Oral Cancer And Tobacco Use

Overview

Cancer is a condition that causes the cells of the affected area to grow and multiply uncontrollably. The cancer cells can invade and destroy the surrounding healthy tissue and organs.

Oral cancer is also known as mouth cancer. It can affect any part of the mouth, including the tongue, inside the cheeks, gums, and lips. Cancer cells contain instructions for multiplying and mutating abnormal or damaged cells. Oral cancer can be caused by using tobacco, drinking alcohol, or due to human papillomavirus (HPV).^1,2,5

Tobacco contains substances like nicotine, carbon monoxide, tar, and toxic chemicals such as benzene, arsenic, and formaldehyde. Nicotine is an addictive substance, that causes serious damage to the body. Tobacco use is the main risk factor for oral cancer. All types of tobacco products including cigarettes, cigars, pipe tobacco, chewing tobacco and snuff are harmful.^4,5

Understanding oral cancer

Oral cancer is the most common form of cancer seen in the head and neck area. Cancer occurs due to a change in the DNA cells, commonly seen in thin cells called squamous cells, which line the lips and inside of the mouth.³ The mutated DNA cells grow and multiply and start to spread to other areas of the mouth, head, neck and other parts of the body.¹ 

Areas of the oral cavity where cancer can occur are : 

• Lips
• Gums (gingiva)
• The inside lining of the cheek
• Tongue
• The floor and roof of the mouth

Oral cancer is explained by the TNM staging system:⁵

• T indicates the size and location of the tumour 
• N indicates whether the tumour is spread to lymph nodes  
• M indicates tumour is metastasis and spread to other areas of the body

Symptoms

Several signs and symptoms can indicate a precancerous condition.⁵ 

Some of the symptoms are : 

• Leukoplakia: A condition where white or grey patches develop in the mouth. These patches cannot be removed by rubbing. It is an increased risk for oral cancer.
• Erythroplakia: This affects the mucous membrane of the mouth. Red lesions appear along with the white patches. Erythroplakia patches can be cancerous and non-cancerous.
• Ulcerative lesions: Sores on the lip and inside of the mouth that can bleed easily and do not heal within two weeks
• Bleeding in the mouth without any reason
• Numbness, pain or tenderness on the face, neck or in the mouth
• Difficulty in chewing, swallowing, voice changes
• Restricted tongue or jaw movements
• Unexplained weight loss
• Earache
• Bad breath
• Loose teeth

Tobacco use

• Tobacco is considered a major risk factor for head and neck cancer, and mainly oral cancer.⁴
• Cigarettes, electronic cigarettes, and smokeless tobacco cause gum disease, oral cancer and other health problems.
• Smoking also affects the non-smokers who live with them, they are also inhaling the smoke and can have health issues.⁶
• The risk of getting cancer is higher in smokers than in non-smokers, alcohol use further increases the risk of cancer.

Oral presentations of tobacco use

• Smoker’s melanosis: It is a condition where an increased tissue pigmentation or darkening is seen in the upper and lower front teeth due to irritation from tobacco smoke.
• Periodontal disease: It is the condition where there is a loss of bone structure that supports the teeth. Smokers are at risk of developing periodontal disease which can lead to mobile teeth. The positive results of the periodontal treatment are reduced in chronic smokers.⁷
• Nicotinic stomatitis: It is the condition where the hard palate (roof of the mouth) appears white instead of pink. This is due to tiny salivary glands which are affected by the smoke and heat caused by tobacco products. Individuals who develop this condition are more likely to develop cancer of the tonsillar area and lungs.
• Betel Nut: Smokeless tobacco use can affect the oral tissue and the teeth if the substance is held in the mouth.

Diagnosis

A dentist will most likely identify the signs of oral cancer during regular checkups. Patients will be referred to a specialist for a biopsy of a suspicious lesion to confirm a cancer diagnosis. During the examination, the health care provider may ask about habits, history of any disease and family history of cancer.

