Purpose of This PDQ Summary
Summary of Evidence
Significance
Evidence of Benefit
Get More Information From NCI
Changes To This Summary (04/03/2008)
Questions or Comments About This Summary
More Information

Purpose of This PDQ Summary

This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about oral cancer screening. This summary is reviewed regularly and updated as necessary by the PDQ Screening and Prevention Editorial Board ¹.

Information about the following is included in this summary:

• Oral cancer incidence and mortality statistics and information about oral cancer risk factors.
• Oral cancer screening modalities.

This summary is intended as a resource to inform clinicians and other health professionals about currently available oral cancer screening modalities. The PDQ Screening and Prevention Editorial Board uses a formal evidence ranking system ² in reporting the evidence of benefit and potential harms associated with each screening modality. It does not provide formal guidelines or recommendations for making health care decisions. Information in this summary should not be used as a basis for reimbursement determinations.

This summary is also available in a patient version ³, which is written in less technical language.

Summary of Evidence

Note: Separate PDQ summaries on Oral Cancer Prevention ⁴ and Lip and Oral Cavity Cancer Treatment ⁵ are also available.

There is inadequate evidence to establish that screening would result in a decrease in mortality from oral cancer.

Description of the Evidence

• Study Design: Evidence obtained from one randomized controlled trial.
• Internal Validity: Poor.
• Consistency: Not applicable.
• Magnitude of Effects on Health Outcomes: No evidence of benefit or harm.
• External Validity: Poor.

Significance

An estimated 35,310 new cases of oral cancer are expected to be diagnosed in the United States in 2008, and an estimated 7,590 people will die of the disease.[1] This form of cancer accounts for about 3% of cancers in men [1] and 2% of cancers in women.[2] Oral cancer occurs more frequently in blacks than in whites.[3]

More than 90% of oral cancers occur in patients older than 45 years. The incidence increases steadily until age 65 years, when the rate levels off. Over the last 22 years, there have been slight decreases in incidence and mortality rates. Reports have noted a substantial increase in the incidence of oral cancer (particularly of the tongue) among adults younger than 40 years in the United States between 1973 and 1997.[4]

The primary risk factors for oral cancer in American men and women are tobacco (including smokeless tobacco) and alcohol use. Infection with human papillomavirus 16 has been associated with an excess risk of developing squamous cell carcinoma of the oropharynx.[5]

No population-based screening programs for oral cancers have been implemented in developed countries, although "opportunistic screening" has been advocated.[6,7] There are different methods of screening for oral cancers. Oral cancer occurs in a region of the body that is generally accessible to physical examination by the patient, the dentist, and the physician, and visual examination is the most common method used to detect visible lesions. Other methods have been used to augment clinical detection of oral lesions and include toluidine blue, brush biopsy, and fluorescence staining.

Screening examination can be made more efficient by inspecting the high-risk sites where 90% of all oral squamous cell cancers arise: the floor of the mouth, the ventrolateral aspect of the tongue, and the soft palate complex.[8] An inspection of the oral cavity is often part of a physical examination in a dentist's or physician's office. It has been pointed out that high-risk individuals visit their medical doctors more frequently than they visit their dentists. Although physicians are more likely to provide risk-factor counseling (such as tobacco cessation), they are less likely than dentists to perform an oral cancer examination.[9] Overall, only a fraction (~20%) of Americans receive an oral cancer examination. Black patients, Hispanic patients, and those who have a lower level of education are less likely to have such an examination, perhaps because they lack access to medical care.[9] An oral examination often includes looking for leukoplakia and erythroplastic lesions, which can progress to cancer.[10] One recent study has shown that direct fluorescence visualization (using a simple hand-held device) could identify subclinical high-risk fields with cancerous or precancerous changes in the oral mucosa.[11] However, this finding has not yet been tested in a screening setting. Recent data suggest that molecular markers may be useful as markers of prognosis for these premalignant oral lesions.[12]

Although it is possible to detect and cure early-stage oral cancers, most oral cancers are moderately advanced (regional stage) at the time of diagnosis. Unfortunately, this pattern has not changed over time.

References

1. American Cancer Society.: Cancer Facts and Figures 2008. Atlanta, Ga: American Cancer Society, 2008. Also available online. ⁶ Last accessed October 1, 2008. 
   
   
2. American Cancer Society.: Cancer Facts and Figures 2004. Atlanta, Ga: American Cancer Society, 2004. Also available online. ⁷ Last accessed January 21, 2008. 
   
