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Oral Cancer - Pre-Malignant Lesions
Most oral cancers appear to arise in ‘normal’ oral mucosa but some are preceded by potentially malignant / pre-
malignant
clinically obvious lesions.

These include:







Conditions that MAY predispose to malignancy (ie oral cancer) include:

  • Lichenoid lesions + Lichenoid Dysplasia


  • Previous oral malignancy

  • Syphilitic Leukoplakia / Glossitis

  • Immunosupression

  • Dyskeratosis Congenita

  • Paterson-Kelly syndrome

  • Discoid Lupus Erythematosis

What are thought to be the lesions / conditions likely to cause malignancy are logically the same ones that cause
pre-malignancy.
Last Updated 1st January 2020
Actinic Cheilitis (AKA Actinic Keratosis of Lip, Solar Keratosis, Solar Cheilosis)

  • Occurs in adults & mainly men
  • Mainly seen in persons from the Tropics
  • Chronic pre-malignant keratosis of the lip caused by long exposure to solar irradiation.  Most is seen:
  • on the lower lip with sparing of the commissures
  • in fair-skinned men
  • 4 – 8th decade of life
  • outdoor jobs / activities
  • Early stages – erythema & œdema; later stages, the lip becomes dry, scaly & wrinkled with grey / white
    changes in pigmentation.  Lesions appear as a smooth or scaly, friable patch or even the whole lip.  Later still,
    the lip becomes thickened with small greyish-white plaques with even warty nodules forming
  • Prevention with sunblocks
  • Treatment with topical chemo-exfoliants & surgery
Erythroplasia / Erythroplakia (AKA Red Patch)

  • Occurs in the middle aged & the elderly & mainly in men
  • Less common than leukoplakia
  • Erythroplakia contains areas of dysplasia, carcinoma in situ or invasive carcinoma in virtually every case

Most potentially malignant of all oral mucosal lesions.

  • Red velvety patch of variable configuration, usually level / depressed with surrounding mucosa, commonly on
    the soft palate, floor of mouth or the buccal mucosæ
  • Some erythroplakias are associated with white patches & hence termed, speckled leukoplakias
  • Any causal factor, such as tobacco, should be stopped
  • Lesions removed followed by regular follow-ups
Leukoplakia (AKA White Patch)

  • Occurs in approx 1% of the population; men > women
  • Predisposing habits – tobacco, alcohol & betel use; sanguinarine use

  • Leukoplakia has a wide range of clinical presentations, from homogenous white plaques (faintly white – very
    thick & opaque) to nodular white lesions to lesions admixed with red lesions.

The malignant potential depends on appearance, site & some ætiological factors.

  • Appearancenon-homogenous / heterogenous leukoplakias has a high risk of malignant transformation

  • Site – soft palate complex, ventro-lateral tongue & FOM have a high risk of malignant transformation

  • Ætiology – virus (HPV, EBV), bacterial (syphilis) or fungal (Candida) have a high risk of malignant
    transformation

  • Any causal factor, such as tobacco, should be stopped.
  • Lesions removed followed by regular follow-ups.
  • Surgical / Medical treatment
Photos of Leukoplakias
Photo of Speckled Leukoplakia (arrowed)
Dysplasia seems to be the most predictive marker in use for malignant potential.


Factors Predictive of Future Malignant Transformation may include:

  • History of cancer of upper aero-digestive tract
  • Expression of P53 tumour suppressor protein
  • Changes involving chromosomes 3p or 9p; “Loss of HeterozygosityLOH
  • Chromosomal polysomy


Principles of Management of Dysplastic Lesions:

  • Stop any associated habits, eg betel quid or smoking
  • Treat any candidal infection and / or iron deficiency if present
  • Biopsy to assess dysplasia
  • Assess risk of pre-malignant change on clinical & histological findings
  • Consider ablation of individual lesions
  • Maintain observation for signs of malignant change


Options for the Management of Pre-Malignant Lesions:

  • Observation for early detection of cancer
  • Surgical excision with grafting (if required)
  • Cryotherapy
  • Laser excision / vaporisation
  • Topical chemotherapy (eg bleomycin)
  • Retinoids

Cryotherapy heals rapidly to leave an apparently normal mucosa.  However, there is some uncertainty about the
risk of
OSCC subsequently arising in these sites.

With
laser ablation, seemingly similar concerns.

Topical chemotherapy are largely ineffective and lesions that resolve, recur on cessation of the drugs.
Photo of Actinic Cheilitis
Photos of Actinic Cheilitis
Photos of Erythroplasia / Erythroplakia
Management of Leukoplakia
Useful Websites:

The Oral Cancer Foundation

The Mouth Cancer Foundation

Emedicine.com


Useful Articles:

BMJ 1999.  Oral Cancer

Dental Update 1999.  Update on Precancerous Lesions

CA Cancer J Clin 2002.  Oral Cancer and Precancerous Lesions

BDJ 2003.  Oral Cancer Prevention & Detection in Primary Healthcare

Critical Reviews in Oral Biology & Medicine 2003.  Prognosis of Oral Pre-Malignant Lesions - Significance of
Clinical, Histopathological & Molecular Biological Characteristics

Preventive Dentistry 2006.  Oral Cancer - A Growing Concern

Dental Update 2006.  Current Concepts in the Management of Oral Cancer

Canadian Family Physician 2008.  Clinical Review.  Screening for and Diagnosis of Oral Pre-Malignant Lesions and
Oro-Pharyngeal Squamous Cell Carcinoma.  Role of Primary Care Physicians

Oral Oncology 2008.  Oral Cancer Prevention and Control – The Approach of the World Health Organization

American Academy of Oral Medicine 2008. Patient Information Sheet.  Pre-Malignant Oral Lesions

Oral Oncology 2009.  Review.  Global Epidemiology of Oral and Oro-Pharyngeal Cancer

Head Neck 2009.  Treatment & Follow-up of Oral Dysplasia - A Systematic Review & Meta-Analysis

BJOMS 2011.  Management of Oral Carcinoma - Benefits of Early Pre-Cancerous Intervention

Dent Update 2015.  Mouth Cancer for Clinicians Part 5.  Risk Factors (Other)

Dent Update 2015. Mouth Cancer for Clinicians Part 6. Potentially Malignant Disorders

British Dental Journal 2018.  The Changing Epidemiology of Oral Cancer - Definitions, Trends & Risk Factors

British Dental Journal 2018.  Oral Cancer & Tobacco - Developments in Harm Reduction

British Dental Journal 2018.  The Pathology of Oral Cancer

Oral Surg Oral Med Oral Pathol Oral Radiol 2018.  Clinical Features & Presentation of Oral Potentially Malignant
Disorders
Management of Potentially Malignant Lesion