There’s More to Oral Cancer Risks Than Alcohol and Tobacco

April is Oral Cancer Awareness Month, and dentistrytoday.com will be celebrating the event with blogs, news stories, and other features all spotlighting the disease. #OralCancerAwareness 

Think back to the “dark days” of dental school. Somewhere buried in the curriculum of prosthodontics, restorative, orthodontics, and periodontics, there was some mention of oral pathology. Apparently, since you would be spending your career looking into the mouths of your patients, you needed some instruction on the inspection and diagnosis of a variety of lesions of the oral cavity.

During your coursework you undoubtedly learned about leukoplakia and erythroplakia, as well as the possibility that some of these lesions might progress to oral cavity squamous cell carcinoma (OCSCC). You were taught that any ulcer that did not heal, erythroplakia, or suspicious appearing leukoplakia warranted a biopsy to rule out an early cancer.

You were also taught that most of these high-risk lesions would occur on the lateral surface of the tongue, floor of the mouth, or buccal mucosa and that heavy smokers and drinkers were especially at risk for SCC. 

Fortunately, your education was excellent and these tenets hold true even today. Tobacco abuse is the single highest risk factor in the development of OCSCC. Heavy alcohol consumption still comes in at a close second place. 

The Risk Factors 

Certainly, smoking rates in the United States are decreasing, and you are seeing fewer of these types of patients, depending on where you practice. When patients ask you about their risk for oral cancer, perhaps you examine their oral cavity carefully, counsel them to avoid tobacco and alcohol, and send them on their way. But there is much more to the story of OCSCC than tobacco and alcohol, and your patients deserve more information about the prevention of this life-threatening disease.

The development of these lesions is a complex interplay between environmental risk factors such as tobacco or alcohol, genetic predisposition, immune system function, diet, inflammatory or autoimmune processes, and a variety of other factors that may lead to the development of SCC.

It is also true that SCC continues to be a life-threatening disease, unless it is recognized at an early stage. The National Institute of Dental and Craniofaxial Research reports that the overall 5-year survival rate of oral cancer is approximately 60%. But if caught early, usually by the general dentist or primary care physician, the survival rates are closer to 80%, the American Cancer Society states.  

Even if your patients frequently report that they do not smoke and do not consume large quantities of alcohol, you still need to be aware of the wide variety of information that is known related to the risk of oral cavity cancer (and cancer in general) and the strategies to help your patients avoid head and neck cancer.

Advice for Prevention 

In 2007, the World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) released personal recommendations for the prevention of cancer. Recent data indicate that individuals with a lifestyle adherent to the WCRF/AICR recommendations had an almost 70% reduced risk of head and neck cancers.¹ It is important to be aware of the following guidelines and to inform your patients interested in cancer prevention about them.

• Body fatness: Patients should maintain a body weight that’s within the normal range from the age of 21 years (body mass index of 21 to 23), avoiding weight gain and increases in weight circumference throughout adulthood. 

• Physical activity: Patients should be moderately physically active, equivalent to walking briskly, for at least 30 minutes every day. As fitness improves, patients should aim for 60 minutes or more of moderate or 30 minutes or more of vigorous physical activity every day.

• Food and drinks that promote weight gain: Patients should consume energy-dense foods sparingly, avoid sugary drinks, and consume fast food sparingly, if at all. 

• Plant foods: Patients should eat at least 5 portions or servings (at least 400 g or 14 oz) of a variety of nonstarchy vegetables and fruits every day. They also should eat relatively unprocessed cereals (grains) and/or pulses (legumes) with every meal. And, they should limit refined, starchy foods.

• Animal foods: People should consume less than 500 g (18 oz) or red meat a week, and very little, if any, should be processed meat.

• Alcoholic beverages: Patients should limit alcohol consumption to no more than 2 drinks a day for men and one drink a day for women. 

• Preservation, processing, and preparation: Patients should avoid salt-preserved, salted, or salty foods. They also should preserve foods without using salt and limit consumption of processed foods with added salt to ensure an intake of less than 6 g (2.4 g sodium) a day. And, they shouldn’t eat moldy cereals (grains) or pulses (legumes).

• Dietary supplements: Dietary supplements are not recommended for cancer prevention. 

There is a known association between obesity and cancer. Many patients might be surprised to know that following these guidelines not only is a way to live a healthier lifestyle, but also an excellent way to reduce their risk of head and neck cancer.

What About Oral Hygiene?

Did you know that periodontal disease is associated with oral cancer, even when you control for tobacco and alcohol consumption? Keep in mind that regular visits to the dentist and good oral hygiene all have been associated with reduced rates of oral cavity cancer and early diagnosis.^2-4

Informing your patients of this fact not only will improve their oral health, but it also is an excellent way to motivate them to improve their oral hygiene and reduce their risk of cancer. Additionally, remember to check with them regarding how frequently they use mouth rinses that include alcohol and recommend alcohol-free rinses instead to further reduce risk.⁵

What About HPV?

Recently, the media’s coverage of the human papillomavirus (HPV) “epidemic” has our patients’ attention and has raised both awareness and concern. HPV is the same virus that causes cervical cancer, and oral sex is the primary transmission modality.⁶

Genital HPV is the most common sexually transmitted infection in the United States, with an estimated 6.2 million people becoming newly infected every year.⁷ The prevalence of active HPV infection in the population is approximately 7% in the United States.⁸

This disease frequently affects a younger, nonsmoking population. Undoubtedly, this has prompted the realization that anyone with a tonsil mass, base of tongue mass, or new neck mass or swollen lymph node (the most common presentation) should be evaluated for this disease. Patients also should talk to their primary care physician about vaccinating their children to prevent this disease in future generations.

