Treatments for Adenoid Cystic Carcinoma

Executive Summary:

Adenoid Cystic Carcinoma mainly affects the salivary glands. Regardless of where it begins, it tends to metastasize along the nerves. A multidisciplinary approach helps in treating any ACC. The treatment involves including different types of doctors and other healthcare members. The primary goal of cancer treatment is not just to eliminate cancer or tumor but also to preserve the functioning of nearby organs, nerves and tissues. Treatment options and plans are based on several factors like the type of adenocarcinoma, its stage and grade, probable side effects, the patient’s preferences, choices and overall health condition.

Patients should take time to learn about all the available treatment options and be sure to ask questions and clear doubts about things that are unclear and appears complex. Some common treatments for ACC include surgery, radiation therapy (external beam, neutron, and proton radiation therapy), systemic therapy (chemotherapy and targeted therapy), palliative care, and follow-up care for any remission of ACC.

Adenoid Cystic Carcinoma

Adenoid cystic carcinoma (ACC) is a rare but malignant form of adenocarcinoma. ACC is a broad term that describes any cancerous growth or tumor that begins in the epithelial tissues. Neck and head region is the most common form of Adenoid Cystic Carcinoma. But it can also develop in other parts of the body like the uterus, breast, lungs, lacrimal gland of the eye, brain, sweat glands, trachea and the Bartholin gland. Adenoid Cystic Carcinoma mainly affects the salivary glands. The salivary gland comprises cell clusters that secrete saliva throughout the upper aerodigestive tract. The upper aerodigestive tract encompasses tissues and organs of the upper respiratory tract like the mouth, lips, tongue, throat, vocal cords, nose, a part of the esophagus and the windpipe.

The Salivary glands can be divided into two groups based on their size- minor salivary glands and major salivary glands. A cancerous growth or tumor can begin in any part of the minor or major salivary glands. 

Minor salivary glands

• Palate: It refers to the roof of the mouth (hard palate and soft palate)
• Tongue base: It refers to the bottom or back third of the tongue
•  Nasopharynx: An air passageway is present at the upper part of the throat and behind the nose.
• Larynx: It is the voice box.
• The mucosal lining of the mouth: It refers to the inner lining of the mouth. It has glands that secrete mucus.
• Trachea: It is the windpipe

Major salivary glands

• Sublingual glands: These are glands located under the tongue in the mouth.
• Parotid glands: These are the largest salivary gland. It can be on either side of the face in front of each ear.
• Submandibular glands: Jawbone has these glands.
• Regardless of where it begins, Adenoid Cystic carcinoma tends to metastasize along the nerves. This type of invasion is termed perineural invasion. Sometimes the invasion and metastasis happen via the bloodstream. In 5-10% of cases, the tumor spreads to the lymph nodes. ACC becomes metastatic Cancer when it spreads to distant body parts beyond the lymph nodes. The commonplace where ACC extends is into the lungs. Adenoid Cystic Carcinoma grows at a languid pace. It remains inactive or without growth for long periods, followed by a sudden burst of growth. The tumor can be aggressive and highly invasive in some people, making their disease condition difficult and unpredictable.

Adenoid Cystic Carcinoma is of three types based on their appearance under a microscope. They can be classified as 

• Cylindroma is a cancerous growth with tube-shaped cells.
• Cribriform is a tumor whose appearance is similar to that of Swiss cheese. These tumors have gaps between the cells. 
• Solid Adenoid Cystic Carcinoma (ACC).

Treatments Plan for Adenoid cystic carcinoma

A multidisciplinary approach helps cancer treatment. The treatment will include the involvement of different doctors and other healthcare members (called the multidisciplinary team) and will use different treatment strategies for Adenoid cystic carcinoma.

The health care team will include the following specialists:

• Medical oncologist is a doctor who specializes in using medication to treat Cancer. 
• Surgical oncologist is a doctor specializing in and performing surgery to treat Cancer. 
• A radiation oncologist is a doctor who uses radiation therapy to treat and destroy cancerous growth.
• Otolaryngologist is a doctor specializing in the nose, ear, and throat.
• Maxillofacial prosthodontist is a specialist who performs restorative surgery in the neck and head regions. 
• Reconstructive or Plastic surgeon is a surgeon who specializes in reconstructing facial and body tissues, thereby improving a person’s appearance
• An oral oncologist or Oncologic dentist are dentists specializing and experienced in treating and caring for people with neck and head cancer.
• A physical therapist is a health professional or therapist who addresses functional or operational challenges that may develop in a patient due to cancer diagnosis and treatment.
• An audiologist is a health professional specializing in hearing and balance problems. 
• A speech pathologist is a specialist or health professional who helps patients use the throat and mouth muscles.
• Mental health providers are health professionals such as psychologists or psychiatrists who diagnose and treat patients’ mental health issues. Besides these people, cancer care includes a variety of other health care professionals like nurse practitioners, oncology nurses, physician assistants, dietitians, pharmacists, social workers, and many more others. All these people come together to devise a treatment plan as suiting the patient’s cancer condition. The team will design a comprehensive treatment plan by evaluating the patient’s disease condition and overall health.

