Written by Jo-Anne Jones, RDH Wednesday, 31 March 2010 19:00
If you or a loved one has ever been the recipient of a medical diagnosis that leaves your life hanging in the balance, you can fully appreciate how devastating a diagnosis of oral cancer can be. If you have been fortunate and dodged the bullet thus far, take the time to become familiar with alarming new trends and the emergence of an atypical profile for an oral cancer victim that you, as a dental professional, cannot afford to ignore. The omission of the performance of a thorough visual and tactile extraoral and intraoral examination may result in a costly error: the life of a fellow human being. The risk of omission can also come with another cost: legal proceedings and practice breakdown.
The mounting body of evidence collected over the last couple of years has led to a dire need to elevate awareness of oral cancer within the health professional network and particularly within the dental community. There is no other member of the professional healthcare community who possesses a better opportunity to make a positive impact on oral cancer than the dental community. Knowledge gaps both in education and clinical practice on the part of the healthcare professional have contributed to late stage diagnosis, wohich unfortunately has often resulted in fatalities and increased morbidity.
CURRENT ORAL CANCER STATISTICS
Oral cancer strikes more than 34,000 Americans each year.1 It will cause more than 8,000 deaths, killing roughly one person per hour, 24 hours per day.2 Oral cancer is the sixth most common cancer worldwide, with an anticipated yearly incidence of more than 400,0003 with the prevalence being particularly high among men.4 On average, only slightly more than half of those diagnosed with the disease will survive more than 5 years. The mortality rate for oral cancer is higher than many of cancers which we hear about routinely, such as cervical cancer, Hodgkin’s lymphoma, laryngeal cancer, cancer of the testes, endocrine system, cancers such as thyroid, or the skin cancer referred to as malignant melanoma.2
Unfortunately, at this time, detection of oral cancer is occurring too late, with approximately 65% to 75% of oral cancer lesions not identified during a visual examination until stages III or IV.5 Oral cancer 5-year survival is poor, similar to colorectal cancer at 62% and significantly lower than for cervical cancer and breast cancer.6 Those who do survive have not emerged unscathed, having withstood the rigors and painful outcomes of radiation, chemotherapy, and disfiguring surgery. Oral cancer often goes undetected by the patient because in its early stages, it may be symptom-free.
ALARMING NEW TRENDS RELATED TO ORAL CANCER
It is well known that oral cancer is strongly associated with tobacco and alcohol consumption; however, where it once contributed to more than 75% of newly diagnosed oral cancer cases, it is being challenged by a new viral origin of almost equal proportion, according to reporting from major cancer centers.
The medical and dental professional communities have been alerted to alarming new trends regarding oral cancer. It is suggested that the North American population is increasingly at risk for oral cancer due in part to extremely low awareness levels on risk factors, contributing lifestyle behaviors, and prevention. Where we once felt confident to be able to identify the segment of our patient population that may be at increased risk for oral cancer, changing demographics are creating a paradigm shift in our traditional oral cancer risk profiling. No longer can we classify the older male patient with a chronic history of tobacco and alcohol abuse as being the only one at increased risk for oral cancer. Oral cancers are occurring in young adults with no associated traditional risk factors at a rapidly increasing rate.
The culprit is the rapid spread of the human papilloma virus (HPV) through sexual transmission. Recent data has confirmed that HPV-related oral cancer is now the fastest growing segment of the oral cancer population in patients under the age of 50 years not possessing the typical historical risk factors.7 This would indicate a paradigm shift not only in our assessment of high-risk patients but also in the cause of the disease, and in the locations where it most frequently occurs in the oral environment.
