Recent studies have tied the human papillomavirus, or HPV, to oropharyngeal squamous cell carcinoma.
by Wendy S. Hupp, DMD
There are few things new to the arena of oral cancer. We’re still not catching the tumors early enough for a good overall prognosis; people are still using tobacco; treatment still has large effects on the region, such as xerostomia, fibrosis of tissues, and disfigurement. But let’s look at some of the innovations that should help future patients have a longer and better quality of life after diagnosis.
Research
During the past few years, many researchers have postulated that there are viruses associated with oral cancer. Recent studies have actually tied the human papillomavirus, or HPV, to oropharyngeal squamous cell carcinoma. There are relatively new techniques, such as the polymerase chain reaction, or PCR, that take a tiny amount of DNA and magnify it to confirm the presence of the specific strains of HPV. One study just published1 actually shows that a subgroup of these tumors, nonkeratinizing carcinoma, or NKCa, was different from the keratinized tumors in that the NKCa had HPV in 100 percent compared to only 20 percent of the keratinized tumors. Furthermore, with immunohistochemical staining, these researchers showed that HPV 16 was present in as many as 90 percent of oropharyngeal cancers. While this study involved a small number of patients, it bears consideration for future diagnostic testing.
Diagnostic testing
A new gadget called a Visually Enhanced Lesion Scope (VELScope) was recently developed.The hand-held device shines a blue-colored light into the mouth that causes certain molecules in cells to fluoresce. Normal, healthy tissue appears with a pale green fluorescence, while dysplastic or early tumor cells appear dark green to black. In one study, the investigators evaluated 50 tissue sites from 44 people. All sites were biopsied, and pathologists classified seven as normal, 11 with severe dysplasia, and 33 biopsies were oral squamous cell carcinoma. Reading the fluorescence patterns of the 50 sites, the group correctly identified all of the normal biopsies, 10 of the severe dysplasias, and all of the cancers. These numbers translated to 100 percent specificity and 98 percent sensitivity. Sensitivity refers to how well a test correctly identifies people who have a disease, while specificity characterizes the ability of a test to correctly identify those who are well.
The next step is to evaluate the VELScope in a larger group. Other areas are also being studied with this technology, such as lung and cervical cancers.
The use of the VELScope might provide the biological basis whether to biopsy or not. Early detection leads to a better prognosis, and this technique is quick and painless. Clinical judgment on the look of a lesion will be assisted by this simple test. Looks can be deceiving.
Another recent addition to the oral-cancer diagnostic tools list is the Vizilite. This product was introduced to dentists by Zila Pharmaceuticals (Phoenix, Ariz.) to assist in the early diagnosis of oral cancer and potentially malignant areas in the mouth. It follows similar products used by OB/GYN physicians and consists of a plastic chemiluminescent light stick, a retractor/carrier for the light stick, and a solution containing 1 percent acetic acid. Normal mucosa absorbs the light, but premalignant and malignant lesions reflect the light, therefore appearing white.
Patients rinse with the solution for about one minute (it has a pleasant berry flavor to cover the vinegar taste). The light stick is activated by bending it slightly to crack the internal capsule, then shaking gently to allow the chemicals to mix. The reaction produces a blue-white light that lasts for about 10 minutes. With the room lights dimmed, the intraoral examination is facilitated with the light from the stick that has been placed in the carrier. Areas that appear white under this light are considered suspicious and should be biopsied. In one small study2, Vizilite showed better than 80 percent accuracy and no false negatives. Further studies are planned for a larger group of patients. Vizilite might be helpful in detecting early lesions, especially in high-risk patients.
Tobacco cessation
I’ve been an advocate of tobacco cessation for many years. (Please see the February 2004 WDJ article “STOP! Smoking.”3) Women have made huge advances in our use of tobacco during the past 50 years. Oral cancer has made similar advances. In 1950, there were six oral cancers in men for each woman. Today, the incidence is two to one. It’s suspected that these trends are connected. The best advice for patients of either sex is don’t start using tobacco, and if you are using, stop. (See box.)
