Neoplasia Flashcards
What is meant by neoplasm?
Genetic disorder of cell growth, tumour
What are characteristics of a benign tumours growth pattern?
-may be encapsulated
-expansion
-localised
What are characteristics of a malignant tumours growth pattern?
-Invasion/infiltration
-no capsule
-metastasis (can travel to other organs)
What are the histological features of a benign tumour?
-resembles tissue of origin
-uniform cell/nuclear shape and size
-few mitoses (dividing cells)
What are the histological features of a malignant tumour?
-variable resemblance to tissue origin
-different shape sizes/nuclear sizes
-many mitoses
What are clinical effects of benign tumours?
-Lump/pressure/obstruction depending on site and size
-+-hormone secretion
-treat by local excision
What are clinical effects of malignant tumours?
-local pressure, infiltration and destruction
-+- hormone secretion
-local excision and chemotherapy or radiation if metastases present
What is an example of a benign tumour which effects the salivary gland?
Pleomorphic adenoma
What does the term adenoma mean?
A tumour arising from glandular tissue
Where is a high risk area for cancer in the oral cavity?
Tongue
What two components are all tumours composed of?
-Neoplastic cells that constitute the tumour parenchyma
-Reactive stroma made up of connective tissue, blood vessels, and cells of the adaptive and innate immune system.
What does term ‘sarcoma’ mean?
Malignant CONNECTIVE TISSUE tumour
What does term ‘carcinoma’ mean?
Malignant EPITHELIAL TISSUE tumour
What is leukoplakia?
White patches in the mouth that cannot be rubbed off
What epithelial tissues may dysplasia effect?
Squamous - oral, cervical
Glandular - Barret’s oesophagus
Transitional- Bladder
What is meant by pleomorphism?
Different shapes and sizes
How is dysplasia identified?
A change in the cells appearance and arrangement
What HPV types are the most likely to be associated with malignancy?
HPV 16 and 18
What are the stages of carcinogenesis?
Initiation- when carcinogen induces a genetic change in one cell
Promotion- another factor stimulates the initiated cell for division
Progression- Additional mutations resulting in malignancy.
What are examples of chemical carcinogens?
-smoking polycyclic hydrocarbons including tars
-diet, drugs, alcohol
-asbestos
What are examples of physical carcinogenesis?
-Ionising radiation
-UV light
What are proto-oncogenes?
Normal genes which regulate cell division
What are tumour suppressor genes?
Genes which act to inhibit cell division and suppress growth
Act as anti-oncogenes
What is the function of TP53 gene?
Stop the cell cycle to allow DNA repair
Apoptosis
What are examples of inherited cancer syndromes?
Retinoblastoma
Colon cancers
What are examples of familial cancer?
Breast, ovary, colon
What are 6 hallmarks of cancer? !
-Evade apoptosis
-Sustain angiogenesis
-Tissue invasion and metastasis
-limitless replicative potential
-Self sufficiency in growth signals
-insensitivity to anti-growth signals
What are different ways malignant tumours can spread?
Local
Lymphatic spread
Blood spread
Transcoelomic spread
Intraepithelial spread
What is metastasis?
Spread of the malignant cells to distant organs forming secondary tumours
How are carcinomas usually spread?
Lymphatic
Blood (later)
How do sarcomas usually spread?
Blood
How is tumour grading performed?
By looking at tissue with microscope and investigating tissue to notice any changes
What is cancer staging?
Staging describes the extent or severity of a person’s cancer. Knowing the stage of disease helps planning treatment and estimating the person’s prognosis.
How does the immune system recognise tumour cells?
-products of mutated genes
-Viral proteins
-Overexpressed proteins
What cell drives the immune response to tumour associating antigens?
Cytotoxic T-lymphocytes (CD8+)
How do tumour cells evade the immune response?
-Alter tumour antigen expression. Lack of T cell recognition
-Activation of immunoregulatory pathways leading to T cell unresponsiveness and apoptosis
-Immunosuppressive factors (cytokines). Inhibit t cell response
What is immunotherapy?
Using the patients own immune response to control and destroy malignant cells