Goal of cancer treatment

The primary goal of cancer treatment is not just to eliminate cancer or tumor but also to preserve the functioning of nearby organs, nerves and tissues. While planning the treatments strategy for Adenoid cystic carcinoma, doctors will consider how it might affect the quality and comfort of a person’s life. The standard treatment techniques used to treat Adenoid Cystic Carcinoma are surgery, radiation therapy, and various systemic therapies (chemotherapy, targeted therapy) using medication ^​1​. The treatment plan will also focus on managing and relieving symptoms, signs and side effects, which forms an essential part of cancer treatment.

Treatment options and plans

Treatment options and plans are based on several factors like the type of adenocarcinoma, its stage and grade, probable side effects, the patient’s preferences, choices and overall health condition. Patients should take time to learn about all the available treatment options and be sure to ask questions and clear doubts about things that are unclear and appears complex. Ask your doctor about the aim of each treatment and what outcome you can expect while receiving the treatment. It will help the healthcare team choose and plan a treatments strategy for Adenoid Cystic Carcinoma that best fits your aims and expectations.

Surgery for Adenoid Cystic Carcinoma

A surgery is a procedure where the tumor and some surrounding healthy tissues are removed via an operation. Surgery is one of the best treatments for Adenoid Cystic Carcinoma. The surgeon will remove the tumor and a margin during a surgical procedure, which refers to the healthy tissue surrounding the tumor. The surgical procedure will vary depending upon the tumor stage, its location and the body part it has affected.

Since Adenoid Cystic Carcinoma can spread along the nerves, the surgeon will examine for that. If any significant nerves are identified as involved in cancer spread, they are spared during surgery. The smaller branches are closely analyzed to see whether the cancerous growth has spread to the nerve area. In the case of an advanced ACC tumor or one that involves large parts of nerves, the surgeon will try to remove the tumor as much as possible while sparing the facial features and their functions. Ask your doctor about finding a experienced and qualified surgeon to perform such surgical procedures.

Side effects of surgery

Surgical procedures will cause some side effects, and this depends upon the site of the surgery. For instance, if a surgical procedure is carried out on the parotid salivary gland, the method will likely damage the facial nerves, which can cause the facial muscles to droop. Sometimes, a reconstructive procedure (like plastic surgery) or a facial nerve graft is recommended to restore the facial muscle functions after a tumor removal surgery. The patients need to talk with their health care team about the probable side effects of treatment. They should enquire whether they would require any reconstructive surgery or not. 

Adenoid Cystic Carcinoma is called an inoperable tumor. Hence surgical procedures may not be enough to eradicate the cancer growth. Some additional treatment options may be needed, called adjuvant therapy. The doctor will recommend other treatment options, like radiation therapy or therapies assisted with medications. 

Radiation Therapy

External-beam radiation therapy for Adenoid Cystic Carcinoma

Radiation therapy refers to high-energy x-rays or other particles to destroy cancerous growth. External-beam radiation therapy is the most common type of radiation therapy. In this, the radiation is given from a machine outside the body. A radiation therapy schedule or regimen consists of treatment strategies for Adenoid cystic carcinoma administered to the patient ^​2​.

Radiation therapy effectively treats ACC as adjuvant therapy by eliminating any microscopic cancer growth or cells that may remain in the body after the surgical procedure. Adjuvant therapy refers to the treatment that is given post-surgical process. In the case of ACC, radiation therapy is not given before surgery (preoperatively) as surgeons feel that surgical wounds heal better when no therapy is administered before surgery. 

Side effect of radiation therapy

In external-beam radiation therapy, intensity-modulated radiation therapy (IMRT) permits effective doses of radiation therapy to the patient while reducing the damage caused to the healthy cells, thereby limiting the treatment side effects. The side effects of radiation therapy depend on the area targeted for therapy since the therapy targets a specific location. The general side effects that patients may face during a neck and head treatment are sore throat or mouth that can cause extreme pain and difficulty swallowing. The medicine can also cause skin burn or reaction and hence more pain over time.