There are more than 120 strains of HPV. Most are thought to be harmless, with differences in genetic material within the virus differentiating its properties. There are only a few viral strains that are identified as high-risk for oral cancer; primarily HPV 16 and HPV 18. More than 90% of HPV-positive oral cancers are HPV-16 positive.7 This is the same virus that is the causative agent in more than 95% of all cervical cancers. The proportion of HPV DNA-positive tonsil tumors increased from 28% in the 1970s to 68% in the 2000s, suggesting a dominant role for HPV in the increasing incidence of oropharyngeal cancers.8
It is likely that the changes in sexual behaviors of young adults over the last few decades—which are continuing today—are increasing the spread of HPV, and the oncogenic versions of it. How prevalent is the HPV sexually transmitted virus in our population? Let’s take a look at some sobering statistics:
- HPV is one of the most common sexually transmitted diseases (STDs) in the world
- The US Centers for Disease Control and Prevention estimates close to 5.5 million new genital HPV cases occur each year
- It is estimated that more than 24 million people in the United States are infected with HPV at any given time
- Canadian studies estimate that 40% to 80% of women in their early reproductive years have been infected with one of the more than 80 varieties of sexually transmitted HPV
- Specifically in the United States, nearly 3 out of 4 Americans between the ages of 15 and 49 years have been infected with genital HPV in their lifetimes
- A recent study conducted by the Kaiser Family Foundation found that 70% of Americans knew nothing about the existence of HPV as a STD.7
The most dangerous aspect for at least 9 versions of the HPV is its potential to cause cancer. Those strains of the virus can contribute to the development of dysplasia. Dysplasia on its own is not cancer, but it is a precursor tissue change prior to malignancy. It is reported that HPV associated oral carcinoma occurs in a higher proportion of men, at a younger age and at a more advanced stage than non-HPV associated oral carcinoma, and that HPV oral carcinomas are believed to have a better prognosis in comparison to other oral carcinomas of different etiologies.9 In the long run, this may mean that treatments for HPV positive oral cancers may eventually be administered differently than they are today. At the current time, even though we know that the HPV positive disease has better long-term outcomes after treatments, these patients still had to undergo the same levels of radiation and chemotherapy.
HPV 16 and HPV 18 manifest themselves primarily in the posterior areas of the oral cavity. HPV-related positive oral cancers appear to occur on the tonsillar area (including the tonsillar pillars and crypt as well as the tonsils themselves), the base of the tongue and the oropharynx, while non-HPV positive tumors tend to involve the anterior tongue, the floor of the mouth, and the mucosa that covers the inside of the cheeks and alveolar ridges.
A new vaccine, Gardasil, was developed and promoted to target 4 strains of the human papilloma virus, namely 6, 11 (causing 90% of genital warts), 16, and 18 (related to the majority of cervical cancer cases). In September of 2009, the US Food and Drug Administration (FDA) voted to recommend approval of the vaccination for males aged 9 to 26 years to help further prevent transmission. Gardasil already has Health Canada and FDA approval for use in females ages 9 to 26 years, primarily for the prevention of cervical cancer. Recently, a new vaccine, Cervarix, has been released into the market by GlaxoSmithKline to compete with Gardasil.
WHO SHOULD BE SCREENED
It is clear that the ease of transmission of this virus has become an issue. Certain sexual behaviors, even a seemingly nonsuspect activity as deep kissing (ie, French kissing) can transfer the disease in people who have an oral infection, thus continuing to place an increased number of the population at risk for oral cancer at an earlier age. Opinions differ as to what segment of the population should be screened for oral cancer. The incidence of oral cancer increases with age; however, not screening adults under the age of 40 years means that cases of oral cancer in this younger age profile may go undetected until in the later stages. In addition, targeting those within our practice populations who possess the traditional behavioral risk factors, such as smoking and alcohol use, will defeat the purpose of employing opportunistic screening, resulting in earlier discovery and improved survival rates. Basically, every patient who is old enough to have been sexually active should receive a complete and thorough extraoral and intraoral examination as part of the assessment process at his or her initial new patient appointment, as well as at each recare appointment.
Our dental patients should be encouraged to conduct a self-examination of their heads and necks, as well as intraoral structures at regular intervals. This activity in itself will assist aiding in earlier discovery of an abnormal mucosal or extraoral finding. Patients should be instructed to watch out for any of the conditions/symptoms listed in the Table.
