What is Oral Cancer?
Cancer occurring in the tissues of oral cavity (begins at the lips and extends backwards to the front part of the tonsils) or oropharynx (part of the throat) is termed as oral cancer.
Oral Cavity [1]
Different parts in your oral cavity
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Epidemiology
India has one third of oral cancer cases in the world [2].
Oral cancer accounts for around 30% of all cancers in India [3].
Oral cancers in India (Globocan, 2012) [4]:
New cases: 77,003
Deaths: 52,067
In general, more men suffer and die from oral cancer than women [5].
Risk Factors
- Tobacco consumption
- All forms of tobacco, including cigarettes, beedi, pipes, cigars, and chewing (smokeless) tobacco, can cause oral cancer [6,7].
- Keeping tobacco quid inside mouth may lead to cancer of cheek, gums and inner cavity of mouth
- Paan and betel nut are also causal agents [8].
- Alcohol consumption: Alcohol increases the risk of oral cancer [9]. The risk is about twice as high in people who have 3 to 4 alcoholic drinks per day compared to those who don’t drink alcohol [10,11].
The risk of oral cancer is even higher in people who use both alcohol and tobacco [12].
- Sharp teeth or ill fitting dentures: Chronic irritation of gums and cheek by ill fitting dentures or sharp teeth is a risk factor [13].
- Diet : Lack of proper nutrition and diet low in fruits and vegetables: linked with an increased risk of cancers of the oral cavity and oropharynx [14].
- Human Papillomavirus (HPV): Infection with certain high risk HPV types increases the risk of oral cancer, especially in younger people [15,16].
- Weak immune system: people with weakened immunity are more prone to suffer from oral cancers. Certain immune deficiency diseases at birth, radiotherapy and chemotherapy, medicines given to organ transplant recipients and the Acquired immunodeficiency syndrome (AIDS) may be responsible for weakened immune system [17,18].
- Exposure to sun’s ultra violet rays: may cause lip cancer [17].
Signs and Symptoms [19]
- A persistent sore in the mouth, face or neck which does not heal
- Difficulty in opening the mouth
- Development of white, red or mixed patches on tongue, gums or inner linings of mouth
- A lump or hard mass in the neck
- Chronic pain in mouth, tongue/jaw pain
- Difficulty in chewing or swallowing
- Swelling, thickening, lumps or bumps on lips, gums or inner cavity of mouth
- Unexplained bleeding in mouth
- Hoarseness or change in voice
- Loose teeth and ill-fitting dentures
- Unexplained weight loss
Some of the above signs and symptoms may also be present in benign tumors of oral cavity as well as in other diseases or cancers. However, if they persist for more than 2 weeks, one should consult a doctor for further evaluation.
Diagnosis and Tests [20]
a. Medical history, General physical examination and Oral examination
A thorough history is taken before the examination regarding duration and frequency of tobacco use in any form like cigarette, beedi, chewing pan, gutka, khaini etc and of alcohol consumption.
Oral examination: A careful examination of entire inner cavity of the mouth which includes the roof of mouth, back of the throat, and inside of cheeks and lips is then carried out. The doctor looks for red or white patches or any other abnormal areas over head, neck or face. He/she also examines for any lumps, swelling or any other problem with the nerves of mouth or face. If any abnormal area is found during examination, it is confirmed by further tests which are detailed below.
b. Invasive tests:
- Brush cytology: In this test, the suspected area/lesion is brushed and the cells are looked at under microscope for abnormal cells by a pathologist.
- Fine Needle Aspiration Cytology (FNAC): In this test, a thin needle which is attached to a syringe is used to draw few cells from the suspected lump or swelling. These cells are smeared onto a glass slide, then stained and examined under microscope by a pathologist to examine for abnormal cells. FNAC is generally used to diagnose metastatic carcinoma of head and neck, in the cervical region. It is hardly ever utilized as a first line diagnostic modality.
- Biopsy: A small piece of tissue is taken from suspicious area using a punch biopsy instrument. Sometimes it may be done under the guidance of endoscopy, if the lesion is not easily accessible. This tissue is processed in the laboratory and examined for presence or absence of cancer.
c. Imaging tests: Imaging tests are done to confirm the diagnosis, document the extent of spread of disease, staging etc. The most common diagnostic imaging tests are X-rays, CT scan, MRI and PET scan.
d. Other tests:
Human Papillomavirus (HPV) Testing: Oral cancers with HPV infection are on the rise. Doctors may test the biopsy sample for the presence of HPV infection as the possible cause.
Early detection of oral and oropharyngeal cancers [20]
Many cancers of the oral cavity have a long early pre-cancer period which provide an opportunity to seek medical help through symptoms. Early detection of these cancers is possible during routine general health check-ups/screening by doctors/dentists/health workers or by self-examination.
Physical Examination of Oral Cavity
If symptoms persist for more than two weeks or if you detect any abnormal area on self examination, you should consult your doctor. He or she would take your medical history and exposure to risk factors. Then the doctor will examine your mouth carefully for any abnormal area and feel for any lump or for any other lesion with a gloved finger.
Oral Self Examination
You can examine your mouth yourself by looking at your mouth with the help of mirror in bright light, for early detection of oral cancers.