Side effects of radiation therapy

Patients about to receive radiation therapy as part of any head and neck cancer treatment are advised to consult an oncologic dentist and conduct a thorough examination. Radiation therapy can cause tooth decay, and damaged teeth should be removed. Patients should consult a dentist and get proper treatment before the radiation therapy begins to avoid tooth decay. Patients seeking treatment for any head and neck cancer are also advised to consult an experienced speech pathologist. A speech pathologist can teach exercises to help a patient maintain flexibility and strength of the muscles used for swallowing and speech. If the treatment plan is causing side effects that affect a person’s nutrition and health, then consulting a registered dietitian nutritionist (RDN) is also recommended.

The long-term side effects of radiation therapy include permanent loss of saliva, which can cause mouth dryness and decay and deterioration of teeth. In some cases, a drug that can stimulate the parotid salivary gland or restore the saliva levels may be given to the patient. Fibrosis or scarring, which refers to the thickening of the skin and muscles, may occur in patients several months or years after radiation therapy. It can cause a delay in wound healing, trouble swallowing and stiffness in the neck region. Rapid narrowing of the carotid arteries, which supplies blood to the neck and head region, is another long-term side effect of radiation therapy. Radiation therapy can also cause hypothyroidism or lower thyroid gland functioning, managed with a thyroid hormone replacement medication. Amifostine (Ethyol) is a drug that is currently being studied to be used to protect tissues during radiation therapy.

Neutron radiation therapy for Adenoid Cystic Carcinoma

Neutron radiation therapy is a form of radiation therapy that uses neutrons instead of X-rays. This therapy’s efficiency is high compared to the conventional radiation therapy mode, as neutrons can deliver about 20-100 times more energy along their path length, thereby causing more damage to and efficiently destroying the cancer cells.

Side effects of neutron radiation therapy

Neutron radiation therapy is the preferred mode for treating ACC, mainly if the tumor is present in such a part of the body where it is tedious or impossible to perform a surgical procedure ^​3​. But neutron radiation therapy can cause more side effects than traditional radiational therapy. It can cause severe soreness in the throat or mouth and swallowing difficulties. Therefore, this mode of radiation therapy is good in the case of people who have an inoperable or recurring tumor. Drugs and medications may help increase saliva production and protect healthy tissues during neutron assisted radiation therapy. This therapy is not good for vast areas of treatment of the body or metastatic cancers. But they are effective against an isolated metastasis that is causing troubles, such as extreme pain, pressure on the spinal cord.

Proton radiation therapy for Adenoid Cystic Carcinoma

Proton radiation therapy is also called proton beam therapy. It is a form of external-beam radiation therapy that uses protons instead of x-rays. At high energy, protons can efficiently destroy cancer cells or tumors. The advantage of proton therapy is that it effectively eliminates the targeted tumor by causing very little damage to the nearby normal healthy tissues and cells. However, proton radiation therapy has not been extensively studied or researched to prove its effectiveness in treating Adenoid Cystic Carcinoma. 

Neutron and proton radiation therapy are not widely available. Ask your doctor about the availability of these treatments for Adenoid Cystic Carcinoma if they are recommended for your disease condition.

Systemic therapy (Therapies using medication)

Systemic therapy refers to medication or drugs to eliminate cancer cells. These drugs or medicines reach tumor growths or cells through the bloodstream throughout the body. A medical oncologist usually prescribes such therapies. Systemic therapies are commonly given in two ways:

• Using an intravenous (IV) tube to administer medication into the vein using a needle.
• In an oral capsule or pill form.
• The systemic therapies used to treat Adenoid Cystic Carcinoma (ACC)

The systemic therapies used to treat Adenoid Cystic Carcinoma (ACC) are Chemotherapy and Targeted Therapy ^​4,5​. A patient may receive one of these, or sometimes a combination of both, administered simultaneously. Systemic therapies can also be given as part of the overall treatment plan, including surgery or radiation.

Many studies focus on developing efficient medications that can help treat and cure cancer. Patients should talk with their doctor about the prescribed medicines and learn and understand more about them. Ask them questions regarding the purpose, possible side effects of the drugs, and their possible interactions with other treatments for Adenoid Cystic Carcinoma and medications. One should also let their doctor know about any additional treatment or medicines they are taking well before cancer treatment. Certain drugs herbs can interact with cancer medications and can cause complications.

Chemotherapy for Adenoid Cystic Carcinoma

Chemotherapy or chemo procedure refers to drugs or medications to eliminate cancer cells. These drugs operate by preventing the cancer cells from growing, dividing and generating more cells. A chemo regimen generally consists of several cycles given over some time. A patient may receive a single type of drug or a combination of different medications, all given simultaneously.

