologist will look at the sample under a microscope to check for signs of disease or cancer.
Treatment for adenoid cystic carcinoma
You will be cared for by a multi-disciplinary team of health professionals during your treatment for ACC.
Discussion with your doctor will help you decide on the best treatment for your cancer depending on where it is in your body; whether or not the cancer has spread; your age, fitness and general health and your preferences.
The main treatments include surgery, radiation therapy and chemotherapy which can be given alone or in combination.
Surgery is usually the most effective treatment for ACC if the cancer can be safely removed. Surgery usually involves removing the cancer and some healthy tissue around the cancer. This is called a wide local excision. The healthy tissue is removed to help reduce the risk of the cancer coming back in that area.
The surgeon will examine nearby nerves and lymph nodes and may remove them if they are involved. It can be a difficult decision to remove nerves, especially major nerves or those that control the face.
Radiation therapy (radiotherapy)
Radiation therapy (also known as radiotherapy) uses high energy rays to destroy cancer cells. It may be used effectively for ACC after surgery, to destroy any remaining cancer cells and stop the cancer coming back.
It might also be used alone if surgery is not possible, for example:
- if the cancer is in a place in the body that is too hard to reach using surgery
- if the cancer has spread to other parts of the body (e.g. palliative radiation for the management of pain).
Chemotherapy (sometimes just called “chemo”) is the use of drugs to kill or slow the growth of cancer cells. You may have one chemotherapy drug, or a combination of drugs. This is because different drugs can destroy or shrink cancer cells in different ways.
Chemotherapy is not commonly used for ACC. It may be considered when the cancer is advanced as part of palliative treatment or as part of a clinical trial. Your medical oncologist will discuss options with you.
In some cases of ACC, your medical team may talk to you about palliative care. Palliative care aims to improve your quality of life by alleviating symptoms of cancer.
As well as slowing the spread of ACC, palliative treatment can relieve pain and help manage other symptoms. Treatment may include radiotherapy, chemotherapy or other drug therapies.
Treatment TeamDepending on your treatment, your treatment team may consist of a number of different health professionals, such as:
- GP (General Practitioner)- looks after your general health and works with your specialists to coordinate treatment.
- Surgeon- surgically removes tumours and performs some biopsies.
- Radiation oncologist- prescribes and coordinates radiation therapy treatment.
- Medical oncologist- prescribes and coordinates the course of chemotherapy.
- Cancer nurses- assist with treatment and provide information and support throughout your treatment.
- Speech pathologist- helps with swallowing and communication difficulties during and after treatment.
- Dietitian- recommends an eating plan to follow while you are in treatment and recovery.
- Other allied health professionals- such as social workers, pharmacists and counsellors..
Screening for adenoid cystic carcinoma
There is currently no national screening program for ACC available in Australia.
Preventing adenoid cystic carcinoma
As the causes of most ACCs are not understood there is no prevention advice specific to this disease.
Prognosis of adenoid cystic carcinoma
It is not possible for a doctor to predict the exact course of a disease, as it will depend on each person's individual circumstances. However, your doctor may give you a prognosis - the likely outcome of the disease - based on the test results, the rate of tumour growth, as well as your age, fitness and medical history.
Understanding Adenoid Cystic Carcinoma. Cancer Council Australia © 2021. Last medical review of source booklet: February 2021.
Australian Institute of Health and Welfare (AIHW). Cancer in Australia 2019. Cancer series no.119. Cat. no. CAN 123. AIHW, Canberra, 2019.
This web-based resource was made possible by the Cancer Australia Supporting people with cancer Grant initiative, funded by the Australian Government.