What’s New in Oral Cavity and Oropharyngeal Cancer Research?

Research on oral and oropharyngeal cancers is being done in many university hospitals, medical centers, and other institutions worldwide. Each year, scientists find out more about what causes these diseases, how to prevent them, and how to better treat them.

Most experts agree that treatment in a clinical trial should be considered for any type or stage of cancer in the head and neck areas. This way people can get the best treatment available now and may also get the new treatments that are thought to be even better.

DNA changes in oral cavity and oropharyngeal cancers

A great deal of research is being done to learn about the DNA changes that cause the cells in the oral cavity and oropharynx to become cancer.

In more than half  of all head and neck cancers, the cancer cells have changes (mutations) in the PIK3CA gene. This can cause cells to grow out of control, which can lead to cancer. Drugs that target the protein made by the abnormal PIK3CA gene, called PI3K are already approved to treat some other types of cancer. Studies are now being done to see if similar targeted therapy drugs will work in head and neck cancer, especially HPV-positive cancers, because they tend to have too many copies of the PIK3CA gene. 

One of the changes often found in DNA of oral cavity and oropharyngeal cancer cells, especially HPV-negative cancer cells, is a mutation in the TP53 gene. The protein produced by this gene (called p53) normally helps keep cells from growing too much and helps to destroy cells that are too damaged to be fixed. Changes in the TP53 gene can lead to increased growth of abnormal cells and cancer.

Some studies suggest that tests to find these gene changes might help find oral and oropharyngeal cancers early. These tests may also be used to better find cancer cells that might have been left behind after surgery and to determine which tumors are most likely to respond to chemo or radiation therapy. The use of p53 gene therapy as a treatment for these cancers is also being studied in early-phase clinical trials.

Discoveries about how changes in the DNA of cells in the mouth and throat cause these cells to become cancer are also being applied to experimental treatments intended to reverse these changes. Another type of gene therapy boosts the immune system so it can better find and kill cancer cells. These forms of treatment are still in very early stages of study, so it will be several years before we know if any of them are effective.

Screening and early detection of oral cavity and oropharyngeal cancers

Cancers of the head and neck can be hard to find early. And almost half of all oral cavity and oropharyngeal cancers have already spread to the lymph nodes when they are first diagnosed. Given these issues, research is being done to find ways to detect these cancers more easily and hopefully sooner. For example, some researchers are testing the air people breathe out (exhale) for certain chemicals that seem to be linked with cancer of the head and neck area.

Looking for HPV infection has become a part of screening tests for cervical cancer over the years. Given the rise in HPV-positive head and neck cancers, especially in the oropharynx, some studies are looking at ways to screen for HPV infection in the oral cavity and oropharynx. However, there are currently no tests approved by the Food and Drug Administration (FDA) for this. Other studies are checking to see if blood tests might identify people infected with the high-risk types of HPV, and if this is something that can be used to screen for HPV-positive oropharyngeal cancer. This might help prevent or catch these cancers early.

Researchers are also developing other types of tests to help find these cancers early. For example, in one test that can be done at home (known as CancerDetect), you collect a sample of saliva and mail it to a lab. The cells in the sample are then tested for genetic changes that are linked to cancer. While this test is available for purchase, it is not part of the screening recommendations from expert groups at this time. More research will be needed to show how well it works before it can be approved by the FDA.

Treatment of oral cavity and oropharyngeal cancers

Oral cavity and oropharyngeal cancers that are linked with HPV tend to have a better outcome than those that are HPV-negative. Clinical trials are starting to look at these HPV-positive and HPV-negative cancers separately. For instance, studies are being done to see if HPV-positive cancers can be treated with less chemotherapy and/or radiation without reducing survival. Researchers are also working on treatments aimed at HPV infections or that target HPV-infected cancer cells. Studies are also looking for better ways to treat HPV-negative cancers, too, as well as the best ways to use the treatments we already have.

A great deal of research is focused on improving results from chemotherapy (chemo) for people with these cancers. This includes figuring out which combinations of drugs work best and determining how best to use these drugs along with other forms of treatment. Researchers also continue to develop new chemo drugs that might be more effective against advanced oral and oropharyngeal cancers. They're also looking at whether drugs approved to treat other types of cancer might work for these cancers.

Doctors are always looking at newer ways of focusing radiation on tumors more precisely to help them get more radiation to the tumor while limiting side effects to nearby areas. This is especially important for head and neck tumors like oral cavity and oropharyngeal cancers, where there are often many important structures very close to the tumor.

Clinical trials are studying targeted drug therapies that might block the action of substances (such as growth factors and growth factor receptors) that cause head and neck cancers to grow and spread. Some targeted drugs are being studied that block the ability of the cancer cell to keep growing and help chemoradiation work better.