Procedure for oral self- examination [19]
- Wash your hands thoroughly
- Explore your mouth with your finger
- Tilt your head back; examine the roof of your mouth for any abnormal thickening.
- Pull the cheeks on one side at a time, inspect the inner surface and back of the gums.
- Pull out your tongue and hold it with finger upwards, inspect and feel the floor of the mouth and look carefully at the tongue.
- Feel on both sides of the neck for any lump or enlarged lymph nodes.
- If you detect any abnormality, bring it to the notice of your doctor for further evaluation.
Other tests: In addition to this clinical examination, a few other simple tests may be performed. The doctor may use simple dyes like toluidine blue with or without a focus light to look for abnormal areas, especially if you have a history of risk factors exposure.
If any abnormal areas are detected, the doctor may perform cytology or biopsy to rule out a cancerous lesion.
If the pathologist confirms that you have cancer, then your doctor will refer you to a specialist for further management.
References
[1] Oral anatomy. http://screening.iarc.fr/atlasoral_list.php?cat=H4&lang=1. Accessed on 3rd September, 2014
[2] Coelho KR. Challenges of the Oral Cancer Burden in India. J Cancer Epidemiol. 2012; Volume 2012, Article ID 701932. doi:10.1155/2012/701932
[3] Sankaranarayanan R, Ramadas K, Thomas G et al. Effect of screening on oral cancer mortality in Kerala, India: a cluster-randomised controlled trial. Lancet 2005;365:1927–33
[4] Ferlay J, Soerjomataram I, Ervik M, et al. GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC Cancer Base No. 11[Internet]Lyon, France: International Agency for Research on Cancer; 2013. Available from: http://globocan.iarc.fr, accessed on 6th August 2014
[5] Global oral cancer fact sheets. http://www.who.int/oral_health/publications/fact_sheet_tobacco/en/index1.html. Accessed on 10th September 2014
[6] Global Tobacco Adults Survey. Available at www.mohfw.nic.in/WriteReadData/l892s/1455618937GATS%20India.pdf;2009
[7] Pednekar MS, Gupta PC, Yeole BB, et al. Association of tobacco habits, including bidi smoking, with overall and site-specific cancer incidence: results from the Mumbai cohort study. Cancer Causes Control. 2011; 22(6): 859-68
[8] Lin WJ, Jiang RS, Wu SH, et al. Smoking, Alcohol, and Betel Quid and Oral Cancer: A prospective Cohort Study. J Oncol 2011;2011:525976
[9] IARC Monographs on the Evaluation of Carcinogenic Risks to Humans VOLUME 96 Alcohol Consumption and Ethyl Carbamate IARC 2010. Lyon, France. http://monographs.iarc.fr/ENG/Monographs/vol96/mono96.pdf. Accessed on 5th September 2014
[10] Turati F, Garavello W, Tramacere I, et al. A meta-analysis of alcohol drinking and oral and pharyngeal cancers: results from subgroup analyses. Alcohol Alcohol 2013;48:107-18
[11] Hashibe M, Brennan P, Benhamou S, et al. Alcohol drinking in never users of tobacco, cigarette smoking in never drinkers, and the risk of head and neck cancer: pooled analysis in the International Head and Neck Cancer Epidemiology Consortium. J Natl Cancer Inst 2007;99:777-89
[12] Znaor A, Brennan P, Gajalakshmi V, et al. Independent and combined effects of tobacco smoking, chewing and alcohol drinking on the risk of oral, pharyngeal and esophageal cancers in Indian men. Int J Cancer 2003;105:681-6
[13] Oral cavity and oropharyngeal cancer. http://www.cancer.org/acs/groups/cid/documents/webcontent/003128-pdf. Accessed on 7th September 2014
[14] World Cancer Research Fund/American Institute for Cancer Research. Food, Nutrition, Physical Activity, and the Prevention of Cancer-a Global Perspective. Washington DC:AICR;2007
[15] International Agency for Research on Cancer. List of Classifications by cancer sites with sufficient or limited evidence in humans, Volumes 1 to 105*. Available from http://monographs.iarc.fr/ENG/Classification/index.php. Accessed on 6th August 2014.
[16] Chocolatewala NM and Chaturvedi PJ. Role of human papilloma virus in the oral carcinogenesis: an Indian perspective. Cancer Res Ther. 2009; 5(2):71-7. HPV Infection in Young Australians. PLOS One 2014;6:1691-704.
[17] International Agency for Research on Cancer. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Volume 100D (2012). A Review of Human Carcinogens: Radiation. Geneva:WHO;2012
[18] Grulich AE, van Leeuwen MT, Falster MO, et al. Incidence of cancers in people with HIV/AIDS compared with immunosuppressed transplant recipients: a meta-analysis. Lancet 2007; 370:59-67.
[19] American Association of Oral and Maxillofacial Surgeons. https://www.aaoms.org/docs/media/oralcancerselfexam.pdf. Accessed on 22nd January 2015
[20] Early Detection, Diagnosis, and Staging. http://www.cancer.org/cancer/oralcavityandoropharyngealcancer/detailedguide/oral-cavity-and-oropharyngeal-cancer-diagnosis