   
3. Ries LA, Kosary CL, Hankey BF, et al., eds.: SEER Cancer Statistics Review 1973-1995. Bethesda, Md: National Cancer Institute, 1998. 
   
   
4. Schantz SP, Yu GP: Head and neck cancer incidence trends in young Americans, 1973-1997, with a special analysis for tongue cancer. Arch Otolaryngol Head Neck Surg 128 (3): 268-74, 2002.  [PUBMED Abstract]
   
   
5. Mork J, Lie AK, Glattre E, et al.: Human papillomavirus infection as a risk factor for squamous-cell carcinoma of the head and neck. N Engl J Med 344 (15): 1125-31, 2001.  [PUBMED Abstract]
   
   
6. Opportunistic oral cancer screening: a management strategy for dental practice. BDA Occasional Paper 6: 1-36, 2000 Also available online. ⁸ Last accessed January 21, 2008. 
   
   
7. Update January 1992: the American Cancer Society guidelines for the cancer-related checkup. CA Cancer J Clin 42 (1): 44-5, 1992 Jan-Feb.  [PUBMED Abstract]
   
   
8. Mashberg A, Barsa P: Screening for oral and oropharyngeal squamous carcinomas. CA Cancer J Clin 34 (5): 262-8, 1984 Sep-Oct.  [PUBMED Abstract]
   
   
9. Kerr AR, Changrani JG, Gany FM, et al.: An academic dental center grapples with oral cancer disparities: current collaboration and future opportunities. J Dent Educ 68 (5): 531-41, 2004.  [PUBMED Abstract]
   
   
10. Chiodo GT, Eigner T, Rosenstein DI: Oral cancer detection. The importance of routine screening for prolongation of survival. Postgrad Med 80 (2): 231-6, 1986.  [PUBMED Abstract]
    
    
11. Poh CF, Zhang L, Anderson DW, et al.: Fluorescence visualization detection of field alterations in tumor margins of oral cancer patients. Clin Cancer Res 12 (22): 6716-22, 2006.  [PUBMED Abstract]
    
    
12. Poh CF, Zhang L, Lam WL, et al.: A high frequency of allelic loss in oral verrucous lesions may explain malignant risk. Lab Invest 81 (4): 629-34, 2001.  [PUBMED Abstract]
    
    

Evidence of Benefit

The routine examination of asymptomatic and symptomatic patients can lead to detection of earlier stage cancers and premalignant lesions. There is no definitive evidence, however, to show that this screening can reduce mortality.[1,2]

In Sri Lanka and India, three large studies of screening for oral cancer (involving more than 250,000 patients) have shown that it is possible for primary health care workers to detect premalignant lesions and early cancers in these populations at high risk due to habits of tobacco and betel nut chewing and reverse smoking (placing the lit end of the cigarette in the mouth).[3-5] The general results of these studies were as follows: (1) 12% to 26% of screened participants had oral lesions that did not require referral to a specialist; (2) 1.3% to 4.2% of screened patients had referable oral mucosal lesions, and of these, 45% to 80% were correctly referred; (3) the false-positive rate ranged from 9% to 29%; and (4) primary health care workers detected a total of 44 new oral cancers.

Compliance rates of these studies varied from 54% to 72%, and poor compliance following initial screening make feasibility of these types of studies uncertain. Health education programs only marginally increased compliance rates. Compliance problems of the Indian and Sri Lankan studies are likewise a possibility in the United States and other countries, which also have experienced suboptimal compliance among high-risk tobacco and alcohol users.[6] Contradictory oral cancer screening recommendations have been issued by the U.S. Preventive Health Services Task Force (against) and the American Dental Association (for).[1] Oral exfoliative cytology is the most extensively studied screening procedure of U.S. oral screening programs. Problems encountered with this screening method include a high proportion of false-negative examinations and poor voluntary participation by the highest-risk individuals (heavy tobacco and alcohol users). New screening techniques using brush biopsy have been developed. Despite limitations, these techniques have improved the sensitivity (92.3%) (95% CI, 74.9–99.9%) and specificity (94.3%) (95% CI, 86.0–98.4%) for detection of oral squamous cell carcinoma or dysplasia when tested on visually identified lesions.[7,8]

References

1. Screening for oral cancer. In: Fisher M, Eckhart C, eds.: Guide to Clinical Preventive Services: an Assessment of the Effectiveness of 169 Interventions. Report of the U.S. Preventive Services Task Force. Baltimore, Md: Williams & Wilkins, 1989, pp 91-94. 
   