Please look
What part of comprehensive oral examination isn’t understood? We teach and learn that an oral-cancer screening exam is part of a comprehensive oral examination, but many dentists stop doing it. Why? It takes a few minutes and could save a life.
Statistics are boring, but let’s look at some scary ones. Approximately half of patients diagnosed with oral cancer will not be alive in five years. This rate has not changed in more than 40 years. We must catch these cancers earlier. About 75 percent of dentists report that they are doing cancer screenings on all patients, yet only 50 percent of patients are aware of it. Make sure that you tell your patients what you are doing. About 30,000 Americans will be diagnosed with oral cancer this year, and about 8,000 will die of this disease. The earlier the diagnosis, the better the prognosis.
When polled, a large percentage of dentists said that they don’t do the oral-cancer screening because they don’t get paid for it. I say it’s time to remember that there’s a person attached to those crowns. Do the exam while you’re waiting for anesthesia to take effect. Include the exam during annual checkups or more often for high-risk patients such as tobacco users. Three minutes or less of your time is all that is needed for most patients.
Cool Web site
Recently, the founder of the Oral Cancer Foundation spoke during the American Academy of Oral Medicine annual meeting. I was touched by a presentation by Brian Hill, an oral cancer survivor. His story is becoming more typical. He was diagnosed with a late-stage tumor and had never been a smoker. In fact, he had been seen by at least two dentists within a year prior to his diagnosis. He survived the treatment and has developed a Web site, www.oralcancerfoundation.org. There are resources for everyone involved with oral cancer and public service announcements against tobacco.
Hill’s goal is to make oral cancer as well known as other cancers in the United States. Women are good at getting pap smears and mammograms. Men are getting their PSA checked regularly. Now there are TV commercials about HPV. Oral cancer could be next. Even if all dentists are examining all patients, it’s still up to patients to seek the professional opinions we can provide. Consider yourself one of the players on this team, and make your patients aware of the oral cancer screening exam. You could save a life.
References:
1 El-Mofty SK, Patil S. Human papillomavirus (HPV)-related oropharyngeal nonkeratinizing squamous cell carcinoma; characterization of a distinct phenotype. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2006;101:339-45.
2 Ram S, Siar, CH. Chemiluminescence as a diagnostic aid in the detection of oral cancer and potentially malignant epithelial lesions. Int. J. Oral Maxillofac. Surg. 2005; 34: 521-527.
3 Hupp WS. STOP! Smoking. WDJ 2004;2(2):34-37.
Wendy S. Hupp, DMD
Dr. Hupp is an assistant professor of oral medicine, College of Dental Medicine at Nova Southeastern University in Fort Lauderdale, Fla. An AAWD member since 1985, she is a founding member of the editorial board of WDJ. Reach her at [email protected].
Tobacco cessation resources
Web sites -
Many Web sites are available to help patients in tobacco cessation:
• The American Lung Association (www.lungusa.org) also provides a search by zip code for local support groups.
• The National Cancer Institute, (800) 4-CANCER or www.nci.nih.gov, has a free, illustrated pamphlet for dental health care providers titled “Tobacco Effects in the Mouth.” This pamphlet has pictures of how to do a cancer-screening exam as well as clinical changes from tobacco use that can be shown to your patients.
• The American Cancer Society (www.cancer.org) and Centers for Disease Control Office on Smoking and Health (www.cdc.gov/ tobacco) are helpful resources for cessation strategies and free support plans.
Pharmaceutical products -
Several pharmaceutical products also provide resources, from booklets to money-back coupons and Web sites.
• GlaxoSmithKline has a nicotine patch (www.nicodermCQ. com), chewing gum (www.nicorette.com), and a smoking-cessation program (www.committedquitters.com).
• The Commit Lozenge, also from GlaxoSmithKline, is discussed at www.commitlozenge.com and supported by quit.com, an interactive Web site.
• Pfizer, Inc. makes Nicotrol patches and provides guidelines at www.pfizer.com.