EARLY DISCOVERY SAVES LIVES
Are we powerless to make any positive impact? Far from it, when we examine the survival rates related to earlier discovery of a premalignant lesion or early stage disease and the vigilant implementation of an opportunistic screening program. If the cancer is detected early, as a carcinoma in situ or stage one disease, the 5-year survival rate is between 75% and 90%, depending on the study.2,10 Late-stage diagnosis is occurring not because oral cancer is particularly difficult to discover but rather due to lack of public awareness, coupled with a lack of routine opportunistic screening by educated professionals. In stark contrast, the fight against cervical cancer has made tremendous inroads. The reduction in the incidence and mortality rate of cervical cancer is largely due to the advent of opportunistic screening methods and public awareness campaigns, resulting in early detection.
Why is this examination not performed more routinely? If it is performed, why is it not done in a comprehensive manner utilizing both visual and tactile skills? In a panel discussion, it was suggested that the lack of oral cancer screening awareness comes from the fact that our profession does not generally deal with diseases like cancer. Other reasons cited by dental professionals included: lack of time; lack of confidence in performance, documentation, referral, and management; absence of financial remuneration for time required to perform a thorough extra- and intraoral exams; the perception of oral cancer as being rare (3 times more prevalent than cervical cancer and causing twice as many deaths); and being uncomfortable with introducing the subject to patients.
Have we inadvertently become “oral mechanics” or “cosmetologists,” rather than positioning our profession as a gatekeeper of the entire oral cavity contributing strongly to overall wellness? There are demands of today’s dental patient to have an attractive smile. Fulfilling this type of request comes with a high level of clinical gratification. However, when it comes to routine preventive care, there is often diminished patient compliance. Performing an oral cancer screening is a strong reminder to our dental patients that we are concerned with their entire oral health and overall body wellness. Failure to do so may be a strong contribution to why we have experienced less than satisfactory adherence or compliance to routine dental care.
The author wishes to acknowledge Brian Hill, Founder of the Oral Cancer Foundation (oralcancerfoundation.org) for his insight and direction in development of this article.
- American Dental Association. Facts about oral cancer. ada.org/public/topics/cancer_oral.asp#facts. Accessed January 11, 2010.
- The Oral Cancer Foundation. Oral cancer facts. oralcancerfoundation.org/facts/index.htm. Accessed January 11, 2010.
- Shah JP, Singh B. Keynote comment: Why the lack of progress for oral cancer? Lancet Oncology. 2006;7:356-357.
- Petersen PE. Strengthening the prevention of oral cancer: the WHO perspective. Community Dent Oral Epidemiol. 2005;33:397-399.
- Silverman S, Eversole LR, EL Truelove. Oral premalignancies and squamous cell carcinoma. Essentials of Oral Medicine. Hamilton, Ontario, Canada: BC Decker; 2002:186-187.
- Ries LAG, Eisner MP, Kosary CL, et al, eds. SEER cancer statistics review, 1973-1998. Bethesda, Md: National Cancer Institute; 2001. seer.cancer.gov/csr/1973_1998/index.html. Accessed January 11, 2010.
- The Oral Cancer Foundation. The HPV connection. oralcancerfoundation.org/hpv/index.htm. Accessed January 11, 2010.
- Hammarstedt L, Lindquist D, Dahlstrand H, et al. Human papillomavirus as a risk factor for the increase in incidence of tonsillar cancer. Int J Cancer. 2006;119:2620-2623.
- Haddad RI. Human papillomavirus infection and oropharyngeal cancer. Medscape CME Course, 2007. cme.medscape.com/viewarticle/559789. Accessed January 11, 2010.
- MedlinePlus. Oral cancer. nlm.nih.gov/ medlineplus/ency/article/001035.htm. Accessed January 11, 2010.
Disclosure: Ms. Jones reports no conflicts of interest.
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