Patho - Cancer Flashcards
What is the Big 3 cancer for men?
- colorectal
- lung
- prostate
What is the Big 2 cancer for woman?
- colorectal
- breast
Gross features of Benign Neoplasm
- Smooth surface with fibrotic capsule -> encapsulation
- Well-circumscribed (well circumscribed does not mean encapsulated)
- No necrosis
Gross features of Malignant Neoplasm
- Irregular surface without encapsulation -> tumour tissue infiltrate with non-tumour tissue (poorly demarcated from surrounding tissue)
- Necrosis and haemorrhage
- multi-focal (many lesions present)
- pale discolouration
- poorly circumscribed
Microscopic features of Benign Neoplasm
- Compression of other cells
- Highly differentiated -> resemble original tissue
- Cells are normal, resembles one another -> uniform appearance
- Few mitoses
- Well-formed blood vessels
- No necrosis
- No metastasis
Microscopic features of Malignant Neoplasm
- Invasion of other cells
- Poorly differentiated -> do not resemble original tissue (anaplasia)
- Cells are abnormal
- enlarged hyperchromatic
- high N:C ratio
- irregular nuclei with large nucleoli
- clumped chromatin irregularly distributed
- variation in size and shape (pleomorphism) - Increase & abnormal mitotic activity
- Poorly formed blood vessels
- Necrosis and haemorrhage
- Metastasis to distant sites
Top 2 characteristics of malignant tumour
The ability to infiltrate other tissues
The ability to metastasize
Which organs are common organs for distant metastasis?
Lungs, liver, brain (highly vascularised organs)
Epithelial cancers are called
carcinomas
Non-epithelial cancers with mesenchymal origin are called
sarcomas
Tumours of glandular origin are called
adenoma (benign)
adenocarcinoma (malignant)
Papillary means
Tumour grows with frond-like pattern (long, thin, finger-like)
lipoma is
benign fat tumour
leiomyoma is
benign smooth muscle tumour
rhabdomyoma is
benign skeletal muscle tumour
liposarcoma is
malignant fat tumour
leiomyosarcoma is
malignant smooth muscle tumour
rhabdomyosarcoma is
malignant skeletal muscle tumour
lymphomas, melanomas are malignant or benign tumours?
malignant tumours
what are the indications that the tumour is squamous cell origin?
keratin pearls, pave-mented appearance, intercellular bridging
what cell product indicates a glandular origin?
mucin
Teratoma arises from
totipotent germ cell -> hair, teeth, fat, skin can be found
Paraneoplastic syndrome is
effects occurring from not where the tumour arose
epithelial dysplasia (disordered growth) means
premalignant lesion
cervical dysplasia is caused by ____ and may progress to __________ and is a ______ killer
cervical dysplasia is caused by HPV and may progress to carcinoma in-situ and is a silent killer
carcinoma in-situ means…
the tumour has NOT invaded the basement membrane; not invasive cancer
is there a sarcoma in-situ?
no, mesenchymal cells are not bounded by basement membrane
Grading of malignant tumours depends on…
their degree of differentiation
differentiation refers to the extent the tumour cells resemble the normal tissue
grade 1: ____ differentiated
grade 2: ____ differentiated
grade 3: ____ differentiated
grade 1: well differentiated
grade 2: moderately differentiated
grade 3: poorly differentiated
What are the ways for malignant cancer to metastasize?
- Local infiltration
- Hematogenous spread (through bloodstream)
- Lymphatic spread
- Spread through body cavities
Perineural infiltration means…
tumour infiltrated into the space surrounding nerves
Pagetoid spread means…
malignant epithelial cells can spread along the epidermis and other epithelial linings
Staging of a tumour involves the…
TNM system
T - how big it is (for breast cancer) / how deep it invades (for gastric cancer)
N - number of lymph nodes affected
M - metastasis yes or no (0 or 1)
Primitive (fetal/childhood) tumours are called…
blastomas
Mature teratoma is _____ while immature teratoma is _____
Mature teratoma is benign while immature teratoma is malignant (can lead to rupture and torsion)
Most carcinomas like to travel in
lymphatics
Most sarcomas like to travel in
blood vessels
What are the clinical effects of cancer?
- local effects
- hormonal effects
- cancer cachexia
- paraneoplastic syndromes
benign tumours can cause 1, 2 and 4
What are the key genes often mutated in cancer?
- proto-oncogenes
- tumour suppressor genes
- genes regulating apoptosis
- genes regulating dna repair
- genes that confer growth advantages
- genes that maintain genomic stability
Hallmark number 1: Growth signal autonomy
proto-oncogenes become oncogenes which drive proliferation of cells
- increase growth factors
- increase in growth factor receptors (HER2 increases in breast cancers)
- change in structure of growth factor receptors
- mutations of cell signalling molecules (mutations of RAS gene and BRAF and mutations that activate cyclin genes -> cells grow uncontrollably -> tumour)
- activation of transcription factors (MYC)
Hallmark 2: Evading growth suppressors
- inactivation of tumour suppressors retinoblastoma and p53
retinoblastoma protein is a key negative regulator of G1/S cell cycle - loss of function mutation
- shift from active hypophosphorylated state to inactive hyperphosphorylated state
loss of p53 function -> DNA damage goes unrepaired, accumulation of mutations
Hallmark number 3: Resisting cell death
Mutation in BCL2 gene -> BCL2 protein is anti-apoptic
Hallmark number 4: Replicative immortality
Cancer cells maintain the length of their telomeres by reactivating telomerase
Hallmark number 5: Inducing angiogenesis
Cancer cells induce angiogenesis needed for tumour survival and expansion
Oncogenes up-regulate Vascular Endothelial Growth Factor (VEGF) -> stimulate angiogenesis
Hallmark number 6: Activating invasion and metastasis
Cancer cells can invade and metastasize
Hallmark number 7: Avoiding immune destruction
Tumour cells can express PD-L1 which binds to PD-1 receptor on T cells -> suppression of T-cell response
Hallmark number 8: Reprogramming energy metabolism
Cancer cells have an altered metabolism where there is increased glucose uptake and fermentation of glucose to lactate
Hallmark number 9: Genomic instability
Cancer cell -> DNA replication error cell -> continues to divide and passes mutation to daughter cells.
Loss of MMR proteins renders DNA mismatch repair inefficient -> increase mutation rate
Loss of MMR proteins can occur through:
- loss of function mutations
- DNA promoter hypermethylation of MLH1 gene
Hallmark number 10: Tumour promoting inflammation
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What are the 6 main classes of cytotoxic chemotherapy drugs?
- Alkylating drugs
- Platinating drugs
- Anti-metabolites
- Cytotoxic Antibiotics
- Mitotic Inhibitors
- Topoisomerase Inhibitors
