Cancer - The Disease and How It's Treated

What are the characteristics of benign tumours?

What are the characteristics of benign tumours?

• Remain localised

• Slow growing

• Do not invade/spread

• Histologically resemble the parent cell or tissue

• Minimal nuclear changes

What are the characteristics of malignant tumours?

PHIRM D

1. Penetrate the walls of blood vessels, lymphatic channels and other parts of the body

2. Histologically resemble the parent cell to a lesser extent

3. Invasive

4. Rapidly growing with irregular margins

5. Metastasis

6. Destroy the adjacent tissue

What are some of the clinical problems associated with benign tumours?

1. Pressure on adjacent site

2. Obstruction (of flow/fluid/air)

3. Increased production of hormones

What three features can be used to identify a benign or malignant lesion?

Most benign and malignant tumours can be distinguished based on the evaluation of three features:

• Degree of differentiation (benign = more, malignant = less)

• Local invasion

• Metastasis

What is the meaning of anaplasia?

having no functional capabilities.

describes malignant cells

What are the features of anaplastic cells?

P PLAIN

1. Pleomorphism- variation in cell size and shape between the cells.

2. Prominent nucleoli

3. Loss of polarity- loses its orientation.

4. Atypical Mitosis- division of the nucleus without division of the cytoplasm.

5. Increased nuclear-cytoplasmic ratio (large nuclei).

6. Nuclear Abnormalities- nuclear hyperchromatism

What is dysplasia?

• abnormal arrangement of cells or atypical cell development

• may become precursor lesions to cancer.

What are features of dysplasia?

o   Cellular and nuclear pleomorphism.

o   Abnormal mitotic activity (no longer just confined to the basement membrane).

o   Architectural disarray (the basement membrane has ill defined, bulbous rete ridges, it may also be stratified rather than one cell thick).

Do all dysplastic lesions progress into cancer?

not always but there is a risk

shows that its best to identify lesions at precancerous stage

What is metastasis?

spread of a tumour to sites that are physically discontinuous with the primary tumour

If a tumour can metastasize = malignant.

Anaplastic lesions are more likely to metastasize

What are the three pathways of metastatic spread?

Seeding within body cavities- is particularly characteristic of ovarian carcinomas which often spread along the peritoneal surface.

Lymphatic Spread- Typical spread pathway of carcinomas

Bloodstream- Favoured pathway for sarcomas.

How do invasion and metastasis occur?

result from complex interactions involving cancer cells, stromal cells, and ECM

carcinoma must first invade the underlying basement membrane and transverse the interstitial connective tissue.

BREAKAGE of the basement membrane converts a dysplastic lesion to a malignant lesion

gains access to the circulation by penetrating the vascular basement membrane

What examinations can be done to diagnose cancer?

Physical exam

e.g see if there any symptoms from patient, palpating nodes

Radiographic exam

CT, MRI, FDG-PET

Biopsy and lab investigations

What are the benefits of a multidisciplinary team in oral cancer diagnosis?

• Improved communication between providers

• Improved treatment outcomes

• Pre-treatment dental examinations

What is most accurate method of detecting squamous cell carcinoma?

biopsy (needs LA)

What are the 2 types of biopsy?

• Incisional Biopsy = removal of a representative tissue of a lesion

• Excisional Biopsy = complete removal of the lesion with a border of normal tissue (for very small lesions)

How do we take biopsy of pts on anticoagulants?

Exfoliative Cytology- Minimally invasive technique for obtaining oral cell specimens

Fine Needle- A needle is introduced into a lesion. The cytologic material is aspirated and stained.

What does it mean by grading of cancer?

Based on the degree of differentiation of the tumour cells. How much does it resemble the tissue of origin?

What does staging of cancer mean?

Is based on the size of the primary tumour, the extent of its spread to regional lymph nodes and the presence/absence of metastasis.

What is TNM staging?

TNM Staging:

• T: The size of the primary tumour (T1-T4)

• N: Node involvement (N0-N3)

• M: Metastasis (M0 or M1) where M0 = no metastasis.

What does the surgery of early stage tumours involve specifically oral squamous cell carcinoma?

GOAL = complete resection of tumour (cut out)

AVOID RADIAITION - risk of osteonecrosis

May dissect the neck to check for involvement of metastasis (hidden) in regional lymph nodes - RISK OF NERVE AND VESSEL DAMAGE

If it is in nodes = dissection of lymph nodes

How is radiotherapy used for oral cancer?

not usually done - risk of osteonecrosis

usually done additionally to assist success in surgery

What are some of the side effects of radiotherapy?

• Tiredness

• Feeling sick

• Difficulty eating and drinking

• Skin reaction

• Hair loss

• Haematological changes

• xerostomia

What are the aims of bone reconstruction?

• Restoration of the bony contour

• Restoration of the soft tissue thickness

• Epithelial coverage to the defect area

Microvascular free-tissue transfer has become standard in head and neck reconstruction

What is salvage surgery?

surgical treatment after failure of initial treatment- local recurrence, lack of response after adequate management of cancer

What is targeted cancer therapy?

The identification of a specific receptor which would lead to destruction of the tumour e.g. via necrosis or activation of the immune system, so that they recognise the cancer cell as foreign