• 10/7/2007
  • Los Angeles, CA
  • staff
  • TradingMarkets.com

The cancer that killed Steven Moore, chairman and chief executive of OGE Energy Corp., is rare. Moore succumbed to parotid cancer — a cancer of the salivary glands — after an eight-year battle.

Salivary gland cancers encompass more than 10 types of tumors, some of which are fast-growing and some of which may never threaten a person’s life. Moore’s cancer was in his parotid glands, the largest of the salivary glands. The parotid glands are found in the cheeks on both sides of the face, just in front of the ears. Most salivary gland tumors originate in the parotid glands, according to the American Cancer Society.

“Most of these tumors have poor survival, and one of the reasons is probably the fact that we don’t know enough about them,” said Dr. Lurdes Queimado, an assistant professor at the University of Oklahoma Health Sciences Center and holder of the Presbyterian Health Foundation chair in otorhinolaryngology. Queimado is an ear, nose and throat doctor.

The National Cancer Institute estimates there are about three cases of salivary gland cancer per 100,000 people. The cases represent 3 to 5 percent of all head and neck cancers.

Treatment challenging

Queimado said cancer could sprout most anywhere.

“On the one end, they (salivary gland cancers) are rare,” she said. “On the other end, the histology is very variable,” she said of the tumors’ appearances, which makes diagnosis and treatment challenging.

Salivary gland tumors typically are benign. Some benign tumors become cancerous years later, making removal the common treatment.

Tumors also may originate in the submandibular and sublingual glands, which are smaller than the parotid glands and are found, respectively, on either side of the neck, under the chin and tongue area; or under the floor of the mouth, below either side of the tongue.

The head has 600 to 1,000 minor salivary glands that are too small to be seen without a microscope. Tumors that start in these glands are most likely to be cancerous. Approximately one-quarter of parotid gland tumors are malignant.

Increasingly common

Queimado said salivary gland cancer had become more common in the past two decades, and researchers aren’t sure why. Doctors and dentists typically discover the tumors during routine exams. She said salivary gland tumors were biologically different than other cancers.

In trying to determine a cellular “marker” that is unique to salivary gland cancers, Queimado and other OUHSC researchers discovered a certain protein is present at low levels in tumors that later become cancerous and not present in those that are cancerous.

When she added the protein, normal cells were unaffected, but cancer cells were killed. She has applied for a grant from the National Institutes of Health to move from tissue samples to trying the method in mice. She has published her findings several times since 1998. She has been researching salivary gland cancer since 1991.

“We really think this is going to work,” she said of the research’s potential for treatment.

Common treatment

Dr. Keith Clark, an ear, nose and throat surgeon with St. Anthony Hospital, said patients showed up with lumps in their glands that often weren’t painful. If the tumor has grown into nearby nerves, facial movement can be affected.

Doctors often can perform a fine needle aspiration, a procedure in which they take a small sample of a tumor to examine under a microscope to determine if it’s cancerous.

However, blockages of gland ducts can cause discomfort, inflammation and tumor-like symptoms. When this is the case, Clark is able to use a tiny camera to see the blockage and a wire tool to remove it.

Removal of the parotid glands is difficult and poses risks to the patient, he said. To remove the glands, surgeons must dissect branches of the facial nerves that pass through the gland.

“It’s no small matter to be taking out the parotid gland,” he said.