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Facts about the skin from DermNet New Zealand Trust. Topic index: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z



Oral cancer

There are several types of oral cancers, but over 90% are squamous cell carcinomas. Worldwide, oral cancer is one of the ten most common sites of cancer. People all over the world are affected but it appears to occur most frequently in developing countries particularly India, Pakistan and Bangladesh. In fact, in some parts of India, oral cancer accounts for more than 50% of all cancer.

Who gets oral cancer and why?

Oral cancer usually occurs in people over the age of 40. It is twice as common in men as in women.

Risk factors for developing oral cancer include:

What are the signs and symptoms?

Many oral cancers are only detected when they are well advanced. Often in the early stages the cancer is painless and may go unnoticed. This has led to a high mortality rate compared to cancers of other sites. Thus, the early recognition of signs and symptoms of oral cancer is very important. These include:

Oral cancer
Cancer of the inner lip

The most common sites of oral cancer are the lower lip, tongue and the floor of the mouth, although any part of the mouth may be affected. Between 30 and 80% of patients with oral cancer also have secondary lesions (metastases) in the cervical lymph nodes at presentation. At a later stage, cancer may spread to regional lymph nodes, lungs, liver or bones.

Diagnosis and staging of oral cancer

Biopsy of the lesion is performed to get an accurate diagnosis. Dr Philippe Abimelec's video shows how this is done.

After initial diagnosis of oral cancer, the stage of cancer will be determined. This will define the size of the tumour, how deeply the tumour has invaded tissues at the site of origin, and the extent of any invasion into surrounding organs or lymph nodes. Determining the cancer's stage is an important factor as it directs treatment planning. The 1993 American Joint Committee on Cancer TMN classification and staging of oral cancer is commonly used.

Classification of oral cancer
Primary tumour T0 No primary tumour
Tis Carcinoma in situ
T1 Tumour 2 cm or less
T2 Tumour 4 cm or less
T3 Tumour >4 cm
T4 Tumour >4 cm and deep invasion into muscle, bone, deep structures
Lymphatic node involvement N0 No nodes
N1 Single homolateral node <3 cm
N2 Node(s) homolateral <6 cm
N3 Nodes(s) >6 cm and/or bilateral
Tumour metastasis M0 No metastasis
M1 Metastasis noted


Staging of oral cancer
Stage I T1, N0, M0
Stage II T2, N0, M0
Stage III T3, N0, M0
T1, T2, T3, N1, M0
Stage IV T4, N0, M0
Any T, N2 or N3, M0
Any T, any N, any M

What is the treatment of oral cancer?

Treatment of oral cancer depends on the type of cancer and the stage of the cancer. In general, diagnosis and treatment during the early stages of cancer have a much better outcome. Oral cancer squamous cell carcinoma is generally treated by surgery and/or radiation therapy. Chemotherapy may also be used, particularly in patients with confirmed metastases to other tissues and organs.

Oral health needs are addressed prior to cancer therapy. This is to minimise oral disease and post-therapeutic complications. It appears that up to 97% of patients require oral healthcare before treatment of cancer can begin. Some of the complications that may occur post cancer treatment are radiotherapy- or chemotherapy-induced mucositis (inflamed mouth), oral ulceration, bleeding, infections, pain, xerostomia (dry mouth) and caries (holes in the teeth).

Surgery is aimed at removing the primary tumour and some of the surrounding normal tissue to make sure the cancer has been completely removed. If done during the early stages of cancer there is usually little or no post treatment disfigurement. Surgery performed at later stages may also require reconstruction of parts of the mouth or face.

Related information

References:

Book: Textbook of Dermatology. Ed Rook A, Wilkinson DS, Ebling FJB, Champion RH, Burton JL. Fourth edition. Blackwell Scientific Publications.

On DermNet NZ:

Other websites:

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Author: Vanessa Ngan, staff writer

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