ORAL SQUAMOUS

CELL CARCINOMA

Preethi Agnes.R

B.D.S 2012 Batch

DEFINITION It is a Malignant neoplasm of stratified

squamous epithelium in the oral cavity capable of local destructive growth and

distant metastasis

INCIDENCE Possible sites    

lower lip  tongue floor of the mouth    soft palate        gingival / alveolar ridge    buccal mucosa

Incidence

lower lip

tonguefloor of mouth

soft palate

gingiva

buccal mucosa

ETIOLOGY The etiology is unknown. But a

number of etiological factors have been implicated.

Strong Association:• Tobacco smoking and chewing• Chronic alcohol consumption • Human papilloma virus infection

TOBACCO Major source of intra-oral carcinogen. All forms of tobacco consumption have

been linked. South east Asia: bethel quid– North Africa

and Middle East: a mixture of Tobacco and lime water or oil called naswar or nash

It could be held in the mouth Smoked in crude cigars or factory made

cigarettes Carcinogens in tobacco: Nitrosamine

(nicotine), the polycyclic aromatic hydrocarbons (3,4-benzopyrene)

ALCOHOL 2nd major risk factor Associated with cancer of the floor of the

mouth and tongue. Excess consumption of EVERY TYPE of

alcohol(including “hard” liquor, wine, and Beer) raises the risk status of oral cancer

Potentiates the effects of tobacco Mechanism(s)

Dehydrating effects of alcohol on the mucosa increasing mucosal permeability, Irritation of mucosa and it also acts as a solvent for

carcinogens(especially those in tobacco)

ETIOLOGYWeak association: Chronic irritation from ill-fitting

denture Sub mucosal fibrosis Poor orodental hygiene Nutritional deficiencies Exposure to sunlight(lip cancer) Plummer –Vinson syndrome

PATHOGENESIS NEOPLASIA:The process of

transformation from a normal cell to a cancerous one.

An abnormality of cell growth and multiplication characterised by:

At cellular level Excessive cellular proliferation Uncoordinated growth Tissue infiltration

At molecular level Disorder of growth regulatory genes

NEOPLASTIC (malignant) CELLS

Increasein growth factors

Increasein growth factorreceptors

Increase in signal transduction

Increase in activation of transcription

- Disturbed processes of mitosis and protein synthesis

MALIGNANT CELLS Continuous reproduction

Formation of abnormal proteins

ANAPLASIA: loss of normal cell function (abnormal DNA transcription) proliferation movement of cells invasion of nearby tissue metastasis

Caused by altered DNA and altered cellular programs which make new signals

HYPOTESIS OF THE ORIGIN OF NEOPLASIA two general types

Monoclonal initial neoplastic change affects a single cell

Field origin carcinogen acts on large number of cells

producing field of potentially neoplastic cells

REGULATORY GENESPROTO-ONCOGENES

growth factors receptors signal-relay or

transduction factors ras - colon cancer myc - lymphoma bcr-abl - chronic myelogenous leukemia (Philladelphia chromosome)

TUMOR SUPPRESSOR GENES- code for factors that down- regulate the cell cycle, promote differentiation and supress oncogenes from causing cancer Rb-1 – retinoblastoma gene p53

NEOPLASIA proto-oncogene is activated or tumor suppressor gene is inactivated

normal growth oncogenesis

Activation of proto-oncogene: point mutationtranslocationgene amplification

Also - Failure of Immune Surveillance theory : immune system responds to neoantigens as to foreign antigens, but neoplastic cells escape recognition and destruction --> become clinical cancers

HEREDITY Transmission of some forms of cancer from parents to

offspring through defects in the DNA of the egg or sperm cells

E.g. Retinoblastoma – tumor of the retina of the eye Polyposis coli syndrome – polyps that grow in

the colon and

rectum Other colon, breast and kidney cancers

Cause: loss of a segment of DNA or a change in the coding sequence of DNA Detection – DNA sequencing, DNA probes

