Management of Potentially Malignant Disorders

Question 1

When is the prognosis of oral carcinomas good?

Answer 1

When the diagnosis is made early and the tumour is small

Question 2

What are the principles of management of OPMDs?

Answer 2

• Stop any associated habits
• Dietary intervention
• Treat candida infection and/or iron deficiency
• Biopsy to assess dysplasia (help make early diagnosis)
• Assess risk of malignant transformation on clinical and histological findings
• Consider ablation of individual lesions
• Maintain observation for signs of malignant change

Question 3

What clinical clues help assess risk of malignant change of a OPMD?

Answer 3

1. History
   - Habits
   - Nutrition
   - Disease
   - Genetic disorders
   - Previous oral cancer
2. Clinical aspects
   - Advanced age
   - Female
   - Areas of reddening, speckling in the lesion
   - Nodular or verrucous areas of ulceration
   - High risk sites (poterolateral tongue, FOM, retromolar lesions)
   - Large lesions
   - Lesions present for long periods
   - Enlargement or change in character of lesion

Question 4

How can you clinically assess a OPMD

Answer 4

• Examine mouth
• Palpate cervical lymph nodes in case of metastasis
• If lesion, record size, colour, homogeneity, if areas of nodular or verrucous changes, ulceration, redness or speckling, site, induration
• Photographic record to monitor changes

Question 5

What adjuncts to clinical diagnosis can be used to help assess malignant transformation risk

Answer 5

• Tolonium chloride rinsing and brush biopsy (make dysplastic lesions more identifiable on clinical examination)
• Chemiluminescence: illuminate the mucosa with wavelength of light that is usually absorbed but reflected by abnormal lesions
• Others use auto-fluorescence patterns or more complex laser reflectance

Question 6

How can the results of a biopsy help assess malignant transformation risk

Answer 6

• Excludes or confirms whether carcinoma is present and allows dysplasia to be detected
• Every white or red patch in mouth should be biopsied but some lesions in practice can allow confident diagnosis of benign lesion (e.g. stomatitis nicotina) and response to tx may avoid biopsy (e.g. chronic hyperplastic candidosis responding to anti fungal tx)
• Selection of correct site is critical
  1. biopsy must include highest risk areas (those with erythema or speckling)
  2. take biopsy from margin (avoid centre)
  3. More than one biopsy may be necessary

Question 7

What is dysplasia?

Answer 7

• Means only growth disturbance and is used in other names of benign conditions (e.g. fibrous dysplasia or cement-osseous dysplasia). It is only epithelial dysplasia that indicates potential malignancy
• Best indicator of risk transformation to carcinoma
• The more abnormal the epithelium, the higher the risk of carcinoma developing

Question 8

Are all the features of dysplasia seen in a carcinoma?

Answer 8

• yes the only difference between the two is the way the tissues are arranged
  1. in dysplasia, the structure of epithelium is retained but deranged
  2. in a carcinoma, epithelial cells no longer form a covering layer but invade the underlying connective tissue

Question 9

What are the features of mild dysplasia?

Answer 9

• Basal cells show slight disorganisation
• Increased proliferation with several layers of basaxoid cells with large nuclei, and among them are scattered cells with very abnormal shape or size

Question 10

What are the features of moderate dysplasia

Answer 10

• Changes extend to mid height of epithelium
• Disorganised appearance in the basal layers
• More layers of basaloid cells
• Increased intercellular spaces as a result of loss of cohesion
• Abnormal mitoses
• Abnormal cells may be seen

Question 11

What are the features of severe dysplasia?

Answer 11

• Changes through most of the epithelial thickness
• The features are almost those of carcinoma, only invasion is missing
• Cells with most marked abnormalities
• Loss of the layered structure of the epithelium
• Mostly occupied by basal type cells
• Loss of cohesion

Question 12

What are the features of more severe dysplasia?

Answer 12

= Carcinoma in situ

- Dysplastic changes through all basal layers to surface

Question 13

How does dysplasia grade relate to transformation?

Answer 13

• Despite the fact that dysplasia is the best indicator of transformation, the exact relationship between grade and transformation is ill defined. Any grade signifies some risk
• Severe dysplasia is more at risk of carcinoma developing more quickly

Question 14

What happens to the dysplasia lesions that do not transform to cancer?

Answer 14

Some resolve, some stay unchanged and others may remain and constitute a risk over an even longer period

Question 15

Which molecular investigations can be done that might be better predictors of malignant transformation than dysplasia grading?

Answer 15

• Able to detect risk when dysplasia is not present
  1. Detecting abnormalities in chromosome numbers and loss or gain of function of genes is relatively easy, but no marker has yet proved a good predictor
  2. DNA ploidy analysis: a measure of total nuclear DNA content using dye. Dysplastic and malignant cells show chromosomal instability, and changes can be detected in epithelium that does not show dysplasia

Question 16

Why is the management of OPMDs controversial

Answer 16

• Because malignant transformation has serious consequences fo the pt, but in the vast majority will never transform
• Would the resultant morbidity and costs of tx of all cases outweigh the risk of cancer in a few?

Question 17

How can low risk lesions be managed?

Answer 17

• Pt risk factors must be addressed: smoking cessation advice, alcohol moderation or other habit intervention
• Candida infection should be eliminated: topical and systemic (fluconazole)
• Change in lesions is suspicious: detect using photographs/diagrams
• Dietary intervention: insufficient fruit and vegetables are known risk factor for oral carcinoma
• Eliminate trauma

Question 18

How can high risk lesions be managed?

Answer 18

• All the management for low risk
• Can observe closely, in hope of detecting carcinomas as early as possible (where tx options are much clearer cut)
• Lesions may be ablated by:
  1. Surgical excision, with grafting if required
  2. Laser excision: well tolerated and heals well with limited scarring
  3. Other less successful techniques: Laser vaporisation, photodynamic therapy, cryotherapy
• In the absence of alternative treatments, surgical excision remains the tx of choice for high-risk lesions, but recurrence of as many as 30% is reported

Question 19

Why can it be difficult to excise lesions?

Answer 19

• Surgical excision of large lesions carries morbidity. Visible musical changes are seen in only parts of the genetically altered field, making excision of the entire potentially malignant area impossible. Only areas of highest risk can be removed
• Difficult to remove lesions in highest risk areas e.g. posterior FOM
• An attempt is usually made to excise all small lesions with moderate dysplasia and any lesions with severe dysplasia. After excision, follow up required as carcinoma may not develop for 10 years or more. Monthly appts for 2 years are gradually extending appt intervals if lesions unchanged, habits and diet addressed and pt educated about risk