Oral cancer and its prevention
Oral cancer or mouth cancer occurs in any part of the mouth. Oral cavity (mouth) cancer can occur on the lips, gums, tongue, roof of the mouth (palate) floor of the mouth (beneath the tongue) and parts of the throat.
Oral cancers are quite common. They are the 11th most common cancer worldwide and the most common cancer that occurs in the head and neck region. In Nigeria, a minimum of 1100 people were diagnosed with oral cancer in 2012 and about 750 people with oral cancer died that year. This is a very conservative figure based on the lack of accurate data. They occur more in men than in women and although it can occur at any age, they are most common after the age of 40 years with a peak age of 60 years.
The survival of oral cancer is poor, and less than 50 per cent of patients are alive after five years but early detection increases the chances of survival to 80 per cent. The poor survival rate is due to late presentation of patients to the hospital. This late presentation is because patients do not pay attention to the early signs and symptoms of oral cancer. People with mouth cancer may present with sore in the mouth that will not heal, lump in the mouth, unusual bleeding, white patches or red patches on the gums, tongue or mouth, changes in speech or difficulty pronouncing words, loose teeth, difficulty/pain in chewing or swallowing, a mass or lump in the neck, chronic sore throat or hoarseness and pain in the mouth and/or ears. However, experiencing these symptoms does not necessarily mean one has cancer because these signs and symptoms could be due to other reasons. Only a qualified medical practitioner can make this diagnosis.
Oral cancer starts when changes occur in the DNA of normal cells lining the various parts of the mouth causing the cells to grow and multiply abnormally. These changes occur repeatedly and over time.
The use of tobacco in various forms is the major known risk factor of oral cancer. Tobacco can be in smoked or smokeless forms. Smoked forms of tobacco include cigarettes, shisha, cigars and cigarillos. Tobacco products contain chemicals like tar, which can irritate the lining of the mouth when they burn and cause changes in the DNA of cells lining the mouth leading to oral cancer. People who consume alcohol excessively are also at risk of oral cancer. In fact, 60 per cent of oral cancers are caused by a combination of cigarette smoking and alcohol consumption. \
Smokers are 15 times more likely to have oral cancer compared to non-smokers. Alcohol consumption with combustible tobacco use increases the risk of oral cancer even more. The use of shisha is becoming commoner in our society. Unfortunately, many of the shisha products sold in the country are from unregulated sources and they may contain elevated levels of cancer-causing agents. The habit of placing the burning end of the cigarette into the mouth adopted by some people has an even higher risk of causing cancer because of the heat applied directly to the tissues of the mouth.
Smokeless tobacco use in Nigeria is commoner among older people who use snuff. They might either apply it inside their cheeks or nose. These agents stay in contact with the gums and mucosa of the nose, irritate it and increase the risk of cancer development. Snus, a creamy snuff-like paste consisting of tobacco, clove oil, glycerin, spearmint, menthol, and camphor sold in a toothpaste tube popular in India and Sweden is marketed to younger people as a trendier/more fashionable product. Other agents that can cause mouth cancer include chewing Areca nut, betel nut, paan or gutka wrapped in tobacco leaves.
Human papilloma virus (HPV) infection is known to cause oral cancer and especially throat cancer. HPV is usually transmitted via oral sex, which is common among young people. Some chemicals or agents found in the workplace like in asbestos fibres, wood dust, dry-cleaning solvents or certain types of paint or industrial chemicals can increase the chance of having oral cancer.
Poor oral health and gum disease have been linked to cancers of the oral cavity; severe sun exposure may cause skin cancer on the lip. People with low immunity such as people living with AIDS and people who have received organ transplant have a higher risk of developing oral cancer. A diet low in fruits and vegetables and Vitamin A increases the risk of oral and or pharyngeal cancer. Having one or more of these risk factors does not mean you will develop head and neck cancer. You should talk to your dentist if you have any concerns. It is important to note that 25 – 40 per cent of people who develop oral cancer don’t smoke or have other known risk factors.
Individuals with oral cancer need not feel hopeless as there are treatments options available to treat oral cancers to enable them live well and long. Treatment includes surgery, radiotherapy and chemotherapy. Yearly newer drugs are being discovered that have improved the chances of long-term survival.
Is there any hope for the prevention of oral cancer? Certainly! Prevention begins with you avoiding the major causes of oral cancer. Stop smoking and reduce the consumption of all forms of alcoholic beverages. Going for a regular dental check-up, every six months ensures early detection of any abnormality in the mouth.
Also, as an individual, you can do a monthly self-check of your oral cavity. In front of a mirror and bright light, remove any dentures, with washed hands look and feel inside your lips and the front of your gums. Do not ignore any suspicious lump or change in colour in your mouth. Go for a check-up at the dentist. Visit your dentist every six months to have a professional check-up.
As a society, the government has taken some steps in the control of the sale and use of tobacco by placing a ban on the advertisement of tobacco products and implementing the labeling of cigarette packs with warning labels. However, the government still has a lot to do. For example, there is prohibition of sale or access to tobacco products to persons below 18 years of age among other laws in the National Tobacco act (NTC Act) but the enforcement of such laws is grossly lacking.
The excessive consumption of alcohol should be discouraged through media campaigns and regulated sales. Also, the use of industrial chemicals should be regulated and there must be enforcement of safety protocols for workers in industrial complexes.
Advocacy to raise awareness of these diseases and their risk factors in our society, particularly by health workers and non-governmental organisations is desirable. A more preventive approach should be adopted by both healthcare workers and society at large. For those that have already been exposed to the risk factors, smoking cessation programmes are to be initiated, and tobacco substitutes offered to willing patients. The Lagos University Teaching Hospital (LUTH) offers such preventive services to those who need to quit. Healthcare workers at all levels should be trained to recognise the early symptoms of oral cancer and promptly refer such patients appropriately for specialist care to the Cancer center at LUTH.
Drs. Effiom, Akinshipo and Aforka are of the Department of Oral Pathology, while Prof. Uti is of the Department of Preventive Dentistry, College of Medicine, University of Lagos.