1. Physical examination: Healthcare providers will examine the mouth, head and neck. They will look for any abnormalities, sores, white patches or swollen lymph nodes.
2. Biopsy: It is a small procedure where a small piece of tissue is taken from the area affected and sent to a laboratory for testing by a pathologist. A pathologist with provide a formal histology report which will confirm the presence of cancer.
3. Endoscopy: In this procedure, a flexible tube with a camera attached to the end is passed through the mouth into the throat. The camera provides images of the structures and abnormal tissue areas.
4. Imaging tests: Various imaging tests are used to determine the extent of the condition. According to the symptoms, the doctor may recommend the test that should be taken. CT (computed tomography), x-ray, MRI (magnetic resonance imaging) and positron emission tomography (PET) will determine the stages of the disease and the area affected.

Treatment

Cancer treatment depends upon the location and stage of the cancer and also considers the overall health of the affected individual. Treatment options are: 

1. Surgery: Surgeons may resect the tumour plus a small border of healthy cells to ensure that all cancer cells. Surrounding lymph nodes may be tested intra-operatively or removed intra-operatively as a precaution to avoid the spread. This is done under general anaesthesia.
2. Radiation therapy: Radiation therapy is used alone in the early stages of mouth cancer, but in advanced stages, it is done after surgery. Radiation therapy uses high-powered X-ray beams to kill cancer cells.⁸
3. Chemotherapy: It is a treatment using drugs that can kill cancer cells, it increases the effectiveness of radiation therapy. Some of the side effects are nausea, vomiting and hair loss.⁹
4. Targeted drug therapy: This cancer treatment is done using certain drugs which identify and attack cancer cells without harming the healthy cells. This treatment is used alone or in combination with chemotherapy or radiation therapy.¹⁰
5. Immunotherapy: Immunotherapy helps the individual's immune system to attack the cancer cells. The immune system identifies and destroys the cancerous cells, it is very effective and helps people with cancer to live longer. 

Risk factors

Factors that increase the chance of getting cancer are:¹¹ 

• Usage of tobacco of any kind (e.g.which cigarettes, cigars, pipe, chewing tobacco, snuff)
• Drinking alcohol
• Chewing tobacco or betel quid
• Having a family history of cancer
• Unhealthy diet, where there is a lack of fruits and vegetables
• Weak immune system
• Excessive exposure to sunlight (UV rays) 
• Sexually transmitted virus - human papillomavirus²

Prevention

• Stop using tobacco in any form or if using already then reduce the usage
• Reduce the intake of alcohol if there is a drinking habit
• Get vaccinated for human papillomavirus
• Have regular health checkups including dental checkups
• Enjoy a well-balanced diet
• Engage in regular exercise
• Use a sunscreen or a hat to protect from excessive exposure to sunlight

Summary

Oral cancer is the most common form of cancer seen in the head and neck area. Cancer occurs due to the change in the DNA of cells and is commonly seen in thin cells called squamous cells The cells line the lips and inside of the mouth. The mutated DNA cells grow and multiply and start to spread to areas of the mouth, head, neck and other parts of the body. Tobacco contains cancer-causing substances like nicotine, carbon monoxide, tar, and toxic chemicals such as benzene, arsenic and formaldehyde. Tobacco use is the main risk factor for oral cancer. All types of tobacco products including cigarettes, cigars, pipe tobacco, chewing tobacco and snuff are harmful to health. Treatment of oral cancer depends upon the site and the stage of the cancer.

FAQs

What is the most common cause of oral cancer?

Oral cancer most commonly occurs due to the use of tobacco products, and alcohol and due to the human papillomavirus (HPV).

How does tobacco use cause oral cancer?

Tobacco contains chemicals (toxins), carbon monoxide, and other cancer-causing agents. 

What are the symptoms of oral cancer?

Symptoms of oral cancer depend on the area where it is affected. The most common symptoms are ulcerative sores on the lips and in the mouth that do not heal.

Can oral cancer be caused by smokeless tobacco?

Oral cancer can be caused by smokeless tobacco products. The cancer can affect the mouth, tongue, cheek and gum.