In many cases – abnormalities in tumor suppressor genes

CLINICAL FEATURES  A sore in the mouth that does not heal

(most common symptom) Pain in the mouth A persistent lump or thickening in the

cheek A persistent white or red patch on the

gums, tongue, tonsil, or lining of the mouth

A sore throat or a feeling that something is caught in the throat

Increased salivation

CLINICAL FEATURES  Difficulty chewing or swallowing Difficulty moving the jaw or tongue Swelling of the jaw that causes dentures

to fit poorly or become uncomfortable Loosening of the teeth or pain around

the teeth or jaw Voice changes A lump or mass in the neck Weight loss Persistent bad breath

MACROSCOPICAL FEATURES Grossly, squamous cell carcinoma of

oral cavity may have the following types: Ulcerative type Papillary or verrucous type Nodular type Scirrhous type All these types appear on a background of

leukoplakia or erythroplasia of the oral mucosa.

Enlarged cervical lymph nodes may be present.

HISTOPATHOLOGICAL

Increased mitotic activity Well differentiated   Keratin pearls (abnormal keratinization)   Hyperchromatic nuclei   Pleomorphism Epithelium islands Connective tissue stroma with chronic

inflammation (histiocytes, lymphocytes, etc.)

Keratinized cells

Mitotic figures

Inflamed connective tissue stroma

LAB INVESTIGATIONS  Primary:

Photographs Incisional biopsy Fine needle aspiration biopsy Orthopantogram Mucosal staining CXR chemiluminescent light Routine blood investigations

 For staging MRI CT face + neck ± CT chest USG of neck or primary ± USG guided FNAC of suspicious

lymphadenopathy PET Endoscopy

TREATMENT Surgery

Removal of part or all of the jaw Removal of the tumor on a larger area to remove the

tumor and surrounding healthy tissue Maxillectomy Removal of lymph nodes and other tissue in the neck Plastic surgery, including skin grafts, tissue flaps or

dental implants to restore tissues removed from the mouth or neck

Tracheotomy, or placing a hole in the windpipe, to assist in breathing for patients with large tumors or after surgical removal of the tumor

Dental surgery to remove teeth or assist with reconstruction

Radiation Therapy -used alone to treat small or early-stage

tumors. Proton Therapy  -delivers high radiation doses directly into the

tumor, sparing nearby healthy tissue and vital organs.

Chemotherapy -used to shrink the cancer before surgery or

radiation  Tumor Growth Factor Inhibitors  -target EGF receptors and may stop cancer

cells from growing.

COMPLICATIONS  Mucositis ,an inflammation of the mucous

membranes in the mouth. Infection, pain, and bleeding Dehydration and malnutrition due to dysphagia Xerostomia due to injury to the glands that

produce saliva. Trismus due to damage to the muscles and joints

of the jaw and neck. Hypovascularization (reduction in blood vessels

and blood supply. Affect other forms of dental disease (caries, or

soft tissue complications), Cause bone death (osteonecrosis).

COMPLICATIONS Rehabilitation of patient after surgery

could be either surgical reconstruction, prosthetic reconstruction or both

This is aimed at restoring esthetics, function and speech.

All patients must be placed on life-long review of about 6monthly intervals during which risk factors should be continually assessed.

PREVENTION Prevention involves interventions aimed at

eliminating, eradicating or minimizing the impact of the disease.

 PRIMARY: Reduce the incidence of cancer and precancer. It is aimed reducing the number of new cases. Discourage smoking and alcohol consumption

Encourage good oral hygiene Encourage balanced diet Use of hat in sunlight for farmers Wearing of facemasks for factory workers

involved with chemicals and metals Health education

SECONDARY: aimed at detection of cancer atan early stage.

Early detection, especially at the precancerous stage, offers a better prognosis with a better chance of cure.Public education on early signs and self-

examinationScreening

TERTIARY: Treat late stage of disease and complications