neoplasia Flashcards
what is a neoplasm?
new abnormal growth
what is oncology?
study and treatment of tomours
describe the growth of a neoplasm/tumour?
uncoordinated and exceeds that of normal tissues
which 2 ways can neoplasms be classified?
- clinical behaviour
- histogenesis (tissue of origin)
tumours can be classified by clinical behaviour, what 2 types of clinical behaviour are there?
- benign
- malignant
which type of tumour, benign or malignant, are encapsulated?
benign
which type of tumour, benign or malignant, involve invasion/infiltration ?
malignant
which type of tumour, benign or malignant, involves metastasis?
malignant
which type of tumour, benign or malignant, has a slow growth rate?
benign
which type of tumour, benign or malignant, has a fast growth rate?
malignant
which type of tumour, benign or malignant, shows variable resemblance to the tissue of origin?
malignant
which type of tumour, benign or malignant, shows uniform cell shape/size?
benign
which type of tumour, benign or malignant, shows few mitoses?
benign
which type of tumour, benign or malignant, shows many mitoses?
malignant
what are the clinical effects of benign tumours?
lump/pressure/obstruction, +/- hormone secretion
how may benign tumours be treated?
local excision
how may malignant tumours be treated?
local excision, chemotherapy, radiation or all 3
how does radiotherapy work?
radiation of metastasis prevent spread
what is the name for a benign salivary gland tumour?
pleomorphic adenoma
what is the name for a malignant tumour of the oral mucosa?
squamous cell carcinoma
where is at particularly high risk of squamous cell carcinomas ?
tongue
a benign squamous epithelial tumour is known as a?
papilloma
a malignant squamous epithelial tumour is known as a?
squamous cell carcinoma
a benign glandular epithelial tumour is known as a?
adenoma
a malignant glandular epithelial tumour is known as a?
adenocarcinoma
are squamous cell papillomas benign or malignant?
benign
what is the name for an epithelium malignancy?
carcinoma
sarcoma indicates what?
malignancy
a malignant smooth muscle tumour is known as a?
leiomyosarcoma
a benign smooth muscle tumour is known as a?
leiomyoma
a malignant fibrous tissue tumour is known as a?
fibrosarcoma
a benign fibrous tissue tumour is known as a?
fibroma
a malignant bone tumour is known as a?
osteosarcoma
a benign bone tumour is known as a?
osteoma
a malignant cartilage tumour is known as a?
chondrosarcoma
a benign cartilage tumour is known as a?
chondroma
a malignant fat tumour is known as a?
liposarcoma
a benign fat tumour is known as a?
lipoma
a malignant BV tumour is known as a?
angiosarcoma
a benign BV tumour is known as a?
angioma
what is a carcinogen?
substance that causes or can cause cancer
give some examples of carcinogens?
- chemicals (drugs, asbestos, smoking)
- physical agent (UV light, radiation)
- viruses (DNA/RNA viruses)
chemical carcinonogenesis is a 3 stage process what are the 2 stages?
- initiation
- promotion
- progression
what happens during the initiation stage of carcinogenesis?
carcinogen induces permanent DNA damage (mutation)
what happens during the promotion stage of carcinogenesis?
another factor promotes proliferation of initiated cell
what happens during the progression stage of carcinogenesis?
additional mutation resulting in malignancy
during carcinogenesis, the time between the promotion and formation of the clinical tumour is known as what?
latent period
what occurs during the latent period of carcinogenesis?
more mutations
most carcinogens are pro-carcinogenic, what does this mean?
require metabolic activation
what are co-carciogenic carcinogens?
substance promotes the effect of carcinogens but is not carcinogenic omits own
carcinomas are cancers of which area?
skin, lungs, breasts, pancreas, and other organs and glands
lymphomas are cancers of which cells?
lymphocytes
sarcomas are cancers of which area?
bone, muscle, fat, bloodvessels, cartilage, or other soft or connective tissues
give examples of the ateology of mouth cancer?
