What Is Oral Cancer

Have you noticed a lump on your lip that will not go away? Or maybe you’ve noticed red and white patches in your mouth that you can’t explain? These are symptoms that could indicate oral cancer. Oral Cancer is a type of cancer that comes under the umbrella of head and neck cancers. These include cancers that develop on your lip, tongue, cheeks, salivary glands, skull and throat. To find out more about Oral Cancer read below.

Overview

So what exactly is oral cancer? Using a strict definition oral cancer can refer to cancers that develop within tissues of the oral cavity. Your oral cavity is made up of:¹

• Your lips
• Cheeks
• First two-thirds of your tongue   
• The roof and floor of your mouth 
• Salivary Glands 

Oropharyngeal cancers are a prevalent subtype of Oral Cancer, which also includes tumours that occur within the oropharynx. The oropharynx is located directly behind your oral cavity and consists of the following: 

• The posterior third of your tongue
• Tonsils 
• Soft Palate, the sides and backs of your neck

Oral cavity cancer and oropharyngeal cancer are a type of cancer called squamous cell carcinoma. Which means they develop from a specific type of cell called squamous epithelial cells. 

Causes of oral cancer

Oral cavity and oropharyngeal cancers are head and neck cancers. The causes of head and neck cancers can be split into two categories: 

• HPV Negative 
• HPV-positive.

HPV-negative head and neck cancers describe the type of cancer that arises from long-term  exposure to cancer-causing chemicals known as carcinogens.² These carcinogens cause damage to the DNA of the cells and  they are exposed to causing mutations in genes that produce proteins that are supposed to prevent cancers known as tumour suppressors. As these normal cells lose the function of tumour suppressor genes, they become cancer cells as they develop more and more mutations that begin to multiply out of control, and  leading to cancer. 

The most common causes and sources  of carcinogens causing oral cavity and oropharyngeal cancer are tobacco smoking and alcohol use.^{2, 3} Smoking gives a higher risk than alcohol use, but together increases the risk drastically and in recent years the number of cases of HPV-negative head and neck cancers has fallen due to the decrease in smoking.² Chewing of the betel quid nut while uncommon in the UK is a significant  risk factor for mouth cancer.² The most common of this cancer is tongue cancer. 

HPV-positive head and neck cancer is caused by chronic infection with Human papillomavirus (HPV). HPV is a group of viruses of which there are over 100 however certain strains of HPV can cause cancers such as cervical cancer as well as head and neck cancers.⁴ HPV inactivates the tumour suppressors in the cells it infects causing them to become cancer cells. The number of people with HPV-positive head and neck cancer has been increasing in recent years and typically patients are younger than those in the HPV-negative cohort. While it is still uncertain, it is thought the risk of contracting HPV-positive cancer is a higher number of sexual partners. Oropharyngeal cancers are more likely to be HPV-positive cancers.⁴

Signs and symptoms of oral cancer

Symptoms that might indicate oral cancer include:^2,5

• A lump in the mouth or lip
• A neck lump
• Red and/or white patches in the mouth
• Unexplained Mouth ulcers
• Difficulties with speech
• Difficulty swallowing 
• Weird sensations in and around your mouth

These symptoms may also be prevalent with general symptoms such as weight loss and loss of appetite. 

Management and treatment for oral cancer

If you show symptoms of oral cancer it is best to go to the GP as soon as possible who will listen to your symptoms and perform an examination to get a better idea of what the problem may be. If your symptoms indicate a potential oral cancer you will be referred to a specialist via the 2-week waits for cancer pathway. ⁽⁶⁾ It is possible you may undergo a procedure called a flexible nasal endoscopy. This is a procedure where a camera is inserted into your nostril to get a better view of potential cancer. A biopsy of the tumour will be needed to diagnose. ⁽⁷⁾ Staging will be done using either an MRI or CT scan which will allow the healthcare team to have an indication of the extent of cancer and whether or not it has spread anywhere.⁷

Treatment of oral cancer is dependent on the size, and location. Generally, they are treated with surgery to remove the tumour. In some cases, surgery may be all that is needed however chemotherapy and/or radiotherapy remain an option either to treat cancer without surgery in certain situations or post-surgery to prevent a recurrence.⁸ Chemotherapy is where anticancer drugs are used to kill cancer cells. Radiotherapy uses radiation to target and kill cancer cells.

FAQs

How is oral cancer diagnosed

Oral cancer is diagnosed using a fine needle biopsy. This is where a needle is inserted into the suspected cancer and a small sample is taken. This is then sent to a laboratory to determine whether cancer cells are present in the sample

How can I prevent oral cancer

There are a few ways you can prevent oral cancer. Firstly avoiding, reducing and quitting smoking can reduce the risk as tobacco smoking is a considerable risk factor. Similarly reducing alcohol intake can also lower your risk of oral cancer. Taking the HPV vaccine also decreases the risk. In the UK there is a national HPV vaccine programme that initially was only for girls aged 12-13 however boys aged 12-13 have recently been included. If you are a woman born after 1 September 1991 or a man born after 1 September 2006 and missed out on vaccination the vaccination is still free on the NHS until your 25^th birthday.⁹ If you do not fit these criteria  you can still have the vaccine but you will have to pay a fee. Reducing the number of sexual partners may also prevent oral cancer. 

What are the stages of oral cancer

The stages of oral cancer are¹⁰

•  Carcinoma in situ or stage 0- This is very early
•  Stage 1 - Cancer is 2cm or smaller and 5mm deep
• Stage 2 -  Cancer is either 2cm or smaller but between 5-10mm in depth or between 2-4cm in size and less than 10mm in depth
• Stage 3 – Cancer is between 2-4cm large but more than 10mm deep and has not spread to any lymph nodes, is greater than 4cm but not deeper than 10mm with no spread to lymph nodes, or any size cancer where it has spread to a lymph node on the same side that is less than 3cm in size
• Stage 4 – Typically means cancer begins to spread outside the mouth to other structures surrounding the mouth, spread to multiple lymph nodes or one large lymph node or to further places in the body such as the lungs

Who is prone to oral cancer?

• Those with a heavy smoking History
• Heavy alcohol use
• People who chew betel quid
• Those with a higher number of sexual partners
• Those who are over 45. Those who get HPV-positive cancer tend to be younger than those who are HPV-negative

When should I see a doctor

If you have unexplained lumps, ulcers, or masses in your mouth, lip, or throat, consult a physician. If you experience any voice hoarseness, unexplained red and white patches in your mouth or unexplained ulcerations. Generally, if you notice any changes around your mouth or throat it is best to see a doctor anyway.

Summary

Oral cancer is a subset of head and neck cancers and are generally preventable by avoiding tobacco smoking, alcohol abuse, the use of the HPV vaccine and having a lower number of sexual partners. See a doctor as soon as possible if you are experiencing symptoms that could indicate oral cancer.