   
2. Antunes JL, Biazevic MG, de Araujo ME, et al.: Trends and spatial distribution of oral cancer mortality in São Paulo, Brazil, 1980-1998. Oral Oncol 37 (4): 345-50, 2001.  [PUBMED Abstract]
   
   
3. Warnakulasuriya KA, Nanayakkara BG: Reproducibility of an oral cancer and precancer detection program using a primary health care model in Sri Lanka. Cancer Detect Prev 15 (5): 331-4, 1991.  [PUBMED Abstract]
   
   
4. Mehta FS, Gupta PC, Bhonsle RB, et al.: Detection of oral cancer using basic health workers in an area of high oral cancer incidence in India. Cancer Detect Prev 9 (3-4): 219-25, 1986.  [PUBMED Abstract]
   
   
5. Warnakulasuriya KA, Ekanayake AN, Sivayoham S, et al.: Utilization of primary health care workers for early detection of oral cancer and precancer cases in Sri Lanka. Bull World Health Organ 62 (2): 243-50, 1984.  [PUBMED Abstract]
   
   
6. Prout MN, Sidari JN, Witzburg RA, et al.: Head and neck cancer screening among 4611 tobacco users older than forty years. Otolaryngol Head Neck Surg 116 (2): 201-8, 1997.  [PUBMED Abstract]
   
   
7. Sciubba JJ: Improving detection of precancerous and cancerous oral lesions. Computer-assisted analysis of the oral brush biopsy. U.S. Collaborative OralCDx Study Group. J Am Dent Assoc 130 (10): 1445-57, 1999.  [PUBMED Abstract]
   
   
8. Scheifele C, Schmidt-Westhausen AM, Dietrich T, et al.: The sensitivity and specificity of the OralCDx technique: evaluation of 103 cases. Oral Oncol 40 (8): 824-8, 2004.  [PUBMED Abstract]
   
   

Get More Information From NCI

Call 1-800-4-CANCER

For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 9:00 a.m. to 4:30 p.m. Deaf and hard-of-hearing callers with TTY equipment may call 1-800-332-8615. The call is free and a trained Cancer Information Specialist is available to answer your questions.

Chat online

The NCI's LiveHelp® ⁹ online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 9:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.

Write to us

For more information from the NCI, please write to this address:

NCI Public Inquiries Office

Suite 3036A

6116 Executive Boulevard, MSC8322

Bethesda, MD 20892-8322

Search the NCI Web site

The NCI Web site ¹⁰ provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use our “Best Bets” search box in the upper right hand corner of each Web page. The results that are most closely related to your search term will be listed as Best Bets at the top of the list of search results.

There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.

Find Publications

The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator ¹¹. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237), TTY at 1-800-332-8615.

Changes To This Summary (04/03/2008)

The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.

Significance ¹²

Updated incidence and mortality estimates ¹³ for 2008 (cited American Cancer Society as reference 1).

Questions or Comments About This Summary

If you have questions or comments about this summary, please send them to Cancer.gov through the Web site’s Contact Form ¹⁴. We can respond only to email messages written in English.

More Information

About PDQ

• PDQ® - NCI's Comprehensive Cancer Database ¹⁵.

  Full description of the NCI PDQ database.

Additional PDQ Summaries

• PDQ® Cancer Information Summaries: Adult Treatment ¹⁶

  Treatment options for adult cancers.

• PDQ® Cancer Information Summaries: Pediatric Treatment ¹⁷

  Treatment options for childhood cancers.

• PDQ® Cancer Information Summaries: Supportive and Palliative Care ¹⁸

  Side effects of cancer treatment, management of cancer-related complications and pain, and psychosocial concerns.

• PDQ® Cancer Information Summaries: Screening/Detection (Testing for Cancer) ¹⁹

  Tests or procedures that detect specific types of cancer.

• PDQ® Cancer Information Summaries: Prevention ²⁰

  Risk factors and methods to increase chances of preventing specific types of cancer.

• PDQ® Cancer Information Summaries: Genetics ²¹

  Genetics of specific cancers and inherited cancer syndromes, and ethical, legal, and social concerns.

• PDQ® Cancer Information Summaries: Complementary and Alternative Medicine ²²

  Information about complementary and alternative forms of treatment for patients with cancer.

Important:

This information is intended mainly for use by doctors and other health care professionals. If you have questions about this topic, you can ask your doctor, or call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).