- tobacco
- betel quid
- alcohol coupled with tobacco
- diet and nutrition
- oral hygiene
- HPV
- immundeficieny
- socioeconomic factors
what is leukoplakia?
white patch on oral mucosa that can’t be removed, potentially malignant
name 4 important genes in carcinogenesis?
- oncogenes
- tumour supressor genes
- dna repair genes
- miRNAs
what are oncogenes?
genes which in certain circumstances can transform a cell into a tumour, mutated proto-oncogenes
what is the name for genes which regulate cell division?
proto-oncogenes
what is an oncogene in relation to a photo-oncogene?
oncogene are mutated proto-oncognes
what do oncogenes produce
oncoporteins
what are tumour suppressor genes?
genes that inhibit cell division and suppress growth
which genes act as anti-oncogenes?
tumour supressor genes
briefly describe what is meant by the knudson 2 hit hypothesis in relation to tumour suppressant genes?
in order for a cell to become cancerous, both of the cells tumour suppressant genes must be mutated
in order for a cell to become mutated, how many of a cells oncogenes have to be mutated?
1
give an example of a tumour suppressant gene
retinoblastoma
give examples of inherited factors which may cause cancer
single mutant gene, tumour suppressant genes, retinoblastoma
give 3 examples of familial cancers
- breast
- ovary
- colon
what is p53?
tumour suppressant protein
how is p53 activated and what function does it have?
- activated by damaged DNA
- if the DNA damage is repairable, it will stop the cell cycle and repair it
- if DNA damage is unreparibale it will induce apoptosis in that cell
how may p53 cause cancer?
if p53 is inactivated by deletion or mutation
name 6 hallmarks of cancer
- destruction tissue and metastasis
- avoid apoptosis
- sustained angiogenesis
- self-sufficiency in growth signals
- insensitivity to antigrowth signals
- limitless replicative potential
how may malignant tumours spread?
- locally
- lymphatic spread
- blood spread (haematogenous)
- tratscelonic spread
- intraepithelial spread
what is metastasis?
spread of malignant cells to distant organs forming secondary tumours
how do carcinomas tend to spread?
- lymphatic spread
- blood spread (haematogenous)
how do sarcomas tend to spread?
blood
describe the metastatic process/cascade
- invasion of cancer cells through basal membrane into lymphatic vessel of blood
- survival in circulation
- arrest in organ
- extravasion - leave circulation and enter organ
- survival after extravasion
what is tumour grading?
histopathologicslly assessing the biological nature of the tumour
what is tumour staging?
clinically assessing the extent of spread
which piece of equipment is usually used for tumour grading?
microscope
cells of a malignant tumour may show?
- pleomorphism (variation in shape/size)
- numerous mitoses
- abnormal mitoses
- variable differentiation
tumour staging and grading help with what?
planning of treatment plan
give examples of some systemic effects of cancer?
- fever
- anorexia
- cachexia
- neurological problems
- endocrine problems
- metabolic effects
give 3 types of cancer surgery
- radiotherapy
- chemotherapy
- surgery
which molecules allow the immune system to recognise tumour cells?
- tumour associated antigens
- products of mutated genes
- over expressed proteins
- viral proteins
- oncofetal antigens
how can the immune system eliminate tumour antigens?
elimination by cell mediated immune responses:
- CD8 T cells
- NK cells (1st line defence against tumour)
- macrophages
how do tumour cells evade the immune system?
- alter tumour antigen expression to lack t cell recognition
- activate immunoregulatory pathways to inhibit t cell response and apoptosis
- immunosupprsant factors (cytokines) to inhibit t cells
what does immunotherapy involve?
use patients immune response to control and destroy malignant cells
immunotherapy is most successful in which type of malignancies?
haematological
what is the main risk factor for oral cancer?
tobacco
name the 3 stages of carcinogenesis?
- initiation
- promotion
- proliferation
