Neoplasms Flashcards
Define neoplasm.
mass/tumour that is the result of neoplasia, not necessarily cancer, but that doesn’t mean it isn’t problematic
Define neoplasia.
process of abnormal cell growth and differentiation, results in a mass/tumour
What does benign mean?
- abnormal growth that is not malignant
- growth is uncontrolled but slow, may stop or regress
- cells are differentiated to some degree
- tumour is non-invasive
What does malignant mean?
- abnormal growth that is disorderly, rapid
- results in poorly differentiated cells (anaplasia)
- doesn’t stop, keeps growing, is invasive
What is cancer?
malignant tumour
What does the word carcinoma usually mean?
usually denotes a malignant tumour originating in epithelial tissue
ex. adenocarcinoma = malignancy in glandular epithelium
What does the word sarcoma usually mean?
usually denotes malignant tumour originating in mesenchyme
What does “oma” usually mean?
usually denotes a benign tumour
ex. osteoma = benign tumour in bone
What is the most frequently mutated gene in cancer? What does the gene normally code for?
TP53 gene, normally codes for a protein responsible for apoptosis, triggers cell death when DNA is damaged
What other three groups of genes can cause cancer if they are mutated? What do the proteins they code for normally do?
1) DNA repair genes - reads DNA code, looks for and fixes errors
2) proto-oncogenes - “go genes” proteins tell cells to divide, enhances cell division
3) tumour suppressor genes - proteins to stop cell division and growth
What is an oncogene?
Any gene that causes malignant growth.
How long does it normally take for a malignant tumour to be detected clinically? How big does the tumour have to be to be detected clinically?
10 years, 1 cm
How long does it take tumours to double in size?
100 days
What are the three ways cancers spread? Explain each.
1) extension and invasion - tumour grows, invades surrounding tissues, damages tissue to make room for self
2) seeding - piece of tumour breaks off, no longer local, normally occurs in body cavities
3) metastasis - cancer spreads distally via blood or lymph
What are two requirements needed for cancer to establish at a secondary site?
must be large and well-perfused
What are the most common secondary sites for cancer?
lymphatic tissue, liver, lungs, bones, brain
Explain the 3 stages of metastasis.
stage 1
- invades local tissue, uses enzymes to destroy adjacent tissue and make room for self
- eventually growing cells make contact with blood or lymph and get in
- embolus (group of malignant cells) eventually forms (normally broken up by turbulence)
- embolus is coated in platelets, protected from body’s defenses
stage 2
- embolus travels in blood or lymph
- reaches area of resistance (capillary bed)
- determines if site suitable, using cytokines, growth hormone, begins to grow
stage 3
- form new blood vessels (angiogenesis)
- cells here are same as primary site
How can you tell a primary site from a secondary site?
primary site is usually one growth, secondary site usually has multiple growths
How are tumours staged?
TNM system
T = size, T0 for no tumour up to 4 N = nodular involvement, not number of nodes, 0-3 M = metastasis? yes or no 0, 1
How are tumours graded?
- histology is studied in the lab
- subjective determination made of tumour’s progression
- scored I to IV meaning restrictive to extensive
- refers to progress locally
List and briefly explain six ways cancer can be treated.
1) radiation - high dose of radiation, generates free radicals that cause necrosis of cancer cells and healthy cells in area
2) chemotherapy - targets cell division and prevents/slows growth of cells, also targets malignant and healthy cells
3) surgery - minimal side effects but be sure to get it all!
4) immunotherapy - antigen used to stimulate body’s own immune response to target the malignant cells
5) hormone therapy - only works if tumour nurtured by hormones, either use an anti-hormone or provide hormone in high dose to desensitize
6) combination therapy - combination of any of the above