High-risk HPV, which includes the HPV16 and HPV18 strains, has resulted in a dramatic risk in the incidence of oropharyngeal (tongue base and tonsil) squamous cell carcinoma. While many people are exposed to HPV at some point in their lifetime, it appears that in contrast to the oropharynx, HPV does not appear to play as important of a role in cancers of the oral cavity.^9,10

There are varied reasons for this phenomenon that center around the tendency of the virus to preferentially penetrate the lymphoid mucosa of the oropharynx. Therefore, your patients do not need to be overly concerned about oral HPV infection for lesions of the oral cavity. 

Other Groups at Higher Risk

While we tend to focus on smokers as the high-risk group in our practices, it turns out that there is a variety of other conditions that predispose patients to the development of oral cancer. These patients should be carefully examined and counseled about their risk of cancer to facilitate early recognition and treatment. The following groups of patients are at increased risk of oral cavity cancer and deserve special consideration in your practice:

• Transplant patients¹¹
• Other immune-suppressed populations (HIV, hepatitis C)¹²
• Inflammatory bowel disease (Chron’s, ulerative colitis)¹³
• Chronic candidiasis infection¹⁴
• Lichen planus (relatively low transformation rate of approximately 1% to 3%)¹⁵
• Diabetes (Type II)¹⁶
• Fanconi anemia¹⁷
• Autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis), which may be associated with the diseases or treatment of the disease

Conclusion

An increased understanding of the risk factors for oral cavity cancer beyond the traditional tobacco and alcohol can save lives. Remember that as a practicing dentist, you are in the position to educate patients about their risks, provide strategies for prevention, and ultimately diagnose oral cancer at an early stage when a cure is possible. Education, prevention, and early diagnosis and management are the most important factors in improving the chances for survival.

References

1. Bravi F, Polesel J, Garavello W, et al. Adherence to the World Cancer Research Fund/American Institute for Cancer Research recommendations and head and neck cancers risk. Oral Oncol. 2017;64:59-64. 

2. Chen F, He BC, Yan LJ, et al. Influence of oral hygiene and its interaction with standard of education on the risk of oral cancer in women who neither smoked nor drank alcohol: a hospital-based, case-control study. Br J Oral Maxillofac Surg. 2017;55:260-265.

3. Javed F, Warnakulasuriya S. Is there a relationship between periodontal disease and oral cancer? A systematic review of currently available evidence. Crit Rev Oncol Hematol. 2016;97:197-205. 

4. Yeung CA. Referrals to dentists by GPs could delay diagnosis of oral cancer. BMJ. 2017;356:i6784.

5. Wilson G, Conway DI. Mouthwash use and associated head and neck cancer risk. Evid Based Dent. 2016;17:8-9.

6. Berman TA, Schiller JT. Human papillomavirus in cervical cancer and oropharyngeal cancer: one cause, two diseases. Cancer. 2017 Mar 27. [Epub ahead of print] 

7. Weinstock H, Berman S, Cates W Jr. Sexually transmitted diseases among American youth: incidence and prevalence estimates, 2000. Perspect Sex Reprod Health. 2004;36:6-10. 

8. Gillison ML, Broutian T, Pickard RK, et al. Prevalence of oral HPV infection in the United States, 2009-2010. JAMA. 2012;307:693-703.

9. Zafereo ME, Xu L, Dahlstrom KR, et al. Squamous cell carcinoma of the oral cavity often overexpresses p16 but is rarely driven by human papillomavirus. Oral Oncol. 2016;56:47-53.

10. Mirghani H, Amen F, Moreau F, et al. Do high-risk human papillomaviruses cause oral cavity squamous cell carcinoma? Oral Oncol. 2015;51:229-236.

11. Liu Q, Yan L, Xu C, et al. Increased incidence of head and neck cancer in liver transplant recipients: a meta-analysis. BMC Cancer. 2014;14:776.

12. Mahale P, Sturgis EM, Tweardy DJ, et al. Association between hepatitis C virus and head and neck cancers. J Natl Cancer Inst. 2016;108(8).

13. Katsanos KH, Roda G, McBride RB, et al. Increased risk of oral cancer in patients with inflammatory bowel diseases. Clin Gastroenterol Hepatol. 2016;14:413-420.

14. Hettmann A, Demcsák A, Decsi G, et al. Infectious agents associated with head and neck carcinomas. Adv Exp Med Biol. 2016;897:63-80.

15. Gonzalez-Moles MA, Gil-Montoya JA, Ruiz-Avila I, et al. Is oral cancer incidence among patients with oral lichen planus/oral lichenoid lesions underestimated? J Oral Pathol Med. 2017;46:148-153. 

16. Gong Y, Wei B, Yu L, et al. Type 2 diabetes mellitus and risk of oral cancer and precancerous lesions: a meta-analysis of observational studies. Oral Oncol. 2015;51:332-340.

17. Bhanu Prasad V, Mallick S, Upadhyay AD, et al. Systematic review and individual patient data analysis of pediatric head and neck squamous cell carcinoma: an analysis of 217 cases. Int J Pediatr Otorhinolaryngol. 2017;92:75-81. 

Dr. Miles is co-chief of the Division of Head and Neck Cancer Surgery, Mount Sinai Health System, and associate professor of otolaryngology at the Icahn School of Medicine at Mount Sinai. He also is a Fellow of the American College of Surgeons and a Diplomate of the American Board of Otolaryngology and the American Board of Oral and Maxillofacial Surgery. He can be reached at brett.miles@mountsinai.org.

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