Q&A: Ear and Temporal Bone Cancer

Cancer of the ear and temporal bone are rare. They also can be difficult to diagnose and challenging to treat. Yet, progress is being made in discovering what drives these diseases and how to approach them more successfully.

Paul Gidley, M.D., associate professor in the departments of Head and Neck Surgery and Neurosurgery at MD Anderson, answers questions about ear and temporal bone cancers. (See related story on ear cancer patient Scott Goodman.)

What are ear and temporal bone cancers?
Cancers of the ear usually begin as skin cancers on the outer ear, ear canal or skin around the outer ear. The most common types are squamous cell carcinoma and basal cell carcinoma. If they are neglected, they may grow into the:

• Ear canal
• Middle ear
• Mastoid or deep into the temporal bone, which houses the ear canal
• Facial nerve
• Organs for hearing and balance

Squamous cell cancers are the most common type of ear and temporal bone cancers. They tend to be more aggressive and have a higher chance of spreading.

The third most common ear and temporal bone cancer, which is very rare, is adenoid cystic carcinoma. It arises from the glands that produce earwax.
 
Tumors in the parotid gland, the largest salivary gland, also can grow into the ear canal and temporal bone.

Are ear and temporal bone cancers rare?
Yes, they are quite uncommon. It is estimated that about 300 cancers of the ear and temporal bone are diagnosed in the United States each year. More men than women get these types of cancer.

Very few cancer centers have doctors who specialize in ear and temporal bone cancers. At MD Anderson, we see about six cases a year in which the cancer is confined to the patient's ear. We see another 40 or so with cancer around the ear canal, the parotid gland or outside the ear.

What causes ear and temporal bone cancers?
We know that getting too much sun is a risk factor for skin cancer. However, ear and temporal bone cancers are so rare that there aren't really enough cases for us to be able to tick off a list of risk factors. Smoking or family history have not been proven to increase risk.

What are the symptoms of ear and temporal bone cancers?
There are three main symptoms of ear and temporal bone cancers. They are:

• Hearing loss
• Ear pain
• Bleeding or drainage from ear

These symptoms generally are non-specific and can be seen with other illnesses.

Since these cancers often begin as skin cancers, an early sign might be scaly patches or tiny white bumps on the outer ear or in the skin around the ear. If neglected, these tumors can grow to a large size and produce significant symptoms like facial weakness or paralysis.

How are ear and temporal bone cancers diagnosed?
Ear and temporal bone cancers are diagnosed by biopsy of the tumor. Unfortunately, ear canal and temporal bone cancers frequently are misdiagnosed as outer ear infections. Many times, patients are treated with eardrops for a month or two for an ear infection before a definitive diagnosis of cancer is made.

Imaging tests, such as CT (computed tomography) or MRI (magnetic resonance imaging) scans, are necessary to determine the extent of the cancer. They also reveal if it has spread to the parotid gland or lymph nodes in the neck.

What are the main treatments for ear and temporal bone cancers?
The typical treatment is surgery. The goal is to remove the tumor completely. Some common procedures include removal of the:

• Ear canal, eardrum and two of the three small bones in the middle ear. A special implant called a bone-anchored hearing aid (BAHA) can be used to overcome hearing loss caused by the surgery.
• Parotid gland and lymph nodes in the neck. Our colleagues in head and neck surgery help with these procedures.
• Some or all of the outer ear. A soft tissue flap is used to fill in the hole that is created. Our colleagues in plastic and reconstructive surgery help with these procedures. Prosthetic ears can be created, and our colleagues in anaplastology/dental oncology help with these procedures.

Most patients receive radiation therapy after surgery, typically for six weeks or so.