In the case of Adenoid Cystic Carcinoma, chemotherapy is less effective, as these tumors appear less responsive to chemo drugs. Different combinations of drugs has not shown much success in trial. Many experiments are being carried out to develop procedures to treat Adenoid Cystic Carcinoma. The research analyses the efficiency of combining chemotherapy with radiation therapy to treat ACC. 

Also Read: How To Make Friends With Food During Chemo

Targeted therapy for Adenoid Cystic Carcinoma

Targeted therapy refers to a systemic treatment that targets specific genes, proteins of the cancer cells and the surrounding tissue that contributes to tumor growth and proliferation. This therapy shuns Cancer’s development and metastatic capability by causing very little damage to the surrounding healthy cells. 

The targets of each tumor differ. To choose the suitable treatment options for Adenoid Cystic Carcinoma, the doctor will run various tests or scans to identify the tumor’s proteins, genes, and other characteristic features. It helps the doctor to implement the most effective treatment. Many types of research are happening in this field, too, to devise better target therapy options. For instance, clinical trials are studying the use of targeted therapy medication Tyrosine Kinase Inhibitors (TKIs), such as sorafenib (Nexavar) lenvatinib (Lenvima) for oral medication. It has shown some positive results in treating people with ACC. Adenoid Cystic Carcinoma is a rare form of cancer, and chemo procedures are not effective sometimes, in that case people may inquire about any clinical trials that will help cure the disease. Patients can also seek second opinions regarding ACC treatment options and strategies. 

Palliative Care

Cancer can cause many physical, emotional and social effects. Cancer care doesn’t end with active treatment. Post-treatment care is as critical as active treatment. Palliative or supportive care focuses on managing and relieving symptoms and side effects associated with cancer treatment.

It focuses on improving a patient’s condition by helping them to manage and relieve symptoms. The care extends support not just to the patients but also to their loved ones. It also focuses on the non-medical needs of cancer patients, like managing finances. Palliative care is independent of the age, cancer stage or type of patient. Palliative care works best right after a cancer diagnosis. It helps prevent the cancer condition and its symptoms and side effects from aggravating. Palliative focuses on improving the comfort and quality of a patient’s life. Palliative care enhances the effectiveness of active treatments for Adenoid cystic carcinoma. Sometimes a patient may receive chemotherapy, surgery or radiation therapy as palliative care.  

Patients should talk with their health care team about the aim of each treatment option for Adenoid Cystic Carcinoma, about the probable side effects and the available palliative care options before the active treatment begins.

The health care team will enquire about your medical history, symptoms and side effects during treatments of Adenoid Cystic Carcinoma. Be sure to communicate whatever you are feeling to the doctor. It helps them treat any symptoms or side effects that you are experiencing with ease. It will eventually help prevent your condition from becoming worse. 

Metastasis

Metastatic Cancer refers to cancer or tumor that spreads from its point of origin to different body parts. If you are experiencing any signs or symptoms related to cancer metastasis, communicate it with your doctor. The doctor or the health care team will develop an active treatment plan to cure this condition. One can also go for clinical trial options. 

Metastasis can occur even after active treatment and removal of the cancer growth. Hence it can be stressful for the patient and their loved ones to bear the diagnosis. So, patients and their loved should have active communication with the doctor, nurses, social workers or counsellors regarding how they are feeling. Patients can also talk with other cancer survivors or join a support group.

Remission and the chance of cancer recurrence

Remission refers to a stage where there are no signs or symptoms of cancer in the body. The condition can be called NED or “no evidence of disease” in the body. Remission can be permanent or temporary. Patients must continue tests, scans, physical examinations even after successful treatments for Adenoid Cystic Carcinoma to look for any recurrence. Talk with your doctor about the chance of the cancer condition recurring back in your body. If cancer recurs in the same place as before, it is local recurrence, and if it happens nearby the origin point, it is a regional recurrence. If it recurs in some distant place in the body, it is distant recurrence.

What If the treatment does not work?

Cancer recovery may not be successful at times. The disease condition is advanced or terminal if it is not controlled or cured. Any stage of cancer can be stressful to people. A diagnosis that states an advanced, aggressive tumor can cause even more stress and make people hopeless and uncertain about their lives. Patients should have open, honest communications with their doctor or health care team about their concerns, feelings and preferences. Skilled health care team members will be able to support the patients and their caregivers. They will focus on improving the comfort and quality of the patient’s life by providing them physical, mental and financial support.

People diagnosed with advanced Cancer and the expected chance of survival is for less than six months can consider hospice care. Hospice care focuses on providing the best possible quality care for patients whose survival chance is low. Patients and their families can talk to the health care team about the available hospice options, including a unique hospice centre, hospice care at home or any other health care location. People can also avail nursing care options.

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